Indian Patents
Title of Invention

A METHOD FOR MEASURING THE OPERATING STATE OF A SYNCHRONOUS MOTOR USING COMPOSITE POWER ANGLE METER
Abstract The present invention discloses a method for measuring the operating state of synchronous motor by using composite power angle meter, the method comprising steps of: a) obtaining various signals of the synchronous motor and its system; b) converting the electric signals into digital signals by an internal data collection part of the composite power angle meter, and inputting all the digital signals to a host computer; c) inputting related parameters or commands to the host computer by keyboard and mouse; d) calculating the related data of the motor according to a program by the host computer, obtaining the coordinates of relevant points and related data, and inputting the results to a displaying program; e) processing the coordinates of main points and the calculation results by the displaying program in the host computer, and displaying on a display a dynamic composite power angle graph and the motor-end composite magnetic leakage graph which vary with the motor's parameters. The method provided by the present invention may intuitionally reflect the operating state of the synchronous motor from both electric and mechanical aspects, and also reflect the situation of the composite magnetic leakage at the synchronous motor end.
Full Text FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
A METHOD FOR MEASURING THE OPERATING STATE
OF A SYNCHRONOUS MOTOR USING COMPOSITE
POWER ANGLE METER
WANG, Zhaolei, a Chinese citizen of Operating Department, Qin Bei Power Plant Of Huaneng, Wulongkou County, 454662 Jiyuan City, Henan Province, China
The following specification particularly describes and ascertains the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to a method for measuring the operating state of synchronous motor by using composite power angle meter, which belongs to the field of electrical engineering in electric power systems.
BACKGROUND OF THE INVENTION
In the industrial practice of electric power systems, it is necessary to constantly monitor the operating state of a synchronous motor, so as to ensure the synchronous motor to operate in an optimum state. At present, an electric power system generally adopts, at operating locales, various types of meters to display the current, voltage, power and other related electric data of the synchronous motor, especially adopts a power angle meter to measure the power angle and other related electric data of the synchronous motor, and displays the electric power angle vector graph of the synchronous motor through a TV screen (as shown in Figures 6 and 15), so as to provide intuitional electric vector graph for operators.
However, there are disadvantages in various electric measuring meters currently in use. For example, the defects of the power angle meter which is capable of displaying the electric data and electric vector graph of a salient-pole synchronous motor are:
1. The power angle meter can only display the electric power angle vector graph of the synchronous motor (as shown in Figure 6), but it cannot directly display the mechanical relationship between the stator and the rotor of the synchronous motor.
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2. Although the power angle meter can display the electric power angle vector graph of the synchronous motor and reflect the stator armature potential, magnetic excitation potential, motor-end voltage, power angle and other electric data of the synchronous motor, it cannot display, with optimum segments, the magnitudes of active power and reactive power of the synchronous motor or the magnitudes of active components and reactive components of other parameters of the synchronous motor.
3. The power angle meter cannot satisfy the requirements of various professionals working in synchronous motor monitoring and operating. With the development of electric technology, a majority of dynamotor sets in the power plants realize the centralized control by programs. Compared with the number of other professionals, the number of electric professionals working in dynamotor monitoring and operating is less and less. However, it is difficult for non-electric professionals to understand the electric power angle vector graph displayed by the power angle meter of the synchronous motor.
4. The power angle meter cannot be applied to synchronous parallel-network monitoring of the synchronous motor.
5. The power angle meter cannot display the end magnetic leakage condition of the synchronous motor.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention aims at providing a method for measuring the operating state of a synchronous motor by using composite power angle meter. The method can intuitionally reflect various operating
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states of a synchronous motor from both electric and mechanical aspects, is advantageous for operators of various specialties to dialectically understand the operation principle of the synchronous motor from both electric and mechanical aspects, provides an intuitional model for mechanical analysis of the parallel-network operating state of the synchronous motor, and provides operators with images for analyzing and monitoring the end heat-emitting condition of the synchronous motor by depicting the end composite magnetic leakage graph of the synchronous motor.
In order to achieve the above object, one aspect of the present invention provides a method for measuring the operating state of synchronous motor by using composite power angle meter, which comprises steps of:
a) Obtaining various electric signals of the synchronous motor and its system, and obtaining digital signals of related equipments;
b) Converting the electric signals into digital signals by an internal data collection part of the composite power angle meter, and inputting related digital signals to a host computer;
c) Inputting related parameters or commands to the host computer by keyboard and mouse;
d) Program-processing the related data by the computer, calculating the data by a computing program to obtain the coordinates of relevant points and related data, and inputting the results to a displaying program;
e) Using the coordinates of main points and the calculation results to depict various electric and mechanical model graphs of the synchronous motor through the displaying program process by the computer, displaying on a display a dynamic composite power angle graph which varies with the motor's parameters, and realizing an alarm
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function;
f) Using the coordinates of main points and the calculation results to depict the end composite magnetic leakage graph of the synchronous motor through the displaying program process by the computer, displaying on a display an end composite magnetic leakage graph of the synchronous motor which varies with the motor's parameters, and realizing an alarm function.
The present invention provides a method for measuring the operating state of a synchronous motor by using composite power angle meter, wherein program processes comprise a displaying program process and a computing program process; the displaying program process comprises establishing graph coordinates and imaging; and the computing program process comprises determining parameters, calculating parameters and alarming.
The above aspect of the present invention uses a composite power angle meter to obtain the stator voltage and current signals, magnetic excitation voltage and current signals, magnetic excitation adjustment signal and system voltage signal of the synchronous motor in real time, performs internal controlling programs to calculate the related parameters of the synchronous motor in real time, depicts the electric and mechanical model graphs illustrating various characteristics of the synchronous motor, depicts the end composite magnetic leakage graph of the synchronous motor, and displays the graphs on a display. Therefore, compared with conventional methods for measuring the operating state of a synchronous motor by using power angle meter, the present invention has the following advantages:
1. The present invention may intuitionally reflect the operating state of a synchronous motor from both electric and mechanical aspects. The present invention may not only
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display the electric power angle vector graph of the synchronous motor, but also display the composite power angle graph, motor mechanical model graph, motor mechanical model schematic graph and motor synchronous composite power angle graph of the synchronous motor. Compared with the graphs displayed by conventional power angle meters, the present invention can additionally display the following mechanical models: the rigid bodies of rotor and stator of the synchronous motor, the levers and springs of rotor and stator of the synchronous motor, and etc.
2 . Compared with the electric vector graph of the synchronous motor, the composite power angle graph of the synchronous motor, which is depicted for measuring the operating state of the synchronous motor by the present invention, adds mechanical model graphs of the synchronous motor and also adds the assistant lines of EqM and EdN, is easier to illustrate the power distribution, active and reactive components of stator voltage, active and reactive components of stator current, and active and reactive components of spring pull of the synchronous motor, and can also illustrate the magnitude of the variance of the magnetic excitation adjustment signal.
3. The motor operating state graphs depicted for measuring the operating state of the synchronous motor by using the composite power angle meter of the present invention are advantageous for operators of various specialties to dialectically understand the operation principle of the synchronous motor from both electric and mechanical aspects, provide intuitional models for mechanical analysis of parallel-network operating state of the synchronous motor, and may be effective tools for the magnetic excitation characteristics analysis, magnetic excitation adjustment, synchronous parallel-network, and
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operation monitoring and controlling of the synchronous motor.
4. The synchronous power angle graph of the synchronous motor depicted by the present invention may be applied in synchronous parallel-network monitoring of the synchronous motor.
5. The end composite magnetic leakage graph of the synchronous motor depicted by the present invention may be applied to analyze and monitor the end heat-emitting condition of the synchronous motor.
DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic diagram illustrating the configuration of the composite power angle meter according to the present invention;
Figure 2 is a diagram illustrating the external connection relationship of the composite power angle meter according to the present invention;
Figure 3 is a diagram illustrating the operation principle of the I/V converting circuit of the composite power angle meter according to the present invention;
Figure 4 is a diagram illustrating a detailed circuitry of the data collection part of the composite power angle meter according to the present invention;
Figure 5 is a composite power angle graph depicted for measuring the operating state of a salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 6 is an electric power angle vector graph, namely sub-figure I of the composite power angle graph depicted for measuring the operating state of the salient-pole synchronous motor by using the composite power angle
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meter according to the present invention;
Figure 7 is a motor mechanical model graph, namely sub-figure II of the composite power angle graph depicted for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 8 is a motor mechanical model schematic graph, namely sub-figure III of the composite power angle graph depicted for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 9 is a synchronous composite power angle graph, namely sub-figure IV of the composite power angle graph depicted for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 10 shows a coordinates model of the power angle graph of the salient-pole synchronous motor, which is established for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 11 is a diagram illustrating the digital symbols of the synchronous motor;
Figure 12 is a graph illustrating curves of a zero load and a zero power factor of a dynamotor;
Figure 13 is a graph illustrating the relationship between the air gap potential and the saturated reactance of the dynamotor;
Figure 14 is a composite power angle graph depicted for measuring the operating state of a non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 15 is an electric power angle vector graph, namely sub-figure I of the composite power angle graph
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depicted for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 16 is a motor mechanical model graph, namely sub-figure II of the composite power angle graph depicted for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 17 is a motor mechanical model schematic graph, namely sub-figure III of the composite power angle graph depicted for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 18 is a synchronous composite power angle graph, namely sub-figure IV of the composite power angle graph depicted for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 19 shows a coordinates model of the power angle graph of the non-salient-pole synchronous motor, which is established for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 20 is a motor-end composite magnetic leakage graph depicted for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 21 shows a motor-end composite magnetic leakage coordinates model established for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter according to the present invention;
Figure 22 is a motor-end composite magnetic leakage graph depicted for measuring the operating state of the
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non-salient-pole synchronous motor by using the composite power angle meter according to the present invention; and
Figure 23 shows a motor-end composite magnetic leakage coordinates model established for measuring the operating state of the non-salient-pole synchronous motor by using the composite power angle meter according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in Figure 1, the composite power angle meter of the present invention consists of a data collection part 1 and a computer equipment 2. The data collection part 1 performs electric signal collecting and digital signal collecting. The electric signal collecting adopts an I/V converting circuit and an A/D conversion chip, the function of which is to collect various electric signals regarding the synchronous motor, convert the electric signals into digital signals, and transfer the digital signals to the computer 2. The digital signal collecting collects digital signals of related equipments and transfers them to the computer 2. The host computer 2 stores an image displaying program and a computing program. According to the computing program, the host computer 2 performs computing on the related parameters of the synchronous motor to obtain the coordinates of related points and related data of the image, and inputs the results into the displaying program. The computer processes the coordinates of main points and the calculation results by the displaying program, displays on a display of the computer an electric model graph, a mechanical model graph and a dynamic composite power angle graph which vary with the motor's parameters and represent
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the operating state of the synchronous motor as well as the end composite magnetic leakage graph of the synchronous motor, and realizes the alarm function.
As shown in Figure 2, the composite power angle meter of the present invention is connected with the measuring devices of the electric power system through wires, and receives the electric signals outputted from the synchronous motor and the measuring devices of the electric power system (i.e. transducers), as listed in Table 1. When the electric power system may provide usable digital signals, the corresponding electric signal collecting circuit may be omitted, and the corresponding parameters can be obtained by the digital signal collecting.
Table 1: Electric signals received by and outputted from electric parameter transducers

Transducer Received signal Outputted signal
Signal source Electric signal
DC voltage transducer Synchronous motor exit TV1 Motor-end three phase line voltage UAB UBC UCA Motor-end three phase line voltageUAB UBC UCA
System TV2 System three phase line voltage UXAB UxBC UXCA System three phase line voltage UXAB UxBC UXCA
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Synchronous Magnetic Magnetic excitation
motor excitation voltage, and
exciter voltage, and operating excitation voltage and backup excitation voltage thereof uL va uB operating excitation voltage and backup excitation voltage thereof uL vG uB
Switch Magnetic Magnetic excitation
state excitation system system and
signal, and synchronous synchronous motor
switching motor exit switch exit switch state
off low potential, switching on high potential state signal UzG signal uZG uZB uDL
Exciter Magnetic Magnetic excitation
adjustment excitation adjustment signal ">
unit adjustment signal u, ux ... u. U2 ... "-
DC current synchronous Magnetic Magnetic excitation
transducer motor excitation current, and
exciter current, and operating excitation current and backup excitation current thereofIL IG IBY operating excitation current and backup excitation current thereof iL iG iBy
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AC voltage Synchronous Motor-end three Motor-end three
transducer motor exit phase line phase line voltage
TV1 voltage UAB UBC UcA effective value UabUbc Ucd
System TV2 System three System three phase
phase line line voltage
voltage uXAB UxBC UxcA effective value Ia Ib Ic xbc xca
AC current Synchronous Motro-end three Motro-end three
transducer motor exit phase current phase current
TA Ia Ib Ic effective value 1° lb
Power Synchronous Motor-end line Synchronous motor
transducer motor exit TV1 voltage UAB UBC UcA active power P
Synchronous Motor-end current Synchronous motor
motor exit TA lA 'B IC reactive power Q
Frequency Synchronous Motor-end line Motor-end voltage
transducer motor exit TV1 voltage UAB frequency *
System TV2 System line System voltage
voltage UXAB frequency fx
negative Synchronous Motor-end three Synchronous motor
sequence motor exit phase line negative sequence
voltage TV1 voltage UAB UBC UCA voltage ur
transducer
The operation of the electric signal data collecting part of the composite power angle meter mainly comprises three steps of:
1. Receiving motor signals by various electric parameter transducers and converting the signals into analogue
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current signals of 0-±20mA.
2. Converting the current signals outputted from the electric parameter transducers into voltage signals of 0-±5V by the I/V converting circuit.
3. Inputting the voltage signals of 0—±5V to a data collecting interface card, A/D converting the signals into digital data and storing them in a memory of the computer. Figure 3 illustrates the operation principle of the I/V converting circuit. When the current signals outputted from the transducer pass through resistances R1 and R2 the voltage signals of 0-±5V across R2 are transferred to an A/D conversion device.
4. Figure 4 is a diagram illustrating the operation principle of the A/D conversion device in the data collection system. The main technical requirements are:
a. obtaining the instantaneous values of the motor-
end voltage and system voltage at the same time, and
storing them in the memory of the computer to perform
calculation;
That is, the A/D conversion device of the data collection system needs to input the motor-end three phase instantaneous line voltage UAB’ UBC’ UCA and the system three phase instantaneous line voltage UXAB’ UXBC’ UXCA at the same time to the computer, and the computer performs calculation on each group of the instantaneous voltages.
b. The A/D conversion device may collect sufficient
signals, and redundant samples may be used as the backup
for temporary sampling increments.
The composite power angle meter digitizes the inputted electric signals by an A/D chip, and inputs the digitized signals to the host computer through COM or LPT. The host computer performs the computing program process and displaying program process on the inputted signals, and
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depicts the graph illustrating the operating state of the synchronous motor.
When the required calculation can be obtained from other equipments, the electric parameter collection circuit and the computing process may be omitted.
The method for measuring the operating state of the synchronous motor by using the composite power angle meter of the present invention comprises the steps of:
1. obtaining the stator voltage and current signals, magnetic excitation voltage and current signals, magnetic excitation adjustment signal, system voltage and current signals of the synchronous motor, as well as the state signals of the exit switch of the synchronous motor and its magnetic excitation circuit switch;
2 . receiving the related digital signals and electric signals by the data collection part, digitizing the electric signals, and inputting the obtained digital signals to the host computer;
3. inputting the related parameters or commands to the host computer by keyboard and mouse;
4 . performing calculation on the related parameters of the motor and performing the computing program process on the related data by the host computer; after the computing program process, inputting the obtained data to the displaying program to determine instantaneous coordinates of the main points;
5. using the coordinates of the main points to depict various electric and mechanical model graphs of the synchronous motor through the displaying program process by the host computer, and displaying on the display a dynamic composite power angle graph of the synchronous motor and the end composite magnetic leakage graph of the synchronous motor which vary with the motor's parameters.
In terms of different shapes of the motor rotor,
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synchronous motors may be classified as two classifications of salient-pole synchronous motors and non-salient-pole synchronous motors. Accordingly, composite power angle meters of synchronous motor may be classified as composite power angle meters of salient-pole synchronous motor and composite power angle meters of non-salient-pole synchronous motor.
With reference to the different types of synchronous motors, the methods for measuring the different types of motors by using the composite power angle meters will now be described in detail.
I. The method for measuring the operating state of the salient-pole synchronous motor by using the composite power angle meter comprises steps of:
1. Obtaining the stator voltage and current signals, magnetic excitation voltage and current signals, magnetic excitation adjustment signal and system voltage signal of the synchronous motor as well as the state signals of the exit switch of the synchronous motor and its magnetic excitation circuit switch through the external wires of the composite power angle meter.
2. Converting the related electric signals into digital signals through the A/D conversion chip of the data collection part of the composite power angle meter, inputting the chip-converted digital signals and the received digital signals to the host computer through COM or LPT, and performing program process on the inputted signals by the computer.
3. Inputting the related parameters or commands to the host computer by keyboard and mouse.
4. Performing the program process on the above data by the host computer.
The program process comprises two parts of displaying program and computing program, the gist of which are
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listed below:
1) The gist of the displaying program
(1) Establishing image coordinates
The composite power angle meter of the salient-pole synchronous motor can display six kinds of graphs, which respectively are: composite power angle graph of salient-pole synchronous motor, as shown in Figure 5; electric power angle vector graph, namely sub-figure I of the composite power angle graph of the salient-pole synchronous motor, as shown in Figure 6; motor mechanical model graph, namely sub-figure II of the composite power angle graph of the salient-pole synchronous motor, as shown in Figure 7; motor mechanical model schematic graph, namely sub-figure III of the composite power angle graph of the salient-pole synchronous motor, as shown in Figure 8; synchronous composite power angle graph, namely sub-figure IV of the composite power angle graph of the salient-pole synchronous motor, as shown in Figure 9; motor-end composite magnetic leakage graph of the salient-pole synchronous motor, as shown in Figure 20. In accordance with Figures 5, 6, 7, 8 and 9, the coordinates-model is established by using the data to be required, as shown in Figure 10. In accordance with Figure 20, the coordinates-model is established by using the data to be required, as shown in Figure 21.
The letters of coordinate points of Figure 5 are tabbed by 0 at the lower right corner, the letters of coordinate points of Figure 6 are tabbed by 1 at the lower right corner, the letters of coordinate points of Figure 7 are tabbed by 2 or 3 at the lower right corner, the letters of coordinate points of Figure 8 are tabbed by 4 at the lower right corner, the letters of coordinate points of Figure 9 are tabbed by 5 at the lower right corner, and the letters of coordinate points of Figure 20
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are tabbed by 20 at the lower right corner. The coordinates of the points are represented by the data to be required as follows:
Figure 5: A0(a, b) , B0(c, d), C0(e, 0), D0(0, 0), E0(f, g), F0(f, 0), G0(c, 0);
Figure 6: Ai(a, b) , C1(e, 0), D1(0, 0), E1(;f,
g);
Figure 7: A2 (a/2 ,b/2), B2 (c/2 , d/2), c2 ( e/2 , 0), D2(0, 0),
E2(F/2, g/2), A3(-a/2, - b/2), B3(-c/2 -d/2), C3(e/2, 0), E3(-f/2,-8/2);
Figure 8: A4(a, b) , B4(c, d), C4(e, 0), D4(0, 0), E4(J,
g);
Figure 9: A5(h, i), C5(j, 0), D5(0, 0);
Figure 20: T20(0, 0), X20(Xi, Yi) , Y20(X2, Y2) , Z20(X3,
Y3) •
Wherein, the power angle vector graph of the salient-pole synchronous motor as shown in Figure 6 is within the electric machine theory; the vector vertex of the
synchronous motor magnetic excitation potential E0, as shown in Figure 6, has the same planar coordinates as points A0(a, b) , Ai(a, b) and A4(a, b) ; the vector vertex
of the synchronous motor end voltage U,, as shown in Figure 6, has the same planar coordinates as points C0(e, 0), C1(e, 0) and C4(e, 0); the vector vertex 0 of the synchronous motor power angle, as shown in Figure 6, has the same planar coordinates as points D0(0, 0), Di(0, 0),
a
D2(0, 0) and D4(0, 0); the coordinates value of point A2(2 ,
b_
2 ) is half of the planar coordinates value of the vector vertex of the synchronous motor magnetic excitation
potential as shown in Figure 6; the coordinates value of
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point C2 ( e/2 , 0) is half of the planar coordinates value of
the vector vertex of the synchronous motor end voltage U as shown in Figure 6; the distance between point A5 and point D5 represents the synchronous end voltage of the synchronous motor, the distance between point C5 and point D5 represents the synchronous system voltage, and the angle 5 as shown in Figure 9 is the phase angle difference between the synchronous motor voltage and the system voltage of synchronous time.
(2) The gist of imaging
a) The coordinate points in each figure only integrate with the present figure and only image in the present figure, the image moves smoothly, and when the synchronous motor stator current is not zero, the image of Figure 5 replaces the image of Figure 9.
b) The axial center of the rigid body of the synchronous motor rotor: depicting circles by taking points D0, D2, D4 and D5 respectively as the center of the circle and taking 1/20 of the length of the segment C0D0 obtained when the synchronous motor is under rating operation as the radius (the circles are in white).
c) The rigid body of the synchronous motor rotor: depicting circles by taking points D0, D2, D4 and D5 respectively as the center of the circle and taking 1/4 of the length of the segment CoD0 obtained when the synchronous motor is under rating operation as the radius. The intersection portions of the rotor rigid body circles with the rotor rigid body axial center circles are still in white, and the rest portions are in dark blue.
d) The lever of the synchronous motor rotor: the lever is in dark blue (the same color as the rotor rigid body) , and the line width of the lever is the same as the diameter of the axial center circle; when the rotor lever
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is a T-shaped lever, the length of the top beam of the T-shaped lever in each of Figures 5, 8 and 9 is two times as much as the length of the segment D0C0 obtained when the synchronous motor is under rating operation, and the top beam is central-positioned; the intersection portion of the lever with the rotor axial center is still in white. The length of the top beam of the T-shaped lever in Figure 7 is two times as much as the length of the segment D2C2 obtained when the synchronous motor is under rating operation, and the top beam is central-positioned; the intersection portion of the lever with the rotor axial center is still in white. The 1/2 length of the top beam must not be shorter than the length of the segment C0E0, C2E2 or C4E4 in respective figure.
Points D0 and A0, points A3 and A2, points D4 and A4 and points D5 and A5 are connected by levers respectively.
e) The stator rigid body: depicting a circle by
taking point D2 as the center of the circle and taking the
1/3 length of the segment C0D0 obtained when the
synchronous motor is under rating operation as the radius.
The portion out of the intersection portion of this circle
with the rotor rigid body circle, the rotor axial center
circle and the rotor lever is in light grey.
Points C0 and D0, points C4 and D4, and points C5 and D5 are connected by thin real line respectively, and at both ends of the segments there are prolongations as long as 1/2 length of the segment CoD0 obtained when the synchronous motor is under rating operation; the intersection portions with the rotor rigid body circle and the rotor axial center circle are represented by dotted lines; the part under the thin real line is shadowed with parallel thin-short bias, while the rotor rigid body circle and the rotor axial center circle are not shadowed.
f) The stator lever: the stator lever is connected
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between points C2 and C3 with the same width as that of the rotor lever and the same color as that of the stator rigid body circle, and its intersection portion with the rotor rigid body circle and the rotor axial center circle is still in the color of the rotor rigid body circle and the rotor axial center circle.
Points C0 and D0, points C4 and D4, and points C5 and D5 are connected by black bold lines representing levers, the width of the bold line is the radius of the axial center circle, and its intersection portion with the rotor axial center circle and the rotor rigid body circle is represented by thin dotted line.
g) The spring: the spring is in black with realistic imaging; it is visualized to extend and shrink according to the lengthening and shortening of the spring; there ought to be an obvious joint between the spring and the lever.
Points B0 and Co, points E0 and Co, points B2 and C2, points E2 and C2, points B3 and C3, points E3 and C3, points B4 and C4, and points E4 and C4 are connected with springs respectively.
h) The joint between the spring and the lever: the joint between the spring and the lever is represented by a white circle, the diameter of the circle is slightly shorter than the diameter of the lever, the circle is positioned at the axial centers of the lever and the spring, and its connection with the spring is obviously visualized. The distances from the center of the circle on top of the lever representing the joint to both sides of the lever equal to the distances from the center to the ends of the lever.
i) The segments: points E0 and F0, points B0 and Go, and points C0 and G0 are connected by thin black lines respectively.
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j) The vectors: linking points D1 and A1 by a segment with an arrow pointing to Ai; linking points E1 and A1 by a segment with an arrow pointing to Ai; linking points C1 and E1 by a segment with an arrow pointing to E1; linking points D1 and C1 by a segment with an arrow pointing to C1. Segment E1A1 is under segment D1A1. Points T20 and X20 are linked by a black bold segment with an arrow pointing to X2o; points T2o and Y2o are linked by a black bold segment with an arrow pointing to Y2o; points T2o and Z2o are linked by a colorful bold segment with an arrow pointing to Z20; points X20 and Z20 and points Y20 and Z20 are linked by black thin dotted segments respectively.
k) The marks of the coordinate points:
Point A0 for "E0", point B0 for "Ed”, point C0 for "U", point D0 for "0", point E0 for "Eq”, point F0 for "M", and point G0 for "N";
Point A1 upper for "E0,", lower for "Ed", point C1 for
"U", point D1 for "0", and point E1 for "Eq";
Point A2 for "BD0", point B2 for "Σd", point C2 for "ΣΣ", point D2 for "0", and point E2 for "Σq”;
ΣΣD Point A4 for "ΣΣ0", point B4 for "Σd, point C4 for
"ΣΣ", point D4 for "0", and point E4 for "Σq";
Point A5 for "E0", point C5 for "U", and point D5 for "0"; and
Points X20, Y20 and Z20 for "Σ0", "ΣV' and “Σ"
respectively.
The marks move with the moving of the positions of the coordinate points, and the relative positions of the marks and corresponding coordinate points keep constant.
1) The power angle marks: the dotted line representing the power angle passes through the center of
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the rotor, superposing the axial center of the lever, and being not longer than 1/3 of the length of segment CoD0 obtained when the synchronous motor is under rating operation. It is marked as "δ" within the range of the power angle, the levers at both sides of the power angle are connected by an arc, the vertex of the arc varies as the positions of the levers vary, the radius of the arc is longer than the radius of the rotor rigid body circle, and the center of the arc superposes the stator axial center.
m) The magnetic excitation adjustment signal marks:
Two methods:
(a) In accordance with the abrupt change algorithm, depending on the length percentage by which AE0 takes the present magnetic excitation potential, when AE0 is greater than a given value it reveals the abrupt change of the magnetic excitation potential; when AE0 is positive, the adjustment signals are arranged from the top of the magnetic excitation lever to the rotor axial center, and when ΔE0 is negative, the adjustment signals are arranged from the rotor axial center along the reverse direction of the magnetic excitation potential. On the displaying screen shown in Figure 5, the adjustment signals and their colors are marked.
(b) In accordance with the adjustment algorithm and the calculation results of the computer, by the values

of E01, E02 …. Eon the adjustments are represented with
different colors and arranged depending on the length percentages they take; the increment-adjustment signals are closely arranged from the top of the magnetic excitation lever to the rotor axial center in sequence, and the reduction-adjustment signals are linearly and closely arranged from the rotor axial center along the reverse direction of the magnetic excitation potential in
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sequence, as shown in Figure 5. On the displaying screen shown in Figure 5, the adjustment signals and their colors are marked.
n) The PQ curve mark: as shown in Figure 10, determining the curve between points M0 and No according to the end heat-emitting limit of the synchronous motor and the greatest operation power angle of the synchronous motor that the system permits, determining the N0O0 curve according to the greatest active power that the synchronous motor permits, determining the 00Po curve according to the greatest stator magnetic flux, the greatest stator current and the greatest stator potential that the synchronous motor permits, and determining the O0P0 curve according to the greatest rotor magnetic flux, the greatest rotor current and the greatest rotor voltage that the synchronous motor permits. Points M0 and Q0 are both on the line D0G0, and points G0 and Q0 are connected by a thin line. Curve M0N000PoQo (exclusive of the linear segment MoQo) is depicted by a bold real line, the color of which is determined according to the user's requirement.
o) The composite magnetic leakage alarm circle: depicting a circle by taking T2o as the center of the circle and taking the greatest magnetic leakage flux that the synchronous motor permits as the radius; this circle is the alarm circle, which is represented by a colorful bold curve.
p) The synchronous image requirements: depicting
dotted circles by taking point D5 as the center of the
circle and taking segments D5A5 and D5C5 as the radius respectively. When is so big that the position of the


lever D5A5 cannot be distinguished, the lever scanning
portion outside the motor rotor rigid body is covered by
24


misty light blue; when is so small that the position of the lever D5A5 can be distinguished, it can be represented by the graph shown in Figure 9.
Q) The mechanical model as shown in Figure 7 may rotate anticlockwise dynamically, the ratio of the rotation speed of the model and that of the real object is marked on the screen, and the rotation speed ratio may be selected.
R) The image alarm display: when an alarm is given on electric parameters or magnetic flux, the marks turn to red flickers, the speaker of the computer whistles, and the corresponding segments in the composite power angle graph and its sub-figures turn to red flickers; and when the alarm is relieved, the alarm marks or segments stay red but without flicker. When alarms are given on various parameters, the corresponding alarm segments shown in Figure 10 can be referred to Table 2, and the images corresponding to the composite power angle graph or its sub-figures give alarms with red flickers; and when the alarms are relieved, the alarm images stay red but without flicker. When a parameter is clicked by the mouse, the corresponding segment shown in Figure 10 turns to the alarm color (with reference to Table 2), and the images corresponding to the composite power angle graph and its sub-figures turn red. When an alarm is given on magnetic
leakage, segment T20Z20 turns red, and mark Σ turns red.
Table 2 Alarm table of the composite power angle graph of the salient-pole synchronous motor

Alarm Composite Composite Composite Composite Composite
parameter E power power power power E power
angle angle angle angle angle
graph graph graph graph graph
25

sub- sub- sub- sub-
1 figure I figure II figure III figure IV
Synchrono D0C0 D1C1 D5A5(T-
us motor shaped
end lever)
Voltage Uab
ubc u„
Synchrono D0C0 C2C3 D4C4 D5A5(T-
us motor shaped
stator lever)
composite
magnetic
flux
Synchrono D0A0(T- D1A1 D5A5(T-
us motor shaped shaped
magnetic lever) lever)
excitatio
n voltage
and
Current uL iL
Synchrono D0A0(T- A2A3(I- D4A4(T- D5A5(T-
us motor shaped shaped shaped shaped
rotor lever) lever) lever) lever)
magnetic
flux
System D5C5
voltage
vmb uxbc um
Synchrono E0C0 and
us motor C0B0
26

stator
current Ia
Ib Ic
Synchrono E0Fo and
us motor B0G0
active
power P
Synchrono F0C0 and
us motor C0G0
reactive
power Q
s) The digital mark display image: depicting the primary graph of the motor as shown in Figure 11, marking the displayed letters, displaying corresponding data of the displayed letters after the letters; the actual value and the per-unit value may be switched; when an alarm is given, the marks and numbers turn to red flickers, and the speaker of the computer whistles, and when the alarm is relieved, the marks and numbers stay red but without flicker. The conditions of displaying the marks and numbers are:
(a) After the parallel-network of the synchronous motor, namely when a motor exit breaker DL shuts on, the state signal uDL of the motor exit breaker DL is at high level, the motor exit breaker DL turns blue, and the digital display image does not display the letter-marks and numbers of the voltage (Uxab Uxbc Uxca) and frequency (fx) at the system side, while displaying other marks and numbers.
(b) During the parallel-off or the parallel-network of the synchronous motor, namely when the motor exit breaker DL shuts off, the state signal UDL of the motor
27

exit breaker DL is at low level, and the mark of the motor exit breaker DL turns white and displays all the marks and numbers.
(c) When an operating excitation switch or a
backup excitation switch of the synchronous motor turns
on, its state signal Uza or uzB is at high level, and the corresponding switch turns blue; when the magnetic
excitation switch turns off, its state signal UzG or uZB is at low level, and the mark of the corresponding switch turns white.
(d) When the synchronous motor exit breaker DL
shuts off, the digital display value of the synchronous
motor rotor magnetic flux Σ0 is made equal to the value of the total stator magnetic flux ΣΣ. When the synchronous motor exit breaker DL shuts on, the calculation value is displayed as the value of the synchronous motor rotor
magnetic flux Σ0".
In accordance with the afore-mentioned imaging requirements, the six graphs as shown in Figures 5, 6, 7, 8, 9 and 20 can be obtained through program process. These six graphs can be combined with each other according to the requirements of the user, and any one of the combined images can be further combined with the digital display image of Figure 11. Adjustments may be made within a small range on the stator radius and rotor radius, the axial center radius of the stator and of the rotor, the diameter of the lever and the spring joint radius of the synchronous motor, which are given in Figures 5, 7, 8 and 9; the models shown in Figures 5, 7, 8 and 9 may be made as various three-dimensional mechanical models; and the color of the models may be adjusted according to the requirements of the user.
2) Gist of the computing program
28

(1) Determination of the parameters

Given parameters: the leakage reactance Xa of the
motor stator (Potier reactance), quadrature-axis
synchronous reactance Xq synchronous motor voltage,

current and frequency conversion coefficients Ku, K1 and
Kw, system voltage and frequency conversion coefficients
K K
xu and Xm, active and reactive power conversion
K K K
coefficients F, Q and m, the conversion coefficients
K K K
L , GL and BL of the magnetic excitation voltage and the
operating excitation voltage and backup excitation voltage
of the synchronous motor, the conversion coefficients f,
K K
Gf and Bf of the magnetic excitation current and the
operating excitation current and backup excitation current of the synchronous motor, negative sequence voltage
conversion coefficient F, the synchronous conversion
K K
coefficients r and N of the synchronous motor end
is
voltage, the synchronous conversion coefficients XT and
K K
m of the system voltage, the conversion coefficient TJ
of the voltage of the magnetic excitation adjustment signal, and magnetic flux leakage coefficients K1, K2 and K3. Allowable range of main parameters: main parameters comprise motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux, power angle, system voltage and so on. Rating parameters of the motor mainly comprise: motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux, system voltage


and so on.
(2) Calculation of the parameters
a) pj = Kpp , ΣP = Km.Pj
b) Qj=KQQ , ΣQ = KmQJ
c) Iaj ~ KiIa Ibj ~ KiIb Icj = KiIc
d) UabJ = KvUah Uhcj = KUUhc Ucaj = KUUca

e)If = Kfil, IGf = KGfiG, Ibf = KBfiBY

f) F = Kwf Fx =KXwfx
g) uFj = KFUF
h) uxaJ= kXUuXab, Uxbcj= Kxu Uxbc, Uxcaj= KxuUxca1u*, =Kxi,uxhcuxcaj
i) uLj = KLUL, UGJ = KGLUG, UBJ = KBLUB
(3) Determination of the value of the direct-axis synchronous reactance Xd of the salient-pole synchronous motor
Two methods for determining the value of the direct-axis synchronous reactance Xd of the salient-pole synchronous motor are:
a) Directly determining the value of the direct-axis synchronous reactance Xd in accordance with the air gap potential Eδ obtained when the synchronous motor is under normal operation, and the value of Xd being kept constant.
b) Determining the value of Xd through the value of E5 in accordance with the function relationship between the air gap potential Eδ of the synchronous motor and the direct-axis synchronous reactance Xd, and comprising the steps of:
(a) Recording the dynamotor zero load (ia = 0 )
curve and the zero power factor (la = lN) curve as shown in Figure 12, namely curve U=f0(If) and curve U=fN{I/).
(b) Determining the function relationship
30

between the air gap potential E5 of the synchronous motor and the direct-axis synchronous reactance Xd.
In accordance with the curves U=f o (I/} and U=fN(If) , taking n magnetic excitation current values of If1, If2... Ifn, and determining on the curve U=fN(If) points
B1, B2 ... Bn corresponding to If1, If2... Ifn, based on the zero power factor curve. Constructing n congruent triangles through points B, Bi, B2 ... Bn respectively (wherein segment CD is vertical to the I-coordinate, and CD = IN *Xa ) , intersecting with the zero load characteristic curve of U= fo(If) at points C, C1, C2, ... Cn respectively, connecting points 0 and C1, and extending segment OC1 to intersect with the line that passes through point Bi and is parallel to the U-coordinate at point Ai; similarly, connecting points 0 and C2, ... connecting points 0 and Cn, and extending segment 0C2 ... extending 0Cn, and intersecting with the lines that pass through points B2 ... Bn respectively and are parallel to the U-coordinate at points A2 ... An respectively.
Therefore, the synchronous saturated reactance


corresponding to Eδ1, Eδ2 . .. Eδn respectively are:


.Depicting the relationship graph of the air gap potential and the reactance in accordance with

the relationship between Eδ1, Eδ2 . .. Eδn and respective
corresponding synchronous saturated reactance Xd1, Xd2, Xdn , as shown in Figure 13. The function Xd= f(E5) can be determined by this curve.
(c) Computing E.

31

K,=e+jI,,*Xa . E, =|E,|
(d) Substituting the value of E5 into function Xd= f (E5) to obtain the value of Xd. (4) Calculations
a) H=e + jiaJ*X,=HZS s{90°)S)-90°) can be determined by this equation
h = K, sin( /, = /„ cos(S + cp)
a = (e*cosS + Ij * X d) * cos S
6=(e*cosiS +/,, * Jf,,)*sin c = e + I. * X . * cos S
d = IJ*XJ*sinS

f = e * cos 5 g = Y«*sin 25
Calculations of components of the magnetic excitation
Two calculation methods are:
(a) Abrupt change algorithm
Assuming the average magnetic excitation potential of the synchronous motor during the period of AT from some certain time till now as SE0, and the current magnetic excitation potential being Eo; assuming = Eo~ SEo. The value of AT and the times of sampling the magnetic excitation potential may be set.
(b)Adjustment algorithm Assuming the total automatic magnetic excitation adjustment of the integrated amplifier as SU;
U' -KTJU2r
f _ KTJV2 Jl~ ZU
the components respectively are: = TJ '
Af = K„U,
■ X - KTJU„ . su= KTJ (Ul+U2+...+Un) , A ~
n ~~ LU

Calculating

/, Va 2 + b1 Em = f2 -Ja2 + b '


£o„=/*Va2+62

32

k) Calculation of coordinates of the magnetic flux leakage
Xi=K!a; Yi=Kib; X2=K2 (f-a) +K3 (c-a) ; Y2=K2 (g-b)+K3 (d-b); X3=Xi+X2; Y3=Y!+Y2
1) Calculation of the per-unit value of the magnetic flux: assuming when the frequency is at the rating value, the per-unit value of a certain magnetic flux of the synchronous motor equals to the per-unit value of the corresponding voltage; determining the per-unit values of the magnetic excitation flux and the stator total magnetic flux of the motor according to the relationship among frequency, voltage and magnetic flux, and displaying the per-unit values with digitals; comparing the calculated values with the given values, and alarming when the calculated values are larger than the given values.
m) Calculations of the per-unit values of various parameters according to the requirements.
(5) During the synchronous parallel-network or
parallel-off, namely when « = '»= * =0, performing the following calculations on each set of the synchronous motor voltage and the system voltage inputted to the computer:
/av U = KT(uAB + uBCZl20" +uCAZ240") = UZa

(b) °* = K xriUxAB + "XBCZUO" + uXCAZ240°) = U xZe
■y- = M-zs
(C)

2 _ !+;+-■„ _
(d) * " (wherein 0l°2'"0" are the values of the first, the second ... and the nth sx measured within a
certain time period; when a second measured value enters,
the value of the first "' is abandoned, and when the next
measured value enters, the value of the second * is abandoned; analogically, the new measured values replace
33

the old ones; and the time period and the value of n can be set. )
(e) A = £„£/„„ *cos (f) I = KNV abj*smSx (Q\ J - K.wU,„(,,
(6) Comparing various electric parameters with respective given values, and alarming when the electric parameters are out of the prescribed ranges.
II. The method for measuring the operating state of the non-salient-pole synchronous motor by using the non-salient-pole composite power angle meter comprises steps of:
1. Obtaining the stator voltage and current signals, magnetic excitation voltage and current signals, magnetic excitation adjustment signal and system voltage signal of the synchronous motor as well as the state signals of the exit switch of the synchronous motor and its magnetic excitation circuit switch through the external wires of the composite power angle meter.
2. Converting the related electric signals into digital signals through the A/D conversion chip of the data collection part of the composite power angle meter, inputting the chip-converted digital signals and the received digital signals to the host computer through COM or LPT, and performing program process on the inputted signals by the computer.

3. Inputting the related parameters or commands to the host computer by keyboard and mouse.
4. Performing the program process on the above data by the host computer.
The program process comprises two parts of displaying program and computing program, the gist of which are listed below:
34

1) The gist of the displaying program (1) Establishing image coordinates
The composite power angle meter of the non-salient-pole synchronous motor can display six kinds of graphs, which respectively are: composite power angle graph of non-salient-pole synchronous motor, as shown in Figure 14; electric power angle vector graph, namely sub-figure I of the composite power angle graph of the non-salient-pole synchronous motor, as shown in Figure 15; motor mechanical model graph, namely sub-figure II of the composite power angle graph of the non-salient-pole synchronous motor, as shown in Figure 16; motor mechanical model schematic graph, namely sub-figure III of the composite power angle graph of the non-salient-pole synchronous motor, as shown in Figure 17; synchronous composite power angle graph, namely sub-figure IV of the composite power angle graph of the non-salient-pole synchronous motor, as shown in Figure 18; motor-end composite magnetic leakage graph of the non-salient-pole synchronous motor, as shown in Figure 22. In accordance with the common characteristics of these figures, the coordinates-model is established by using the data to be required, as shown in Figure 19. In accordance with the characteristic of Figure 22, the coordinates-model is established by using the data to be required, as shown in Figure 23. The letters of coordinate points of Figure 14 are tabbed by 10 at the lower right corner, the letters of coordinate points of Figure 15 are tabbed by 11 at the lower right corner, the letters of coordinate points of Figure 16 are tabbed by 12 or 13 at the lower right corner, the letters of coordinate points of Figure 17 are tabbed by 14 at the lower right corner, the letters of coordinate points of Figure 18 are tabbed by 15 at the lower right corner, and the letters of coordinate points of Figure 22 are tabbed by 22 at the lower right corner.
35

The coordinates of the points are represented by the data to be required as follows:
Figure 14: A10(a, b) , Ci0(e, 0), D10(0, 0), Gi0(a, 0) ;
Figure 15: An (a, b) , Cn(e, 0), Dn(0, 0) ;
Figure 16: A12 ( *" , M, C12 ( ^ , 0), D12(0, 0), A13 ,
C13(_t, 0);
Figure 17: A14(a, b) , Ci4(e, 0), D14(0, 0) ;
Figure 18: A15(h, i) , C15(j, 0), D15(0, 0);
Figure 22: T22(0, 0), X22(Xi, Yi) , Y22(X2, Y2) , Z22(X3, Y3) •
Wherein, the power angle vector graph of the non-salient-pole synchronous motor as shown in Figure 15 is within the electric machine theory; the vector vertex of
the synchronous motor magnetic excitation potential ^, as shown in Figure 15, has the same planar coordinates as points A10 (a, b) , A11 (a, b) and A14 (a, b) ; the vector vertex
of the synchronous motor end voltage U, as shown in Figure 15, has the same planar coordinates as points Ci0(e, 0), Cn(e, 0) and Ci4(e, 0); the vector vertex O of the synchronous motor power angle, as shown in Figure 15, has the same planar coordinates as points D10 (0, 0), DU(0, 0), D12 (0, 0) and D14 (0, 0); the coordinates value of point
2- JL
A12(2 , 2 ) is half of the planar coordinates value of the vector vertex of the synchronous motor magnetic excitation
potential ^ as shown in Figure 15; the coordinates value
e
of point C12(2 , 0) is half of the planar coordinates value of the vector vertex of the synchronous motor end voltage
^ as shown in Figure 15; the distance between point A15 and point D15 represents the synchronous end voltage of the
36

synchronous motor, the distance between point Ci5 and point D15 represents the synchronous system voltage, and the angle 5 as shown in Figure 18 is the phase angle difference between the synchronous motor voltage and the system voltage of synchronous time. (2) The gist of imaging
a) The coordinate points in each figure only integrate with the present figure and only image in the present figure, the image moves smoothly, and when the synchronous motor stator current is not zero, the image of Figure 14 replaces the image of Figure 18.
b) The axial center of the rigid body of the synchronous motor rotor: depicting circles by taking points D10, D12, D14 and D15 respectively as the center of the circle and taking 1/20 of the length of the segment C10D10 obtained when the synchronous motor is under rating operation as the radius (the circles are in white).
c) The rigid body of the synchronous motor rotor: depicting circles by taking points D10, D12, C14 and D15 respectively as the center of the circle and taking 1/5 of the length of the segment C10D10 obtained when the synchronous motor is under rating operation as the radius. The intersection portions of the rotor rigid body circles with the rotor rigid body axial center circles are still in white, and the rest portions are in dark blue.
d) The lever of the synchronous motor rotor: the lever is in dark blue (the same color as the rotor rigid body), and the line width of the lever is the same as the diameter of the axial center circle; the intersection portion of the lever with the rotor axial center is still in white.
Points C10 and A10, points A12 and A13, points A14 and D14and points A15 and D15 are connected by levers respectively.
37

e) The stator rigid body: depicting a circle by
taking point D12 as the center of the circle and taking the
1/3 length of the segment C10D10 obtained when the
synchronous motor is under rating operation as the radius.
The portion out of the intersection portion of this circle
with the rotor rigid body circle, the rotor axial center
circle and the rotor lever is in light grey.
Points C10 and D10, points C14 and D14, and points C15 and D15 are connected by thin real line respectively, and at both ends of the segments there are prolongations as long as 1/2 length of the segment C10D10 obtained when the synchronous motor is under rating operation; the intersection portions with the rotor rigid body circle and the rotor axial center circle are represented by dotted lines; the part under the thin real line is shadowed with parallel thin-short bias, while the rotor rigid body circle and the rotor axial center circle are not shadowed.
f) The stator lever: the stator lever is connected
between points C12 and D13 with the same width as that of
the rotor lever and the same color as that of the stator
rigid body, and its intersection portion with the rotor
rigid body circle and the rotor axial center circle is
still in the color of the rotor rigid body circle and the
rotor axial center circle.
Points C10 and D10, points C14 and D14, and points C15 and D15 are connected by black bold lines representing levers, the width of the bold line is the radius of the axial center circle, and its intersection portion with the rotor axial center circle and the rotor rigid body circle is represented by thin dotted line.
g) The spring: the spring is in black with realistic
imaging; it is visualized to extend and shrink according
to the lengthening and shortening of the spring; there
ought to be an obvious joint between the spring and the
38

lever.
Points C10 and Cm, points Ai2 and C12, points Ai3 and C13, and points Ai4 and Ci4 are connected with springs respectively.
h) The joint between the spring and the lever: the joint between the spring and the lever is represented by a white circle, the diameter of the circle is slightly shorter than the diameter of the lever, the circle is positioned at the axial centers of the lever and the spring, and its connection with the spring is obviously visualized. The distances from the center of the circle on top of the lever representing the joint to both sides of the lever equal to the distances from the center to the ends of the lever respectively.
i) The segments: points A10 and G10 and points do and G10 are connected by thin black lines respectively.
j) The vectors: linking points Dn and An by a segment with an arrow pointing to An; linking points Dn and Cn by a segment with an arrow pointing to Cn; linking points Cn and An by a segment with an arrow pointing to Cn. Points T22 and X22 are linked by a black bold segment with an arrow pointing to X22; points T22 and Y22 are linked by a black bold segment with an arrow pointing to Y22," points T22 and Z22 are linked by a colorful bold segment with an arrow pointing to Z22," points X22 and Z22 and points Y22 and Z22 are linked by black thin dotted segments respectively.
k) The marks of the coordinate points:
A10 for nE0", point C10 for "U", point D10 for "0", and point do for "M";
Point An for "4", point Cn for "{/", and point Dn for "0"; segment Audi for "£«";
39

Point A12 for "2J>0", point Ci2 for "ZBt>", and point Di2 for "0";
Point A14 for "2H>0", point Ci4 for "£2fl>", and point Di4 for "0";
Point A15 for "E0", point Ci5 for "U", and point D1S for "0";
The marks of the magnetic leakage composite graph: points X22, Y22 and Z22 for "1%,", "3^" and "BI^" respectively.
The marks move with the moving of the positions of the coordinate points, and the relative positions of the marks and corresponding coordinate points keep constant.
1) The power angle marks: the dotted line representing the power angle passes through the center of the rotor, superposing the axial center of the lever, and being not longer than 1/3 of the length of segment C10D10 obtained when the synchronous motor is under rating operation. It is marked as "5" within the range of the power angle, the levers at both sides of the power angle are connected by an arc, the vertex of the arc varies as the positions of the levers vary, the radius of the arc is longer than the radius of the rotor rigid body circle, and the center of the arc superposes the stator axial center, m) The magnetic excitation adjustment signal marks: Two methods:
(a) In accordance with the abrupt change algorithm, depending on the length percentage by which AE0 takes the present magnetic excitation potential, when AE0 is greater than a given value it reveals the abrupt change of the magnetic excitation potential; when AE0 is positive, the adjustment signals are arranged from the top of the magnetic excitation lever to the rotor axial center, and when AE0 is negative, the adjustment signals are arranged
40

from the rotor axial center along the reverse direction of the magnetic excitation potential. On the displaying screen shown in Figure 14, the adjustment signals and their colors are marked.
(b) In accordance with the adjustment algorithm and the calculation results of the computer, by the values
E E K
of 01, °2 ... ^", the adjustments are represented with
different colors and arranged depending on the length percentages they take; the increment-adjustment signals are closely arranged from the top of the magnetic excitation lever to the rotor axial center in sequence, and the reduction-adjustment signals are linearly and closely arranged from the rotor axial center along the reverse direction of the magnetic excitation potential in sequence, as shown in Figure 14. On the displaying screen shown in Figure 14, the adjustment signals and their colors are marked.
n) The PQ curve mark: determining the curve between points M10 and N10 according to the end heat-emitting limit of the synchronous motor and the greatest operation power angle of the synchronous motor that the system permits, determining the N10O10 curve according to the greatest active power that the synchronous motor permits, determining the O10P10 curve according to the greatest stator magnetic flux, the greatest stator current and the greatest stator potential that the synchronous motor permits, and determining the P10Q10 curve according to the greatest rotor magnetic flux, the greatest rotor current and the greatest rotor voltage that the synchronous motor permits. Points Mi0 and Q10 are both on the line D10G10, and points G10 and Q10 are connected by a thin line. Curve M10N10O10P10Q10 (exclusive of the linear segment M10Qio) is depicted by a bold real line, the color of which is
41

determined according to the user's requirement.
o) The composite magnetic leakage alarm circle: depicting a circle by taking T22 as the center of the circle and taking the greatest magnetic leakage flux that the synchronous motor permits as the radius; this circle is the alarm circle, which is represented by a colorful bold curve.
p) The synchronous image requirements: depicting dotted circles by taking point Di5 as the center of the circle and taking segments D15A15 and D15C15 as the radius
ddx
respectively. When lever Di5A15 cannot be distinguished, the lever scanning
portion outside the motor rotor rigid body is covered by
as, misty light blue; when the lever D15A15 can be distinguished, it can be represented
by the graph shown in Figure 18.
q) The mechanical model as shown in Figure 16 may rotate anticlockwise dynamically, the ratio of the rotation speed of the model and that of the real object is marked on the screen, and the rotation speed ratio may be selected.
r) The image alarm display: when an alarm is given on electric parameters or magnetic flux, the marks turn to red flickers, the speaker of the computer whistles, and the corresponding segments in the composite power angle graph and its sub-figures turn to red flickers; and when the alarm is relieved, the alarm marks or segments stay red but without flicker. When alarms are given on various parameters, the corresponding alarm segments shown in Figure 19 can be referred to Table 3, and the images corresponding to the composite power angle graph or its sub-figures give alarms with red flickers; and when the
42

alarms are relieved, the alarm images stay red but without flicker. When a parameter is clicked by the mouse, the corresponding segment shown in Figure 19 turns to the alarm color (with reference to Table 3), and the images corresponding to the composite power angle graph and its sub-figures turn red. When an alarm is given on magnetic
leakage, segment T22Z22 turns red, and mark ^T* turns red.
Table 3 Alarm table of the composite power angle graph of the non-salient-pole synchronous motor

Alarm Composite Composite Composite Composite Composit
parameter e power power power power e power
angle angle angle angle angle
graph graph graph graph graph
sub- sub- sub- sub-
figure I figure II figure III figure IV
Synchrono D10C10 DiiCn D15A15
us motor
end
voltage^"4
ubl u„
Synchrono D10C10 C12C13 D14C14 D15A15
us motor
stator
composite
magnetic
flux
Synchrono D10Aio DiiAu D15A15
us motor
magnetic
43

excitatio
n voltage
and
current " Synchrono D10A10 Ai2A13 D14A14 D15A15
us motor
rotor
magnetic
flux
System D15Ci5
voltage
^ * u„
Synchrono C10A10
us motor
stator
current '••
h /«
Synchrono A10G10
us motor
active
power P
Synchrono C10G10
us motor
reactive
power Q
s) The digital mark display image: depicting the primary graph of the motor as shown in Figure 11, marking the displayed letters, displaying corresponding data of the displayed letters after the letters; the actual value and the per-unit value may be switched; when an alarm is given, the marks and numbers turn to red flickers, and the
44

speaker of the computer whistles, and when the alarm is relieved, the marks and numbers stay red but without flicker. The conditions of displaying the marks and numbers are:
(a) After the parallel-network of the synchronous motor, namely when a motor exit breaker DL shuts on, the state signal UOL of the motor exit breaker DL is at high level, the motor exit breaker DL turns blue, and the digital display image does not display the letter-marks and numbers of the voltage (Uxab UXbC Uxca) and frequency (Jx) at the system side, while displaying other marks and numbers.
(b) During the parallel-off or the parallel-network of the synchronous motor, namely when the motor exit breaker DL shuts off, the state signal UDL of the motor exit breaker DL is at low level, and the mark of the motor exit breaker DL turns white and displays all the marks and numbers.
(c) When an operating excitation switch or a backup excitation switch of the synchronous motor turns on, its state signal Uza or uv> is at high level, and the corresponding switch turns blue; when the magnetic
excitation switch turns off, its state signal Um or u^ is at low level, and the mark of the corresponding switch turns white.
(d) When the synchronous motor exit breaker DL
shuts off, the digital display value of the synchronous
motor rotor magnetic flux ™ is made equal to the value of the total stator magnetic flux 22^. When the synchronous motor exit breaker DL shuts on, the calculation value is displayed as the value of the synchronous motor rotor
magnetic flux *.
In accordance with the afore-mentioned imaging
45

requirements, the six graphs as shown in Figures 14, 15, 16, 17, 18 and 22 can be obtained through program process. These six graphs can be combined with each other according to the requirements of the user, and any one of the combined images can be further combined with the digital display image of Figure 11. Adjustments may be made within a small range on the stator radius and rotor radius, the axial center radius of the stator and of the rotor, the diameter of the lever and the spring joint radius of the synchronous motor, which are given in Figures 14, 16, 17 and 18; the models shown in Figures 14, 16, 17 and 18 may be made as various three-dimensional mechanical models; and the color of the models may be adjusted according to the requirements of the user.
2) Gist of the computing program (1) Determination of the parameters
Given parameters: the leakage reactance a of the motor stator, synchronous motor voltage, current and
K K K
frequency conversion coefficients u, ' and °, system
K K
voltage and frequency conversion coefficients xu and x active and reactive power conversion coefficients p, Q
K K K K
and m, the conversion coefficients l, GL and Bl of the
magnetic excitation voltage and the operating excitation voltage and backup excitation voltage of the synchronous
K K K
motor, the conversion coefficients f , G/ and Bf of the
magnetic excitation current and the operating excitation current and backup excitation current of the synchronous motor, the computing coefficient m of the synchronous motor, negative sequence voltage conversion coefficient
K K K
F, the synchronous conversion coefficients T and N of
the synchronous motor end voltage, the synchronous

JC K
conversion coefficients -"" and m of the system voltage,
the conversion coefficient TJ of the voltage of the magnetic excitation adjustment signal, and magnetic flux leakage coefficients K1 and K2. Allowable range of main parameters: main parameters comprise motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux, power angle and system voltage. Rating parameters of the motor mainly comprise: motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux and -system voltage.
(2) Calculation of the parameters

a) Pj=KPP 1 I,P = KmPl
b) Qj = KQQ 1 ZQ = KmQj
c) IhJ=K,Ibf ICJ=K,IC
d) UabJ = KvUah UbcJ = KvUhc Ucaj = KVU„1 1
e) If=KfiL 1 *Gf ~ K-GflG *Bf ~~ ^BflBY 1
f) f ' X ~ "•XaJx
g) UFJ = KFUF
h) Uxabj = ^xijUxah U xbcj = ^XU^xbc *-> xcaj = K w Uxca1 1
i ) "L, = KLUL uGJ — KGluG uBj — KBLuB
(3) Determination of the value of the direct-axis synchronous reactance Xd of the non-salient-pole synchronous motor
Two methods for determining the value of the direct-axis synchronous reactance Xd of the non-salient-pole synchronous motor are:
a) Directly determining the value of the direct-
47

axis synchronous reactance Xd in accordance with the air gap potential E5 obtained when the synchronous motor is under normal operation, and the value of Xd being kept constant.
b) Determining the value of Xd in accordance with the function relationship between the air gap potential E5 of the synchronous motor and the direct-axis synchronous reactance Xd, and comprising the steps of:
(a) Recording the dynamotor zero load (ia =0 )
curve and the zero power factor {ia = iN ) curve as shown in Figure 12, namely curve U=f0(If) and curve U=fN(I/).
(b) Determining the function relationship
between the air gap potential E5 of the synchronous motor
and the direct-axis synchronous reactance Xd.
In accordance with the curves U=fo(If) and U=fN(I/) , taking n magnetic excitation current values of
fi, fl ... f" , and determining on the curve U=fN(I/) points
Bi, B2 ... Bn corresponding to n, n ... >based on the zero power factor curve. Constructing n congruent triangles through points B, Bi, B2 ... Bn respectively (wherein segment CD is vertical to the I-coordinate, and CD = lN*Xa),
intersecting with the zero load characteristic curve of U= fo(If) at points C, Ci, C2, ... Cn respectively, connecting points 0 and Ci, and extending segment OC1 to intersect with the line that passes through point Bi and is parallel to the U-coordinate at point Ai; similarly, connecting points 0 and C2, ... connecting points 0 and Cn, and extending segment OC2 ... extending 0Cn, and intersecting with the lines that pass through points B2 ... Bn respectively and are parallel to the U-coordinate at points A2 ... An respectively.
Therefore, the synchronous saturated reactance
48

F F F -^ /i — ~7—
corresponding to g> , S1 ... *> respectively are: " ,
X =ML X = A"B" dl '» ... " !N . Depicting the relationship graph of
the air gap potential and the reactance in accordance with
F F F
the relationship between *•, S1 ... *• and respective
X X
corresponding synchronous saturated reactance Jx , J2 ...
y
(c) Computing E5. Let W = P]+jQj=WZ Then iaj = ^(-

tt=e + jii*Xa . E, =|E,|
r
(d) Substituting the value of E5 into function Xd= f (E5) to obtain the value of Xd. (4) Calculations , , a = e + %-Xd
a ) me d
b) b = ^XJ
c) Calculations of components of the magnetic
excitation
Two calculation methods are:
(a) Abrupt change algorithm
Assuming the average magnetic excitation potential of the synchronous motor during the period of AT from some certain time till now as SE0/ and the current magnetic excitation potential being Eo; assuming AE0= Eo~ SE0. The value of AT and the times of sampling the magnetic excitation potential may be set.
(b) Adjustment algorithm
Assuming the total automatic magnetic excitation adjustment of the integrated amplifier as EU;
49

the components respectively are: AU-KTJ^\/ U'-KTJUlf ¥ = KTJU, ■■■ x = KTJU„ . su= KTJ(Ui+u2+...+un), •^=~si/~L, fi=~b
f - Kuu-
J n 111
Calculating E°> = f^"1 + >>2 f Em = f2y/a2 +b2
d) Calculation of the per-unit value of the magnetic flux: assuming when the frequency is at the rating value, the per-unit value of a certain magnetic flux of the synchronous motor equals to the per-unit value of the corresponding voltage; determining the per-unit values of the magnetic excitation flux and the stator total magnetic flux of the motor according to the relationship among frequency, voltage and magnetic flux; comparing the calculated values with the given values, and alarming when the calculated values are larger than the given values.
e) comparing various electric parameters with respective given values, and alarming when the electric parameters are larger than the given values.
f) Calculation of the coordinates of the magnetic flux leakage
Xi=Kia; Yi=Kib; X2=K2(e-a); Y2=-K2b; X3=Xi+X2; Y3=Y!+Y2
(5) During the synchronous parallel-network or
parallel-off, namely when /aj U = KT(uM +MflCZ120° +uCAZ240") = UZa
(b) °* = Kxr("xAB + "«cZ120° + U,.C/,240°) = UxZe (C) »'
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(d) * " (wherein °>°2 " " are the values of
the first, the second ... and the nth sx measured within a
certain time period; when a second measured value enters,
the value of the first °\ is abandoned, and when the next
measured value enters, the value of the second s* is abandoned; analogically, the new measured values replace the old ones; and the time period and the value of n can be set. )
(e) ft = KNUabj*cosSx
(f) i = K NU ahJ * sin Sx
(6) Comparing various electric parameters with respective given values, and alarming when the electric parameters are out of the prescribed ranges.
Compared with the single electric power angle vector graph depicted by the conventional power angle meter for measuring the operating state of the motor, the electric model graph, mechanical model graph and motor-end composite magnetic leakage graph depicted by the composite power angle meter of the present invention for measuring the operating state of the synchronous motor have the following advantages:
Comparisons are made in terms of the salient-pole synchronous motor and the non-salient-pole synchronous motor, respectively.
1. The comparison between the composite power angle meter of the salient-pole synchronous motor and the conventional power angle meter
a) The composite power angle meter of the salient-pole synchronous motor may display six graphs, and it displays not only the composite power angle of the salient-pole synchronous motor, but also the sub-figures
51

of the composite power angle, with reference to Figure 5 to Figure 9; and it realizes the functions of image-alarming and sound-alarming. The PQ curve in the composite power angle graph of Figure 5 defines the locus range of the vertex Eo of the magnetic excitation lever, the composite magnetic leakage graph in Figure 20 defines the composite magnetic leakage range of the stator and rotor that the end heat-emitting of the synchronous motor permits, thus providing intuitional limit graph of the motor parameters for operators; however, the conventional power angle meter only displays the electric vector graph, as shown in Figure 6.
b) The composite power angle graph (Figure 5) displayed by the composite power angle meter of the salient-pole synchronous motor has double significations: in one aspect, it represents the electric power angle vector graph of the salient-pole synchronous motor, and in another aspect, it represents the mechanical power angle graph showed with the magnetic flux. The power angle represented by the composite power angle graph of the salient-pole motor has both electric and mechanical characteristics. However, the conventional power angle graph only shows electric vectors and only reflects the electric characteristics of the power angle.
c) The graphs displayed by the composite power angle meter further comprise the mechanical model graph of the synchronous motor, in addition to the electric vector graph. The stator and rotor levers in the mechanical model as shown in Figure 7 are the total composite magnetic flux
££ 4m*V 4m*V
springs are * and 9'd respectively (wherein m is the
52

phase number of the motor stator, KW represents the
effective turns of the stator coil, and q and d are the quadrature-axis and direct-axis synchronous inductance coefficients of the motor respectively), and the graph simulates the anticlockwise rotations of the motor stator and rotor. The mechanical models shown in Figure 5 and Figure 8 take the stator as a reference object, the stator
lever and rotor lever are £E and ° respectively, and the elasticity coefficients of the quadrature-axis and
2m*V 2m*V
direct-axis springs are " and 9>d respectively.
The mechanical power angle graph intuitionally reveals the mutual effective relationship between the motor stator and the motor rotor from mechanical aspect, and operators may refer to the mechanical model to understand the principle of the operating of the motor and adjust motor parameters precisely.
d) Compared with the electric vector graph, the composite power angle graph further includes assistant lines, as shown in Figure 5.
i. If the lengths of OE0 and OU represent the magnetic excitation potential and the end voltage of the dynamotor respectively, UEq and UEd represent the quadrature-axis component and direct-axis component of the stator potential of the synchronous motor respectively, and EqM and MU represent the active component and reactive component of the stator quadrature-axis potential of the synchronous motor, point M on segment OU or superposing point U respectively represent that the inductive reactive power done by the quadrature-axis potential is negative or zero, point Eq above, below or on the line OU respectively represent that the active power done by the quadrature-axis potential is positive, negative or zero; EdN and NU
53

represent the active component and reactive component done by the stator direct-axis potential of the synchronous motor respectively, point N on the segment OU, on the extension of the segment OU or superposing point U respectively represent that the inductive reactive power done by the direct-axis potential is negative, positive or zero, and point Ed above, below or on the line OU respectively represent that the active power done by direct-axis potential is positive, negative or zero, ii. If the lengths of OEo and OU represent the magnetic excitation flux and the total composite magnetic flux in the stator coil of the dynamotor respectively, UEq and UEd respectively represent the quadrature-axis component and direct-axis component of the composite magnetic flux generated by the reaction of the stator armature of the synchronous motor.
iii. If the lengths of OEo and OU represent the rotor lever and stator lever of the synchronous motor respectively, UEq and UEd respectively represent the extended lengths of the springs by which the rotor lever of the synchronous motor pulls the stator lever along directions of quadrature-axis and direct-axis, and segments EqM and EdN respectively represent the active length components generated by the extensions of the quadrature-axis spring and direct-axis spring, anticlockwise and clockwise pulls generate positive active power and negative active power respectively, segments MU and UN respectively represent the reactive components generated by the extensions of the quadrature-axis spring and direct-axis spring, the pull along the direction from point 0 to point U generates positive inductive reactive power, and the pull along the direction from point U to point 0 generates the negative inductive reactive power. Generally, the sum of EqM±EdN may be regarded as the active
54

power, and the sum of MU±UN may be regarded as the reactive power, wherein x+' is adopted when forces generated by the springs orient the same direction, and ' is adopted when forces generated by the springs orient opposite to each other.
e) Compared with electric vector graph (Figure
6), the composite power angle graph of the salient-pole
synchronous motor (Figure 5) additionally includes the
graph of the magnetic excitation adjustment signal.
By adding the magnetic excitation adjustment display, the operators are assisted to check the operating state of the automatic magnetic excitation adjuster intuitionally, judge the influence of the adjustment signal on the stable operation of the electric power system, and adjust the magnetic excitation accurately and duly in case of accident.
f) The newly added synchronous image (Figure 9)
intuitionally shows the relative position of the rotor
rigid body magnetic lever of the synchronous motor and the
magnetic lever of the electric power system, which may
assist the operators to adjust the rotation speed and end
voltage of the motor accurately.
2 . The comparison between the composite power angle meter of the non-salient-pole synchronous motor and the conventional power angle meter
a) The composite power angle meter of the non-salient-pole synchronous motor may display six graphs, and it displays not only the composite power angle of the non-salient-pole synchronous motor, but also the sub-figures of the composite power angle, with reference to Figure 14 to Figure 18; and it realizes the functions of image-alarming and sound-alarming. The PQ curve in the composite power angle graph of Figure 14 defines the locus range of the vertex Eo of the magnetic excitation lever, the
55

composite magnetic leakage graph in Figure 22 defines the composite magnetic leakage range of the stator and rotor that the end heat-emitting of the synchronous motor permits, thus providing intuitional limit graph of the motor parameters for operators; however, the conventional power angle meter only displays the electric vector graph, as shown in Figure 15.
b) The composite power angle graph (Figure 14) displayed by the composite power angle meter of the non-salient-pole synchronous motor has double significations: in one aspect, it represents the electric power angle vector graph of the non-salient-pole synchronous motor, and in another aspect, it represents the mechanical power angle graph showed with the magnetic flux. The power angle of the synchronous motor represented by the composite power angle graph of the non-salient-pole motor has both electric and mechanical characteristics. However, the conventional power angle graph (Figure 15) only shows electric vectors and only reflects the electric characteristics of the power angle.
c) The graphs displayed by the composite power angle meter further comprise the mechanical model graph of the synchronous motor, in addition to the electric vector graph displayed by the conventional power angle meter. Thus, the mutual effective relationship between the motor stator and the motor rotor can be intuitionally revealed from mechanical aspect. The stator and rotor levers in the mechanical model as shown in Figure 16 are the total composite magnetic flux SZO and magnetic excitation
composite magnetic flux ° in the motor stator respectively, the elasticity coefficient of the spring is
—gj— (wherein m is the phase number of the motor stator, I™ represents the effective turns of the stator coil, and
56

I is the synchronous inductance coefficient of the motor),
and the graph simulates the anticlockwise rotations of the motor stator and rotor. The mechanical models shown in Figure 14 and Figure 17 take the stator as a reference
object, the stator lever and rotor lever are 2SO and ° respectively, and the elasticity coefficient of the spring
2m*V
is —$—.
The mechanical power angle graph intuitionally reveals the mutual effective relationship between the motor stator and the motor rotor from mechanical aspect, and operators may refer to the mechanical model to understand the principle of the operating of the motor and adjust motor parameters precisely.
d) Compared with the electric vector graph, the composite power angle graph further includes assistant lines, as shown in Figure 14.
i. The lengths of OEo and OU represent the magnetic excitation potential and the end voltage of the motor respectively, and E0U, E0M and UM represent the stator potential of the motor, the active component and reactive component of the stator potential respectively; point M on the segment OU, on the extension of the segment OU or superposing point U represent that the motor generates capacitive reactive power, inductive reactive power or zero reactive power respectively. Point E0 above, below or on line OU respectively represent that the motor is a dynamotor, is an electromotor, or has zero active power.
ii. The lengths of OEo and OU represent the magnetic excitation flux lever and the total magnetic flux lever in the stator coil of the motor respectively, and E0U, EoM and UM represent the extended length of the mechanical lever spring of the dynamotor, the active component and reactive
57

component of the extended length of the spring respectively; point M on the segment OU, on the extension of the segment OU or superposing point U represent that the motor generates capacitive reactive power, inductive reactive power or zero reactive power respectively. Point E0 above or below the lever OU or on the line OU respectively represent that the spring has an anticlockwise torsion, has a clockwise torsion or has no torsion with respect to the stator, and that the motor operates in manner of a dynamotor, an electromotor or zero active power.
iii. If the length of UE0 represents the value of the apparent power W of the motor, the lengths of E0M and UM represent the values of the active power and reactive power of the dynamotor respectively.
iv. If the length of UE0 represents the value of the stator current I of the motor, the lengths of E0M and UM represent the values of the active component IP and reactive component IQ of the stator current of the motor respectively.
v. Compared with electric vector graph (Figure 15), the composite power angle graph of the non-salient-pole synchronous motor (Figure 14) additionally includes the graph of the magnetic excitation adjustment signal.
By adding the magnetic excitation adjustment display, the operators are assisted to check the operating state of the automatic magnetic excitation adjuster intuitionally, judge the influence of the adjustment signal on the stable operation of the electric power system, and adjust the magnetic excitation accurately and duly in case of accident.
vi. The newly added synchronous image (Figure 18) intuitionally shows the relative position of the rotor rigid body magnetic lever of the synchronous motor and the
58

magnetic lever of the electric power system, which may assist the operators to adjust the rotation speed and end voltage of the motor accurately.
INDUSTRIAL APPLICABILITY
The present invention may intuitionally reflect the operating state of the synchronous motor from both electric and mechanical aspects, and may reveal the end composite magnetic leakage situation of the synchronous motor. Compared with the electric vector graph, the composite power angle graph of the motor depicted by the present invention further includes the mechanical model graph of the synchronous motor, which is helpful for operators of various specialties to dialectically analyze the operating state of the synchronous motor from both electric and mechanical aspects; the end composite magnetic leakage graph of the synchronous motor depicted by the present invention is helpful for operators to analyze and monitor the end heat-emitting situation of the synchronous motor. The method provided by the present invention may, in the electric power system industry, be an effective tool for users to apply in the analysis of the magnetic excitation characteristics, the magnetic excitation adjustment, the synchronous parallel-network, the operation monitoring and controlling, and other tasks of the synchronous motor, so as to enable the synchronous motor to operate in an optimum state.
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I CLAIM
1. A method for measuring the operating state of
synchronous motor by using composite power angle meter,
comprising the steps of:
a. Obtaining various electric signals and digital
signals of the synchronous motor and its system;
b. Converting the electric signals into digital
signals by an internal data collection part of the
composite power angle meter, and inputting all the
obtained digital signals to a host computer;
c. Inputting related parameters or commands to the
host computer by keyboard and mouse;
d. Program-processing the related data by the
computer, calculating the data by a computing program to
obtain the coordinates of relevant points and related
data, and inputting the results to a displaying program;
e. Using the coordinates of main points and the
calculation results to depict an electric model graph, a
mechanical model graph and a motor-end composite magnetic
leakage graph of the synchronous motor through the
displaying program process by the computer, displaying on
a display a dynamic composite power angle graph and the
motor-end composite magnetic leakage graph which vary with
the motor's parameters, and realizing an alarm function.
2. The method for measuring the operating state of synchronous motor by using composite power angle meter according to Claim 1, characterized in that the displaying program process comprises establishing coordinates of images and imaging; and the computing program process comprises determining parameters, calculating parameters, determining the value of the direct-axis synchronous reactance of the synchronous motor and alarming.
3. The method for measuring the operating state of synchronous motor by using composite power angle meter
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according to Claim 2, characterized in that the displaying program process and computing program process comprise the following steps for a non-salient-pole synchronous motor: The displaying program process including: (1) Establishing image coordinates of composite power angle graph, electric power angle vector graph, motor mechanical model graph, motor mechanical model schematic graph, synchronous composite power angle graph and motor end composite magnetic leakage graph of the non-salient-pole synchronous motor:
Composite power angle graph: Ai0(a, b) , Ci0(e, 0), D10(0, 0), G10(a, 0);
Electric power angle vector graph: An (a, b), Cn(e, 0), Du(0, 0);
Motor mechanical model graph: Ai2 ( 2 , 2 ), Ci2 ( 2 , 0),
Di2(0, 0), A13(~^r "£), Ci3(_t, 0);
Motor mechanical model schematic graph: Ai4(a, b), C14(e, 0), Di4(0, 0);
Synchronous composite power angle graph: Ai5(h, i) , Cis(j, 0), D15(0, 0);
Motor end composite magnetic leakage graph: T22(0, 0), X22(Xi, Yi), Y22(X2, Y2), Z22(X3, Y3);
Wherein, points Ai0, An and Ai4 indicate the planar coordinates of the vector vertex of the synchronous motor magnetic excitation potential;
Points C10, Cn and Ci4 indicate the planar coordinates of the vector vertex of the synchronous motor end voltage;
Points D10, Dn, D12 and D14 indicate the planar coordinates of the vector vertex of the synchronous motor power angle;
Point Ai2 indicates the planar coordinates of the vector midpoint of the synchronous motor magnetic excitation potential;
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Point C12 indicates the planar coordinates of the vector midpoint of the synchronous motor end voltage;
The distance between points A15 and D15 indicates the synchronous end voltage of the synchronous motor, and the distance between points C15 and D15 indicates the synchronous system voltage; and
T22f X22; Y22 and Z22 are the image coordinates of the motor end composite magnetic leakage graph; (2) The gist of imaging
a) The coordinate points in each figure only integrate with the present figure and only image in the present figure, the image moves smoothly;
b) The axial center of the rigid body of the synchronous motor rotor: depicting circles by taking points D10, D12, D14 and D15 respectively as the center of the circle and taking 1/20 of the length of -the segment C10D10 obtained when the synchronous motor is under rating operation as the radius; and the circles are in white;
c) The rigid body of the synchronous motor rotor: depicting circles by taking points D10, D12, D14 and D15 respectively as the center of the circle and taking 1/5 of the length of the segment CioD10 obtained when the synchronous motor is under rating operation as the radius; the intersection portions of the rotor rigid body circles with the rotor rigid body axial center circles are still in white, and the rest portions are in dark blue;
d) The lever of the synchronous motor rotor: the lever is in dark blue (the same color as the rotor rigid body) , and the line width of the lever is the same as the diameter of the axial center circle; the intersection portion of the lever with the rotor axial center is still in white;
Points D10 and Am, points Ai2 and A13, points Ai4 and D14 and points A15 and D15 are connected by levers
62

respectively;
e) The stator rigid body: depicting a circle by
taking point Di2 as the center of the circle and taking the
1/3 length of the segment C10D10 obtained when the
synchronous motor is under rating operation as the radius;
the portion out of the intersection portion of this circle
with the rotor rigid body circle, the rotor axial center
circle and the rotor lever is in light grey;
Points C10 and D10, points Ci4 and Di4, and points Ci5 and D15 are connected by thin real line respectively, and at both ends of the segments there are prolongations as long as 1/2 length of the segment CioD10 obtained when the synchronous motor is under rating operation; the intersection portions with the rotor rigid body circle and the rotor axial center circle are represented by dotted lines; the part under the thin real line is shadowed with parallel thin-short bias, while the rotor rigid body circle and the rotor axial center circle are not shadowed;
f) The stator lever: the stator lever is connected
between points Ci2 and C13 with the same width as that of
the rotor lever and the same color as that of the stator
rigid body, and its intersection portion with the rotor
rigid body circle and the rotor axial center circle is
still in the color of the rotor rigid body circle and the
rotor axial center circle;
Points C10 and D10, points Ci4 and Di4, and points C15 and D15 are connected by black bold lines representing levers, the width of the bold line is the radius of the axial center circle, and its intersection portion with the rotor axial center circle and the rotor rigid body circle is represented by thin dotted line;
g) The spring: the spring is in black with realistic imaging; it is visualized to extend and shrink according to the lengthening and shortening of the spring;
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there ought to be an obvious joint between the spring and the lever;
Points A10 and Ci0, points Ai2 and Ci2, points Ai3 and Ci3, and points Ai4 and Ci4 are connected with springs respectively;
h) The joint between the spring and the lever: the joint between the spring and the lever is represented by a white circle, the diameter of the circle is slightly shorter than the diameter of the lever, the circle is positioned at the axial centers of the lever and the spring, and its connection with the spring is obviously visualized; the distances from the center of the circle on top of the lever representing the joint to both sides of the lever equal to the distances from the center to the ends of the lever respectively;
i) The segments: points Ai0 and G10 and points C10 and G10 are connected by thin black lines respectively;
j) The vectors: linking points Dn and An by a segment with an arrow pointing to An; linking points Dn and Cn by a segment with an arrow pointing to Cu; linking points Cn and An by a segment with an arrow pointing to Cu, points T22 and X22 are linked by a black bold segment with an arrow pointing to X22; points T22 and Y22 are linked by a black bold segment with an arrow pointing to Y22; points T22 and Z22 are linked by a colorful bold segment with an arrow pointing to Z22; points X22 and Z22 and points Y22 and Z22 are linked by black thin dotted segments respectively;
k) The marks of the coordinate points:
A10 for " E0", point Ci0 for "U", point D10 for "0", and point do for "M";
Point An for "4,", point Cn for "£/", and point Du for
64

"O"; segment Audi for "£«";
Point A12 for "m>0", point C12 for "E3t", and point Di2 for "0";
Point A14 for "Sifc", point Ci4 for "Z5H>", and point Di4 for "0";
Point Ai5 for "E0", point ds for "U", and point Di5 for "0";
The marks of the magnetic leakage composite graph: points X22, Y22 and Z22 for "3%", "3^" and "Bt^" respectively;
The marks move with the moving of the positions of the coordinate points, and the relative positions of the marks and corresponding coordinate points keep constant;
1) The power angle marks: the dotted line representing the power angle passes through the center of the rotor, superposing the axial center of the lever, and being not longer than 1/3 of the length of segment C10D10 obtained when the synchronous motor is under rating operation; it is marked as "5" within the range of the power angle, the levers at both sides of the power angle are connected by an arc, the vertex of the arc varies as the positions of the levers vary, the radius of the arc is longer than the radius of the rotor rigid body circle, and the center of the arc superposes the stator axial center; m) The magnetic excitation adjustment signal marks: Two methods:
(a) In accordance with the abrupt change algorithm, depending on the length percentage by which AE0 takes the present magnetic excitation potential, when AE0 is greater than a given value it reveals the abrupt change of the magnetic excitation potential; when AE0 is positive, the adjustment signals are arranged from the top of the
65

magnetic excitation lever to the rotor axial center, and when AE0 is negative, the adjustment signals are arranged from the rotor axial center along the reverse direction of the magnetic excitation potential;
(b) In accordance with the calculation results
p
obtained by the adjustment algorithm, by the values of 01,
F F
02 ... ^", the adjustments are represented with different
colors and arranged depending on the length percentages they take; the increment-adjustment signals are closely arranged from the top of the magnetic excitation lever to the rotor axial center in sequence, and the reduction-adjustment signals are linearly and closely arranged from the rotor axial center along the reverse direction of the magnetic excitation potential in sequence;
On a displaying screen the colors of the adjustment signals are marked;
n) The PQ curve mark: determining the curve between points Mio and Ni0 according to the end heat-emitting limit of the synchronous motor and the greatest operation power angle of the synchronous motor that the system permits, determining the Ni0Oi0 curve according to the greatest active power that the synchronous motor permits, determining the O10P10 curve according to the greatest stator magnetic flux, the greatest stator current and the greatest stator potential that the synchronous motor permits, and determining the P10Q10 curve according to the greatest rotor magnetic flux, the greatest rotor current and the greatest rotor voltage that the synchronous motor permits; points Mio and Q10 are both on the line D10G10, and points Q10 and Q10 are connected by a thin line; Curve M10N10O10P10Q10 (exclusive of the linear segment M10Q10) is depicted by a bold real line, the color of which is determined according to the user's requirement;
66

o) The composite magnetic leakage alarm circle: depicting a circle by taking T22 as the center of the circle and taking the greatest magnetic leakage flux that the synchronous motor permits as the radius; this circle is the alarm circle, which is represented by a colorful bold curve;
p) The synchronous image requirements: depicting dotted circles by taking point D15 as the center of the circle and taking segments D15A15 and D15C15 as the radius respectively;
q) The mechanical model may rotate anticlockwise dynamically, the ratio of the rotation speed of the model and that of the real object is marked on the screen, and the rotation speed ratio may be selected;
r) The image alarm display: when an alarm is given on electric parameters or magnetic flux, the marks turn to red flickers, the speaker of the computer whistles, and the corresponding segments in the composite power angle graph and its sub-figures and the magnetic leakage graph turn to red flickers; and when the alarm is relieved, the alarm marks or segments stay red but without flicker;
s) In accordance with the afore-mentioned imaging requirements, the six graphs obtained through program process can be combined with each other according to the requirements of the user, and any one of the combined images can be further combined with the digital display image of Figure 11; adjustments may be made within a small range on the stator radius and rotor radius, the axial center radius of the stator and of the rotor, the diameter of the lever and the spring joint radius of the synchronous motor, which are given in the composite power angle graph and its sub-figures; the mechanical model graphs may be made as various three-dimensional mechanical model graphs; and the color of the models may be adjusted
67

according to the requirements of the user;
The computing program process including:
(1) Determination of the parameters
y Given parameters: the leakage reactance CT of the
motor stator, synchronous motor voltage, current and
K K K
frequency conversion coefficients u , ' and m, system
K K
voltage and frequency conversion coefficients xu and Xo>,
K K
active and reactive power conversion coefficients f, Q
K K K K
and m, the conversion coefficients £, GL and BL of the
magnetic excitation voltage and the operating excitation voltage and backup excitation voltage of the synchronous
K K K
motor, the conversion coefficients f, G/ and Bf of the
magnetic excitation current and the operating excitation current and backup excitation current of the synchronous motor, the computing coefficient m of the synchronous motor, negative sequence voltage conversion coefficient
K K K
F, the synchronous conversion coefficients T and N of
the synchronous motor end voltage, the synchronous
K K
conversion coefficients -"" and m of the system voltage,
is
the conversion coefficient TJ of the voltage of the
magnetic excitation adjustment signal, and magnetic flux leakage coefficients K1 and K2; allowable range of main parameters: main parameters comprise motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux, power angle and system voltage; rating parameters of the motor mainly comprise: motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux

and system voltage;
(2) Calculation of the parameters

a) i ZP = KmPj
b) QJ=KQQ *Q = KmQj
c) hi = K,Iqr hj - Kih lc) = K,IC
d) Uabl = KvUab Uhcj = KvUhc Ucaj = KvUca1 f
e) I,=K,iL *Gf ~ ^-GflG *Bf ~ K-BflBY f
f) i FX ~ KXmfx
g) UFJ = KFUF
h) U xabj = ^XU^xab "xbcj = ^ m'-' xbc ^ xcaj = ^ XU ^ xca
i) "LJ = KL"L UGj = KGLUG UBj ~ KBLUB
(3) The value of the direct-axis synchronous reactance Xd of the non-salient-pole synchronous motor
Two methods for determining the value of the direct-axis synchronous reactance Xd of the non-salient-pole synchronous motor are:
a) Directly determining the value of the direct-axis synchronous reactance Xd in accordance with the air gap potential E5 obtained when the synchronous motor is under normal operation, and the value of Xd being kept constant;
b) Determining the value of Xd in accordance with the function relationship between the air gap potential E5 of the synchronous motor and the direct-axis synchronous reactance Xd, and comprising the steps of:
(a) Depicting the dynamotor zero load (ia =o )
curve and the zero power factor (la = iN) curve, namely
curve U=fo(If) and curve U=fN(I/);
(b) Determining the function relationship
between the air gap potential Es of the synchronous motor
and the direct-axis synchronous reactance Xd;
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In accordance with the curves U=f0(If) and U=fN(If) , taking n magnetic excitation current values of
fi, /2 ... i" , and determining on the curve U=fN(I/) points
Bi, B2 ... Bn corresponding to f' , /2 ... f" based on the zero power factor curve; constructing n congruent triangles through points B, Bi, B2 ... Bn respectively (wherein segment CD is vertical to the I-coordinate, and CD = IN*Xa ) , intersecting with the zero load characteristic curve of U= fo(I/) at points C, Ci, C2, ... Cn respectively, connecting points 0 and Ci, and extending segment OC1 to intersect with the line that passes through point Bi and is parallel to the U-coordinate at point Ai; similarly, connecting points 0 and C2, ... connecting points 0 and Cn, and extending segment OC2 ... extending 0Cn, and intersecting with the lines that pass through points B2 ... Bn respectively and are parallel to the U-coordinate at points A2 ... An respectively;
Therefore, the synchronous saturated reactance
F F F -**■ i) — ~~i—
corresponding to X -M2, x = A"B" dl '" ... " ,fl ; depicting the relationship graph of
the air gap potential and the reactance in accordance with
F F F
the relationship between Si , S2 ... 6n and respective
X X
corresponding synchronous saturated reactance (c) Computing E5 Let #*Pj+JQ,=W*P. U°=lt = e; Then i« = 'i*-V)f
£s=e + jiaj*Xa . E, =|E,|
(d) Substituting the value of E5 into function Xd= f (E5) to obtain the value of Xd;
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(4) Calculations
* = « + £*,
b) °--A
c) Calculations of components of the magnetic excitation
Two calculation methods are: (a) Abrupt change algorithm Assuming the average magnetic excitation potential of the synchronous motor during the period of AT from some certain time till now as SE0, and the current magnetic excitation potential being Eo; assuming AE0= Eo~ SEo; the value of AT and the times of sampling the magnetic excitation potential may be set;
(b) Adjustment algorithm Assuming the total automatic magnetic excitation adjustment of the integrated amplifier as SU;
the components respectively are: AU = KTJUif U =KTJUI/
&f = KTJU3 ■X = KTJV„. su= KTJ(Ui+U2+...+Un) , ^=~vT, A =~«7i ...
f — KTJUn
J n ZV
Calculating E» = /, Va2 + * 2 f Em = /2Va2 + *2 ...
E0n =/„V^TfcT
d) Calculation of the per-unit value of the magnetic flux: assuming when the frequency is at the rating value, the per-unit value of a certain magnetic flux of the synchronous motor equals to the per-unit value of the corresponding voltage; determining the per-unit values of the magnetic excitation flux and the stator total magnetic flux of the motor according to the relationship among frequency, voltage and magnetic flux; comparing the calculated values with the given values, and alarming when the calculated values are larger than the given values;
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e) comparing various electric parameters with respective given values, and alarming when the electric parameters are larger than the given values;
f) Calculation of the coordinates of the magnetic flux leakage
Xi=Kia; Yi= K1b; X2=K2(e-a); Y2=-K2b; X3=X!+X2; Y3=Yi+Y2
(5) During the synchronous parallel-network or
parallel-off, namely when ° = *= c=0, performing the following calculations on the synchronous motor voltage signal and the system voltage signal inputted to the computer:
,aj U = KT(uM + uK.Z\20° +uCA^240") = U/la
(b) °* = *"(«*» + ««C^120° + «AC,Z240°) = UxZe

(C)



S _ Sl+S2+-S„ _ _ _
(d) * " (wherein °'°^"°n are the values of
the first, the second ... and the nth sx measured within a
certain time period; when a second measured value enters,
the value of the first s* is abandoned, and when the next
measured value enters, the value of the second si is abandoned; analogically, the new measured values replace the old ones; and the time period and the value of n can be set.)
(e) h = K»Uat,j*C0S#,
jfj i= KflUabJ*smSx
( g \ J ~ % XN U xahj
(6) Comparing various electric parameters with respective given values, and alarming when the electric parameters are out of the prescribed ranges. 4. The method for measuring the operating state of synchronous motor by using composite power angle meter
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according to Claim 2, characterized in that the displaying program process and computing program process comprise the following steps for a salient-pole synchronous motor: The displaying program process including: (1) Establishing image coordinates of composite power angle graph, electric power angle vector graph, motor mechanical model graph, motor mechanical model schematic graph, synchronous composite power angle graph and motor end composite magnetic leakage graph of the salient-pole synchronous motor:
Composite power angle graph: A0(a, b), B0(c, d), C0(e, 0), D0(0, 0), E0(f, g), F0(J, 0), G0(c, 0);
Electric power angle vector graph: Ai(a, b), Ci(e, 0), K1 K0, 0), E1 (f, g);
Motor mechanical model graph: A2 ( 2 , 2 ), B2(2 , 2 ),
C2(*, 0), D2(0, 0), E2(T, M, A3(~^r ~%), B3(~*, ~^),
C3(-"2", 0), E3(~T, ~ M;
Motor mechanical model schematic graph: A4(a, b), B4(c, d), C4(e, 0), D4(0, 0), E4('f, g);
Synchronous composite power angle graph: A5(h, i), C5(j, 0), D5(0, 0) ;
Motor end composite magnetic leakage graph: T20(0, 0), X20(Xi, Yi), Y20(X2, Y2), Z20(X3, Y3);
Wherein, points A10, A11 and A14 indicate the planar coordinates of the vector vertex of the synchronous motor magnetic excitation potential; points C10, C11 and C14 indicate the planar coordinates of the vector vertex of the synchronous motor end voltage; points D0, Di, D2 and D4 indicate the planar coordinates of the vector vertex of the synchronous motor power angle; point A2 indicates the planar coordinates of the vector midpoint of the synchronous motor magnetic excitation potential; point C2
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indicates the planar coordinates of the vector midpoint of the synchronous motor end voltage; the distance between A5 and D5 indicates the synchronous end voltage of the synchronous motor, the distance between C5 and D5 indicates the synchronous system voltage; and T20, X2o, Y20 and Z2o are the image coordinates of the motor end composite magnetic leakage graph;
(2) The gist of imaging
a) The coordinate points in each figure only integrate with the present figure and only image in the present figure, the image moves smoothly;
b) The axial center of the rigid body of the synchronous motor rotor: depicting circles by taking points D0, D2, D4 and D5 respectively as the center of the circle and taking 1/20 of the length of the segment C0Do obtained when the synchronous motor is under rating operation as the radius;
c) The rigid body of the synchronous motor rotor: depicting circles by taking points D0, D2, D4 and D5 respectively as the center of the circle and taking 1/4 of the length of the segment C0D0 obtained when the synchronous motor is under rating operation as the radius;
d) The lever of the synchronous motor rotor: the lever is in dark blue (the same color as the rotor rigid body) , and the line width of the lever is the same as the diameter of the axial center circle; when the rotor lever is a T-shaped lever, the length of the top beam of the T-shaped lever in each of the composite power angle graph, motor mechanical model schematic graph and synchronous composite power angle graph is two times as much as the length of the segment D0C0 obtained when the synchronous motor is under rating operation, and the top beam is central-positioned; the length of the top beam of the T-shaped lever in the motor mechanical model graph is two
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times as much as the length of the segment D2C2 obtained when the synchronous motor is under rating operation, and the top beam is central-positioned;
Points D0 and A0, points A3 and A2, points D4 and A4 and points D5 and A5 are connected by levers respectively;
e) The stator rigid body: depicting a circle by
taking point D2 as the center of the circle and taking the
1/3 length of the segment C0D0 obtained when the
synchronous motor is under rating operation as the radius;
Points C0 and D0, points C4 and D4, and points C5 and D5 are connected by thin real line respectively, and at both ends of the segments there are prolongations as long as 1/2 length of the segment C0D0 obtained when the synchronous motor is under rating operation; the intersection portions with the rotor rigid body circle and the rotor axial center circle are represented by dotted lines; the part under the thin real line is shadowed with parallel thin-short bias, while the rotor rigid body circle and the rotor axial center circle are not shadowed;
f) The stator lever: the stator lever is connected between points C2 and C3 with the same width as that of the rotor lever; points C0 and D0, points C4 and D4, and points C5 and D5 are connected by black bold lines representing levers, the width of the bold line is the radius of the axial center circle, and its intersection portion with the rotor axial center circle and the rotor rigid body circle is represented by thin dotted line;
g) The spring: the spring is in black with realistic imaging; it is visualized to extend and shrink according to the lengthening and shortening of the spring; there ought to be an obvious joint between the spring and the lever;
Points Bo and Co, points E0 and Co, points B2 and C2, points E2 and C2, points B3 and C3, points E3 and C3, points
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B4 and C4, and points E4 and C4 are connected with springs respectively;
h) The joint between the spring and the lever: the joint between the spring and the lever is represented by a white circle, the diameter of the circle is slightly shorter than the diameter of the lever, the circle is positioned at the axial centers of the lever and the spring, and its connection with the spring is obviously visualized; the distances from the center of the circle on top of the lever representing the joint to both sides of the lever equal to the distances from the center to the ends of the lever;
i) The segments: points E0 and F0, points B0 and G0, and points C0 and Go are connected by thin black lines respectively;
j) The vectors: linking points Di and Ai by a segment with an arrow pointing to Ai; linking points E1 and Ax by a segment with an arrow pointing to Ai; linking points Ci and E1 by a segment with an arrow pointing to G1; linking points Di and Ci by a segment with an arrow pointing to Ci; segment E1A1 is under segment D1A1; points T20 and X2o are linked by a black bold segment with an arrow pointing to X2o; points T2o and Y2o are linked by a black bold segment with an arrow pointing to Y20; points T20 and Z20 are linked by a colorful bold segment with an arrow pointing to Z20; points X2o and Z2o and points Y2o and Z20 are linked by black thin dotted segments respectively; k) The marks of the coordinate points:
Point A0 for " E0", point B0 for "£/', point C0 for "U",
point D0 for "0", point E0 for "Eq", point F0 for "M", and
point Go for "N";
Point Ai upper for "^", lower for nEd", point Ci for
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"U", point Di for "0", and point Ei for "ig";
Point A2 for "SJ)0", point B2 for "31)/', point C2 for "Z3P", point D2 for "0", and point E2 for "3I>";
Point A4 for "Bt0", point B4 for "St/', point C4 for "Z2i>", point D4 for "0", and point E4 for "3I>";
Point A5 for "E0", point C5 for "U", and point D5 for "0"; and
Points X20, Y20 and Z20 for "3^", "1%" and X" respectively;
The marks move with the moving of the positions of the coordinate points, and the relative positions of the marks and corresponding coordinate points keep constant;
1) The power angle marks: the dotted line representing the power angle passes through the center of the rotor, superposing the axial center of the lever, and being not longer than 1/3 of the length of segment CoD0 obtained when the synchronous motor is under rating operation; it is marked as "5" within the range of the power angle, the levers at both sides of the power angle are connected by an arc, the vertex of the arc varies as the positions of the levers vary, the radius of the arc is longer than the radius of the rotor rigid body circle, and the center of the arc superposes the stator axial center; m) The magnetic excitation adjustment signal marks: Two methods:
(a) In accordance with the abrupt change algorithm, depending on the length percentage by which AE0 takes the present magnetic excitation potential, when AE0 is greater than a given value it reveals the abrupt change of the magnetic excitation potential; when AE0 is positive, the adjustment signals are arranged from the top of the magnetic excitation lever to the rotor axial center, and
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when AE0 is negative, the adjustment signals are arranged from the rotor axial center along the reverse direction of the magnetic excitation potential; on the displaying screen the adjustment signals and their colors are marked;
(b) In accordance with the adjustment algorithm and the calculation results of the computer, by the values
F F F
of 01, °2 ... ^", the adjustments are represented with
different colors and arranged depending on the length percentages they take; the increment-adjustment signals are closely arranged from the top of the magnetic excitation lever to the rotor axial center in sequence, and the reduction-adjustment signals are linearly and closely arranged from the rotor axial center along the reverse direction of the magnetic excitation potential in sequence; on the displaying screen the adjustment signals and their colors are marked;
n) The PQ curve mark: determining the curve between points M0 and N0 according to the end heat-emitting limit of the synchronous motor and the greatest operation power angle of the synchronous motor that the system permits, determining the N0Oo curve according to the greatest active power that the synchronous motor permits, determining the O0P0 curve according to the greatest stator magnetic flux, the greatest stator current and the greatest stator potential that the synchronous motor permits, and determining the P0Q0 curve according to the greatest rotor magnetic flux, the greatest rotor current and the greatest rotor voltage that the synchronous motor permits; points M0 and Q0 are both on the line D0G0, and points G0 and Q0 are connected by a thin line; curve M0N000PoQo (exclusive of the linear segment M0Q0) is depicted by a bold real line, the color of which is determined according to the user's requirement;
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o) The composite magnetic leakage alarm circle: depicting a circle by taking T2o as the center of the circle and taking the greatest magnetic leakage flux that the synchronous motor permits as the radius; this circle is the alarm circle, which is represented by a colorful bold curve;
p) The synchronous image requirements: depicting dotted circles by taking point D5 as the center of the circle and taking segments D5A5 and D5C5 as the radius respectively;
q) The mechanical model may rotate anticlockwise dynamically, the ratio of the rotation speed of the model and that of the real object is marked on the screen, and the rotation speed ratio may be selected;
r) The image alarm display: when an alarm is given on electric parameters or magnetic flux, the marks turn to red flickers, the speaker of the computer whistles, and the corresponding segments in the composite power angle graph and its sub-figures and the end composite magnetic leakage graph turn to red flickers; and when the alarm is relieved, the alarm marks or segments stay red but without flicker;
s) In accordance with the afore-mentioned imaging requirements, the six graphs obtained through program process can be combined with each other according to the requirements of the user, and any one of the combined images can be further combined with the digital display image of Figure 11; adjustments may be made within a small range on the stator radius and rotor radius, the axial center radius of the stator and of the rotor, the diameter of the lever and the spring joint radius of the synchronous motor, which are given in the composite power angle graph and its sub-figures; the mechanical model graphs may be made as various three-dimensional mechanical
79

model graphs; and the color of the models may be adjusted according to the requirements of the user; The computing program process including: (1) Determination of the parameters
Given parameters: the leakage reactance " of the motor stator (Potier reactance), quadrature-axis
synchronous reactance q , synchronous motor voltage,
K K
current and frequency conversion coefficients u, ' and
ir
K K
xu and Xt», active and reactive power conversion
W K K
coefficients p, Q and m, the conversion coefficients
K K K
L, GL and BL of the magnetic excitation voltage and the
operating excitation voltage and backup excitation voltage
if
of the synchronous motor, the conversion coefficients f ,
K K
Gf and Bf of the magnetic excitation current and the
operating excitation current and backup excitation current of the synchronous motor, negative sequence voltage
IT
conversion coefficient F, the synchronous conversion
K K
coefficients T and N of the synchronous motor end
is
voltage, the synchronous conversion coefficients -"" and
K K
m of the system voltage, the conversion coefficient TJ
of the voltage of the magnetic excitation adjustment signal, and magnetic flux leakage coefficients K1, K2 and K3; allowable range of main parameters: main parameters comprise motor end voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux, power angle and system voltage; rating parameters of the motor mainly comprise: motor end

voltage, stator current, magnetic excitation voltage, magnetic excitation current, active power, reactive power, stator magnetic flux, rotor magnetic flux and system voltage;
(2) Calculation of the parameters a) Pj=KrP ZP = KmPj

b
Qj=KQQi ZQ = KmQj
c) Iaj=KlIa Ibj=KlIb Icj=KlIc
d) Uabj = KvUab t Uhcj = Kali* f UcaJ = KVUC
0 \ *f ~ &flL *Gf = ^GflG *Bf ~ *-BflBY
e / I I

f)
g)

P = K.f Fx = KxJx
UF] = KFUF

fa) Vxabj -^XU^xab " xbcj ~ ^ XU ^ xbc " xcaj ~ ^ XU ^ xca
j_) UU = KLUL UGj ~ KGLUG UBj = KBLUB
(3) Determination of the value of the direct-axis synchronous reactance Xd of the salient-pole synchronous motor
Two methods for determining the value of the direct-axis synchronous reactance Xd of the salient-pole synchronous motor are:
a) Directly determining the value of the direct-axis synchronous reactance Xd in accordance with the air gap potential E6 obtained when the synchronous motor is under normal operation, and the value of Xd being kept constant;
b) Determining the value of Xd through the value of Ee in accordance with the function relationship between the air gap potential E5 of the synchronous motor and the direct-axis synchronous reactance Xd, and comprising the steps of:
(a) Depicting the dynamotor zero load (ia =o )
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curve and the zero power factor (la = iN) curve, namely
curve U=jro(I/) and curve U=fN(If);
(b) Determining the function relationship between the air gap potential E5 of the synchronous motor and the direct-axis synchronous reactance Xd;
In accordance with the curves U=fo(I/) and U=fN(I/) , taking n magnetic excitation current values of
/1 , /2 ... r" , and determining on the curve U=fN(I/) points
Bi, B2 ... Bn corresponding to /1 , fl ... {n based on the zero power factor curve; Constructing n congruent triangles through points B, Bi, B2 ... Bn respectively (wherein segment CD is vertical to the I-coordinate, and CD = IN *Xa) ,
intersecting with the zero load characteristic curve of U= fo(If) at points C, Ci, C2, ... Cn respectively, connecting points 0 and Ci, and extending segment OC1 to intersect with the line that passes through point Bi and is parallel to the U-coordinate at point Ai; similarly, connecting points 0 and C2, ... connecting points 0 and Cn, and extending segment 0C2 ... extending 0Cn, and intersecting with the lines that pass through points B2 ... Bn respectively and are parallel to the U-coordinate at points A2 ... An respectively;
Therefore, the synchronous saturated reactance
F F F -^ i\ ~i—
corresponding to ■", S1 ... * respectively are: " ,
X =ML X =^L
dl 'N ... " 'N ; Depicting the relationship graph of
the air gap potential and the reactance in accordance with
F F F
the relationship between •" , sz ... Sn and respective
X X
corresponding synchronous saturated reactance Xj„

(c) Computing E5;

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Let W = P]+jQj=WZ Then '* = V(-*0,
Es=e+jiaJ*X„ . E, =|E,|
(d) Substituting the value of E5 into function Xd= f (E5) to obtain the value of Xd; (4) Calculations
. H =e+ jI*X= HZS
can be
s(90°)S)-90°)
determined by this equation /,, =IaJsin(S +

!q = Kj cos( a = (e * cos S + Id * X d) * cos 5
b = {e*cosS + Id * Xj)*smS

c = e + 1A

' cos S

d = IJ*XJ*sinS f = e * cos 2 S g = ye*sin 28
j) Calculations of components of the magnetic excitation
Two calculation methods are:
(a) Abrupt change algorithm
Assuming the average magnetic excitation potential of the synchronous motor during the period of AT from some certain time till now as SE0, and the current magnetic excitation potential being Eo; assuming AE0= E0-SE0; The value of AT and the times of sampling the magnetic excitation potential may be set;
(b) Adjustment algorithm
Assuming the total automatic magnetic excitation adjustment of the integrated amplifier as SU;

the components respectively are: TJ '

U' = KTJu2

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Af-KTJU, ■■■X-KTJU„. su= KTJ(Ui+U2+...+Un) , ^~ sV , ^ ~ *"'
f _ KTJU,

Calculating

= /, Va 2 + b 2 Em = /,-y/a2 + b>

£„„ = /„Va2+62
k) Calculation of coordinates of the magnetic flux leakage
Xx=Kia; Yi= Kxb; X2=K2 (f-a)+K3 (c-a) ; Y2=K2 (g-b) +K3 (d-b); X3=X!+X2; Y3=Y!+Y2
1) Calculation of the per-unit value of the magnetic flux: assuming when the frequency is at the rating value, the per-unit value of a certain magnetic flux of the synchronous motor equals to the per-unit value of the corresponding voltage; determining the per-unit values of the magnetic excitation flux and the stator total magnetic flux of the motor according to the relationship among frequency, voltage and magnetic flux, and displaying the per-unit values with digitals; comparing the calculated values with the given values, and alarming when the calculated values are larger than the given values;
m) Calculations of the per-unit values of various parameters according to the requirements;
(5) During the synchronous parallel-network or
parallel-off, namely when /aj U = KT(uAB +uBCZ\20" +uCAZ240°) = UZa
(b) U, = KXT(uXAB+uXBCZl20° + uXCAZ2400) = UxZE
JL = JLZ5
(c) u-
§ _ sl+s1+-s„
(d) * " (wherein ' 2 " are the values of
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the first, the second ... and the n s„ measured within a certain time period; when a second measured value enters, the value of the first 5« is abandoned, and when the next
measured value enters, the value of the second °i is abandoned; analogically, the new measured values replace the old ones; and the time period and the value of n can be set.)
(e) h = KHU^*cosS,
(g) J = K™U'*i (6) Comparing various electric parameters with respective given values, and alarming when the electric parameters are out of the prescribed ranges.
4. A method for measuring the operating state of synchronous motor substantially such as herein described with reference to accompanying drawings.
m*
Dated this 01st day of July 2006
MAHUA GHOSH
OF K & S PARTNERS
AGENT FOR THE APPLICANT(S)
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Abstract
The present invention discloses a method for measuring the operating state of synchronous motor by using composite power angle meter, the method comprising steps of: a) obtaining various signals of the synchronous motor and its system; b) converting the electric signals into digital signals by an internal data collection part of the composite power angle meter, and inputting all the digital signals to a host computer; c) inputting related parameters or commands to the host computer by keyboard and mouse; d) calculating the related data of the motor according to a program by the host computer, obtaining the coordinates of relevant points and related data, and inputting the results to a displaying program; e) processing the coordinates of main points and the calculation results by the displaying program in the host computer, and displaying on a display a dynamic composite power angle graph and the motor-end composite magnetic leakage graph which vary with the motor's parameters. The method provided by the present invention may intuitionally reflect the operating state of the synchronous motor from both electric and mechanical aspects, and also reflect the situation of the composite magnetic leakage at the synchronous motor end.
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Patent Number 225910
Indian Patent Application Number 782/MUMNP/2006
PG Journal Number 07/2009
Publication Date 13-Feb-2009
Grant Date 03-Dec-2008
Date of Filing 05-Jul-2006
Name of Patentee WANG,ZHAOLEI
Applicant Address Operating Department,Qin Bei Power Of Huaneng,Wulongkou County, 454662 Jiyuan City, Henan Province,
Inventors:
# Inventor's Name Inventor's Address
1 WANG,ZHAOLE Operating Department,Qin Bei Power Of Huaneng,Wulongkou County,454662 Jiyuan City,Henan Province.
2 HUA,Zexi Operating Department,Qin Bei Power Of Huaneng,Wulongkou County,454662 Jiyuan City,Henan Province,China
PCT International Classification Number G01R31/34,G01R25/00
PCT International Application Number PCT/CN2003/001153
PCT International Filing date 2003-12-31
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 China 2003-12-31 China