Title of Invention	AN INDUCTION MOTOR RECEIVING A FLUCTUATING INPUT SUPPLY VOLTAGE, YET PROVIDING SUBSTANTIALLY THE SAME RATED POWER OUTPUT
Abstract	1. An induction motor, receivinq a f1urtuating input supply voltage, yet providing substantially the same rateed power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output.

Title of Invention

AN INDUCTION MOTOR RECEIVING A FLUCTUATING INPUT SUPPLY VOLTAGE, YET PROVIDING SUBSTANTIALLY THE SAME RATED POWER OUTPUT

Abstract

1. An induction motor, receivinq a f1urtuating input supply voltage, yet providing substantially the same rateed power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output.

Full Text	This invention relates to an induction motor receiving a fluctuating input supply voltage, yet providing substantially the same rated power output. Substantially the same rated power output becomes possible since the equation Power is proportional to V.l (P VI) has two compensating variables V and I. (For a three phase induction motor, Power =• V.3.V.J. oosO) This invention is applicable to single phase as well as to multi-phase induction motprs. A normal induction motor is designed for a specific supply voltage, also called the rated supply voltage. The motor can satisfactorily operate within a variation (fluctuation) margin e.g. plus or minus 5% of the rated input voltage without noticeably affecting the power output. When the input voltage falls below, or rises above, the rated voltage, beyond the margin, the current: increases drastically, and the power output, as well as the efficiency, drop considerably. mis invention, accordingly, proposes an induction motor which, although, receiving a fluctuating input; supply Voltage, yet provides substantially the same rated power output. Some of the advantages of this invention are: * Coil burnouts due to voltage fluctuations can be minimised * The motor is optimally loaded * Reduced heating of the stator * Higher efficiency and power factor under varying voltage conditions * Easier starting under low voltage conditions. Various other advantages of this invention will be apparent from the following further description thereof. According to this invention, the induction motor although receiving a fluctuating input supply vol I age, yet providing substantially the same rated power output, comprises a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in a predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output. If the cross-sectional area of the winding conductor of the standard induction motor is C, it is preferred to have the cross-sectional area of each of the strands N a fraction of C so that the total cross-sectional area of all the strands substantially equals C. * This invention will now be described with reference to the accompanying drawings in which its salient features and one of possible embodiments thereof are illustrated, by way of example and not by way of limitation. In the drawings Fig. 1 illustrates the phase winding of a normal induction motor Fig..2 illustrates the phase windinq of the induction motor proposed herein Fig. 3 illustrates four input supply voltage values Va, Vb, Vc, Vd; corresponding current density curves la,.Ib,lc and Id. Fig. 4 illustrates the layout diagram of one of possible embodiments of the the induction motor proposed herein including the sensing and switching means. As stated earlier, the motor can comfortably operate at a supply voltage band width of around 5?. plus or minus of the rated input supply voltage. Fig. 1 illustrates the winding of a single phase in a standard induction motor. In the proposed induction motor the winding (Fig.2) of a single phase consists of 4 strands S corresponding to the 4 bands of fluctuating input supply voltage values. Sensing means are provided for sensing the input supply voltage, such as, an electrical sensor e.g. a voltmeter system, an electronic sensor system or a microprocessor system A connected to the input lines of the motor M for sensing the input Supply voltage. Switching means (such as an electrical contactor system, a mult ipole-multiposition switch or an electronic switching system B) are provided for being activated by the sensing means, whenever' the input supply voltage fluctuates from the rated value and falls in one of the four bands. On activation, the said switching means connect the said 4 strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input, supply voltage. This predetermined number of turns is the number required for producing substantially the same rated power output. Thus, if the voltage fluctuation is of a value falling between Va and Vb, the microprocessor A senses the value and activates the switching means B. Once activated, the switching means B connects the strands S of the winding to obtain a predetermined number of turns required to furnish substantially the same rated power output: . The above operation can also be carried out manually. Thus, if the voltage fluctuation is of a value falling between Va and Vb, a voltmeter (used as sensing means) senses the value. The Operator viewing a prepared chart manually activates the multipole - multiposition switch R (used as switching means). Once activated, the switching means B connects the strands' S of the winding to obtain a predetermined number of turns required to furnish substantially the same rated power output. The predetermined relationship of the said strands comprises connection thereof in series, parallel, series-parallel relationship. The terms and expressions in (his specification are of description and not of limitation, there heinq no intention to exclude any equivalents of the features thereof, but it-is understood that various other embodiments of the induction motor proposed herein are possible without departing from the scope and ambit of this invention. I claim: 1. An induction motor, receivinq a f1urtuating input supply voltage, yet providing substantially the same rateed power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output. 2. An induction motor as claimed in Claim 1 wherein the cross-sectional area of each of the N strands is a fraction of the cross-sectional area of the conductor of the winding of the corresponding known induction motor so that the sum total of the cross-sectional areas of the N strands substantially equals the cross-sectional area of the said conductor. 3. An induction motor as- claimed in any one of the preceding Claims,1 AND 2 wherein the sensing means comprise an electronic sensor system for sensing the input supply voltage. 4. An induction motor as claimed in any one of the preceding Claims 1 and 2 wherein the sensing means comprise an electrical sensor system for sensing t:he i npnj I supply voltage. 5. An induction motor as claimed in any one of the preceding Claims 1 and 2 wherejn the sensing means comprise a microprocessor for sensing fhe input supply vollage. 6. An induction motor as claimed in anyone of the preceding/Claims wherein the sw.i fching means comprises of an electrical switching system. 7. An induction motor as claimed in any one of the preceding Claims 1 to 5 wherein fhe switching means comprises of an electronic switching system. 8. An induction motor as claimed in any one of the preceding Claims 1 to 5 wherein the switching means comprises of a manual switching system. 9. An induction motor as claimed in any one of the preceding , Claims/wherein the predetermined reLationship of the said strands comprises connection thereof In series, parallel, series-parallel relationship. 10. An induction motor as claimed in any one of the preceding Claims^provided with a single phase winding. 11. An induction motor as claimed in any on^ .if preredir\g Claims 1 to 9 provided with a mult.i-phase winding. 12. An induction motor receiving a fluctuating input supply voltage, yet providing sut)Stant-ially the same raled power output, substantially as herein described

Full Text

This invention relates to an induction motor receiving a
fluctuating input supply voltage, yet providing
substantially the same rated power output.
Substantially the same rated power output becomes possible
since the equation Power is proportional to V.l (P VI)
has two compensating variables V and I. (For a three phase
induction motor, Power =• V.3.V.J. oosO)
This invention is applicable to single phase as well as to
multi-phase induction motprs.
A normal induction motor is designed for a specific supply
voltage, also called the rated supply voltage. The motor
can satisfactorily operate within a variation (fluctuation)
margin e.g. plus or minus 5% of the rated input voltage
without noticeably affecting the power output.
When the input voltage falls below, or rises above, the
rated voltage, beyond the margin, the current: increases
drastically, and the power output, as well as the
efficiency, drop considerably.

mis invention, accordingly, proposes an induction motor which, although, receiving a fluctuating input; supply Voltage, yet provides substantially the same rated power output. Some of the advantages of this invention are:
* Coil burnouts due to voltage fluctuations can be minimised
* The motor is optimally loaded
* Reduced heating of the stator
* Higher efficiency and power factor under varying voltage conditions
* Easier starting under low voltage conditions.
Various other advantages of this invention will be apparent from the following further description thereof. According to this invention, the induction motor although receiving a fluctuating input supply vol I age, yet providing substantially the same rated power output,

comprises a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in a predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output.
If the cross-sectional area of the winding conductor of the standard induction motor is C, it is preferred to have the cross-sectional area of each of the strands N a fraction of C so that the total cross-sectional area of all the strands substantially equals C.
*
This invention will now be described with reference to the accompanying drawings in which its salient features and one of possible embodiments thereof are illustrated, by way of example and not by way of limitation.

In the drawings
Fig. 1 illustrates the phase winding of a normal induction
motor
Fig..2 illustrates the phase windinq of the induction motor
proposed herein
Fig. 3 illustrates four input supply voltage values Va, Vb,
Vc, Vd; corresponding current density curves la,.Ib,lc and
Id.
Fig. 4 illustrates the layout diagram of one of possible
embodiments of the the induction motor proposed herein
including the sensing and switching means.
As stated earlier, the motor can comfortably operate at a supply voltage band width of around 5?. plus or minus of the rated input supply voltage.
Fig. 1 illustrates the winding of a single phase in a standard induction motor.

In the proposed induction motor the winding (Fig.2) of a single phase consists of 4 strands S corresponding to the 4 bands of fluctuating input supply voltage values. Sensing means are provided for sensing the input supply voltage, such as, an electrical sensor e.g. a voltmeter system, an electronic sensor system or a microprocessor system A connected to the input lines of the motor M for sensing the input Supply voltage.
Switching means (such as an electrical contactor system, a mult ipole-multiposition switch or an electronic switching system B) are provided for being activated by the sensing means, whenever' the input supply voltage fluctuates from the rated value and falls in one of the four bands. On activation, the said switching means connect the said 4 strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input, supply voltage. This predetermined number of turns is the

number required for producing substantially the same rated power output.
Thus, if the voltage fluctuation is of a value falling between Va and Vb, the microprocessor A senses the value and activates the switching means B. Once activated, the switching means B connects the strands S of the winding to obtain a predetermined number of turns required to furnish substantially the same rated power output: .
The above operation can also be carried out manually. Thus, if the voltage fluctuation is of a value falling between Va and Vb, a voltmeter (used as sensing means) senses the value. The Operator viewing a prepared chart manually activates the multipole - multiposition switch R (used as switching means). Once activated, the switching means B connects the strands' S of the winding to obtain a predetermined number of turns required to furnish substantially the same rated power output. The predetermined relationship of the said strands

comprises connection thereof in series, parallel, series-parallel relationship.
The terms and expressions in (his specification are of description and not of limitation, there heinq no intention to exclude any equivalents of the features thereof, but it-is understood that various other embodiments of the induction motor proposed herein are possible without departing from the scope and ambit of this invention.

I claim:
1. An induction motor, receivinq a f1urtuating input supply voltage, yet providing substantially the same rateed power output, comprising a stator coil winding of N strands per phase; sensing means for sensing the input supply voltage; switching means which, whenever activated by the sensing means on sensing an input supply voltage fluctuation from the rated value to a value falling in one of N bands, connects the said strands together in predetermined relationship, to present a predetermined number of turns of the said winding to the input supply voltage, thus providing substantially the same rated power output.
2. An induction motor as claimed in Claim 1 wherein the cross-sectional area of each of the N strands is a fraction of the cross-sectional area of the conductor of the winding of the corresponding known induction motor so that the sum total of the cross-sectional areas of the N strands substantially equals the cross-sectional area of the said conductor.

3. An induction motor as- claimed in any one of the

preceding Claims,1 AND 2 wherein the sensing means comprise an electronic sensor system for sensing the input supply voltage.
4. An induction motor as claimed in any one of the preceding Claims 1 and 2 wherein the sensing means comprise an electrical sensor system for sensing t:he i npnj I supply voltage.
5. An induction motor as claimed in any one of the preceding Claims 1 and 2 wherejn the sensing means comprise a microprocessor for sensing fhe input supply vollage.
6. An induction motor as claimed in anyone of the preceding/Claims wherein the sw.i fching means comprises of an electrical switching system.
7. An induction motor as claimed in any one of the preceding Claims 1 to 5 wherein fhe switching means comprises of an electronic switching system.

8. An induction motor as claimed in any one of the preceding
Claims 1 to 5 wherein the switching means comprises of a
manual switching system.
9. An induction motor as claimed in any one of the preceding , Claims/wherein the predetermined reLationship of the said strands comprises connection thereof In series, parallel, series-parallel relationship.
10. An induction motor as claimed in any one of the preceding Claims^provided with a single phase winding.
11. An induction motor as claimed in any on^ .if preredir\g Claims 1 to 9 provided with a mult.i-phase winding.
12. An induction motor receiving a fluctuating input supply voltage, yet providing sut)Stant-ially the same raled power output, substantially as herein described

Documents:

226-mas-2002 claims duplicate.pdf

226-mas-2002 claims.pdf

226-mas-2002 correspondence-other.pdf

226-mas-2002 correspondence-po.pdf

226-mas-2002 description (complete) duplicate.pdf

226-mas-2002 description (complete).pdf

226-mas-2002 drawings.pdf

226-mas-2002 form-1.pdf

226-mas-2002 form-19.pdf

226-mas-2002 form-26.pdf

226-mas-2002 form-5.pdf

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Patent Number

202130

Indian Patent Application Number

226/MAS/2002

PG Journal Number

30/2009

Publication Date

24-Jul-2009

Grant Date

Date of Filing

28-Mar-2002

Name of Patentee

DAMAYANTI RAMACHANDRAN,

Applicant Address

20 A.T.D. STREET, RACE COURSE, COIMBATORE 641 018

Inventors:

#	Inventor's Name	Inventor's Address
1	PREM SHANKER,	TEXMO INDUSTRIES, METTUPALAYAM ROAD, COIMBATORE 641029

PCT International Classification Number

H02K01/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA