| Title of Invention | ELEVATOR DRIVING INVERTER SYSTEM WITHOUT ELECTROLYTIC CAPACITOR |
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| Abstract | Disclosed is an elevator driving inverter system without an electrolytic capacitor, which uses a new type converter circuit so as to allow a high-capacity electrolytic capacitor to be removed from a whole system so that an initial charge circuit becomes unnecessary, a DC REACTOR and damping resistance are removed, and a 4 Quadrant AC motor control system for regenerating energy can be also implemented. As a result, it is possible to implement a cheaper elevator driving system, which can achieve high efficiency and size-reduction. The elevator driving inverter system without an electrolytic capacitor, which drives an alternating current (AC) motor by means of an inverter after obtaining continuous current (DC) power from a three-phase input power of a power unit, includes a filter unit for decreasing harmonic element of current, the filter unit being included in the power unit; and a pair of three-phase converter connected between the filter unit and a motor unit for driving the AC motor in parallel, wherein a input side circuit of a power includes a two-way rectifier circuit, and an output side circuit of the power includes a voltage type inverter so that power from the power unit is transferred to the motor unit by means of a diode, and energy from the motor unit is transferred by means of an active switch so as to be regenerated as power. |
| Full Text | FORM 2 THE PATENT ACT 197 0 (39 of 1970) & The Patents Rules, 2 0 03 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION ELEVATOR DRIVING INVERTER SYSTEM WITHOUT ELECTROLYTIC CAPACITOR 2. APPLICANT(S) a) Name b) Nationality c) Address : HYUNDAI ELEVATOR CO., LTD. : KOREAN Company : SAN 136-1 AMI-RI, BUBAL-EUP ICHON-SHI, KYONGGI-DO 467-734 KOREA 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to an elevator driving inverter system without an electrolytic capacitor, and more particularly to an elevator driving inverter system without an electrolytic capacitor, which uses a new type of converter circuit so as to allow a high-capacity electrolytic capacitor to be removed from a conventional system so that an initial charge circuit becomes unnecessary, a DC reactor and damping resistance are removed, and a 4 Quadrant AC motor control system capable of regenerating energy can be also implemented. 2. Description of* the Prior Art In general, as shown in FIG. 1, a control system of a conventional elevator alternating current (AC) motor uses a method for driving a motor unit 40 of an electric motor by using an inverter 30 after converting AC power from a power unit 10 to direct current (DC) power by using a three-phase diode rectifier circuit 20. At this time, since energy cannot regenerated due to a characteristic of a diode rectifier circuit, the method as described above requires a damping resistance 50. Meanwhile, in order to absorb instantaneous energy regenerated in the inverter 30, a high-capacity electrolytic capacitor 60 as a reactive energy storing element is used in a DC link. However, the electrolytic capacitor 60 has a problem regarding its life aspen, as well as a problem of increasing harmonics of current of an input side of power. Also, there is a problem in that an initial charging circuit 70 is necessarily accompanied so as to suppress initial charge current. Also, because of employment of the initial charging circuit 70, the cost of a product increases and reliability decreases. Also, a DC reactor used for suppressing harmonics of current has a problem of voltage drop and a problem of lowering inverter efficiency. SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and the present invention provides an elevator driving inverter system without an electrolytic capacitor, which uses a new type of converter circuit so as to allow a high-capacity electrolytic capacitor to be removed from a conventional system so that an initial charge circuit becomes unnecessary, a DC REACTOR and damping resistance are removed, and a 4 Quadrant AC motor control system for regenerating energy can be also implemented. In accordance with an aspect of the present invention, there is provided an elevator driving inverter system without an electrolytic capacitor, which drives an alternating current (AC) motor by means of an inverter after obtaining continuous current (DC) power from a three-phase input power of a power unit, the elevator driving inverter system including: a filter unit for decreasing harmonic element of current, the filter unit being included in the power unit; and a pair of three-phase converters connected between the filter unit and a motor unit for driving the AC motor in parallel, wherein an input side circuit of a power includes a two-way rectifier circuit, and an output side circuit of the power includes a voltage type inverter so that power from the power unit is transferred to the motor unit by means of diode, and energy from the motor unit is transferred by means of an active switch so as to be regenerated as power. It is preferable that an auxiliary diode rectifier for measuring voltage of power so as to generate a switch signal is included in the output side of the power unit. It is preferable that a small capacity snubber capacitor for suppressing spark type voltage variation of DC-Link voltage is included in an output side of the two-way rectifier circuit. According to the present invention as described above, a high-capacity electrolytic capacitor can be removed from an elevator motor driving system due to employment of a converter circuit including a two-way rectifier circuit. Therefore, an initial charging circuit can be made unnecessary, and a DC reactor and damping resistances can be removed. Also, it is possible to provide a 4 Quadrant AC motor control system which can regenerate energy. As a result, high efficiency, size-reduction, low price, etc. of the elevator driving system can be achieved. Also, the system has very useful efficiency so that it can be applied to a motor driving system used in various fields, such as air conditioners and refrigerators in homes, cooling and heating HVAC Systems used in office buildings, industrial robots and equipment for factory automatization in industrial fields, cranes, electromotive vehicles, high-speed railways, etc. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a circuit diagram showing a control system of a conventional AC motor of an elevator; FIG. 2 is a circuit diagram showing an elevator driving inverter system without an electrolytic capacitor according to the present invention; FIG. 3 is a graph showing a switching waveform of a two-way rectifier circuit included in an AC/DC converter in an elevator driving inverter system without an electrolytic capacitor according to the present invention; FIGs. 4a and 4b are circuit diagrams showing a operational state of a two-way rectifier circuit according to a sensing signal of an auxiliary diode rectifier in an elevator driving inverter system without an electrolytic capacitor according to the present invention; and FIG. 5 is a circuit diagram showing an equivalent circuit of a two-way rectifier circuit included in an AC/DC converter in an elevator driving inverter system without an electrolytic capacitor according to the present invention, DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS Hereinafter, an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a circuit diagram showing an elevator driving inverter system without an electrolytic capacitor according to the present invention and FIG. 3 is a graph showing a switching waveform of a two-way rectifier circuit included in an AC/DC converter in an elevator driving inverter system without an electrolytic capacitor according to the present invention. Also, FIGs. 4a and 4b are circuit diagrams showing a operational state of a two-way rectifier circuit according to a sensing signal of an auxiliary diode rectifier in an elevator driving inverter system without an electrolytic capacitor according to the present invention and FIG. 5 is a circuit diagram showing an equivalent circuit of a two-way rectifier circuit included in an AC/DC converter in an elevator driving inverter system without an electrolytic capacitor according to the present invention. Firstly, the elevator driving inverter system without an electrolytic capacitor according to the present invention includes: a power unit 100, to which three-phase input power is inputted; a filter unit 200 for filtering the three-phase input power of the power unit 100; a pair of three-phase converters 300 and 400 connected with the filter unit 200; and an auxiliary diode rectifier 600, which measures output voltage of the power unit 100 so as to generate a switching signal. Therefore, power from the power unit 100 is delivered to a motor unit 500 by means of a diode so as to drive an electric motor. Also, when the elevator performs a regenerative operation, energy of the motor unit 500 of the electric motor is regenerated as a power by means of an active switch. That is, the power unit 100 supplies three-phase input power from the outside to the system. The filter unit 200 is included in an output side of the power unit 100 so as to decrease a harmonic component of current. Also, the pair of three-phase converters includes a two-way rectifier circuit 300 and a voltage type inverter 400. The two-way rectifier circuit 300 selectively switches power, which is filtered through the filter unit 200 and is outputted, according to a switching signal of the auxiliary diode rectifier 600, so as to output the power to the motor unit 500 by means of the inverter 400. Also, the two-way rectifier circuit 300, which is included in the three-phase converters, includes an Insulated Gate Bipolar Transistor (IGBT). Therefore, the two-way rectifier circuit 300 transfers energy, which is generated according to driving of the motor unit 500 of the electric motor of the elevator, by means of the IGBT so as to allow the energy to be regenerated as power. That is, the auxiliary diode rectifier 600 included in the output side of the power unit 100 measures voltage of the power unit 100 and generates a sensing signal. Then, the auxiliary diode rectifier 600 transfers the signal to the two-way rectifier circuit 300 so as to apply a control signal, which allows power from the power unit 100 to be transferred to the motor unit 500 or allows energy from the motor unit 500 to be regenerated. Also, a small capacity snubber capacitor 310 is included in an output side of the two-way rectifier circuit 300. The small capacity snubber capacitor 310 plays the role of suppressing spark-type voltage variation of DC-Link voltage. Subsequently, operation of the present invention, which is structured as described above, will be described in detail with reference to FIGs. 2 to 5. Firstly, while the active switch (IGBT) of the two-way rectifier circuit 300 is selectively controlled according to a sensing signal from an auxiliary diode rectifier 600 connected with an output side of the power unit 100, the elevator driving inverter system without an electrolytic capacitor according to the present invention performs motoring operation for transferring power of the power unit 100 to the motor unit 500 of the electric motor of the elevator or performs a generation operation for allowing energy of the motor unit 500 to be regenerated as power. That is, in the auxiliary diode rectifier 600, an input diode of a photocoupler is conducted together with each diode at a time point when each diode is conducted. As a result, a signal generated as each diode of the diode rectifier is conducted is shown through output of the photocoupler. This signal is used as a switching signal of the two-way rectifier circuit 300. At this time, as shown in FIG. 3, a switch of the two-way rectifier circuit 300, which is included in the AC/DC converter, is turned on/off according to conduction of the three-phase diode rectifier connected with the same three-phase power. In FIG.3, (a) shows power voltage, (b) shows A-phase upper switch, and (c) shows A-phase upper and lower end switch. Meanwhile, the operation of the two-way rectifier circuit 300 according to a sensing signal of the auxiliary diode rectifier 600 will be illustrated with reference to FIGs. 4a and 4b. Switch numbers of respective gates of IGBT included in the two-way rectifier circuit 300 are number 1 to number 6. These gate switch numbers make each pair of number 1 and number 4, number 2 and number 5, and number 3 and number 6. Moreover, the pair of gate switch number 1 and number 4, the pair of number 2 and number 5, and the pair of number 3 and number 6 are connected while corresponding to three-phase input power Ea, Eb, and Ec supplied from the power unit 100. Then, a predetermined sensing signal is applied to these gate switches through the auxiliary diode rectifier 600. That is, as shown in FIG. 4a, in a case where a sensing value of power Ea of the power unit is plus (+) value, the two-way rectifier circuit 300 is controlled according to a sensing signal of the auxiliary diode rectifier 600 so as to allow the gate switch of number 1 to be turned on so that the two-way rectifier circuit 300 is operated together with the three-phase diode rectifier so as to transfer power of the power unit 100 to the motor unit 500 of the electric motor of the elevator. Accordingly, a motoring operation is performed. Meanwhile, as shown in FIG. 4b, in a case where a sensing value of power Ea of the power unit 100 is a minus (-) value, the two-way rectifier circuit 300, which is constituted of IGBT, is controlled according to a sensing signal of the auxiliary diode rectifier 600 so as to allow the gate switch of number 4 to be turned on so that a generating operation of allowing energy of the motor unit 500 to be regenerated in the power unit 100 is performed. At this time, in the operation of the two-way rectifier circuit 300 performing the AC/DC converter function, as shown in FIG. 5, it is possible to form an equivalent circuit having six ripples in a single time period of the input power. Meanwhile, power Eb and power Ec, which are other three-phase input power of the power unit 100, are controlled by a scheme for controlling power Ea, which is described above. That is, according to a sensing signal of the auxiliary diode rectifier 600, the switches of gate numbers 2 and 3, and the switches of gate numbers 5 and 6 are selectively turned on so that the motoring operation or the generating operation is performed. Therefore, as described above, when regeneration operation of the elevator is performed, it is possible to regenerate energy in the power unit 100 through the two-way rectifier circuit 300 constituted of IGBT. As a resu1t it is possible to remove a high-capacity electrolytic capacitor, which is necessary in order to absorb instantaneous energy regenerated in the damping resistance inverter for consuming regeneration energy in the conventional three-phase diode rectifier circuit incapable of regenerating energy. Meanwhile, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. WE CLAIM: 1. An elevator driving inverter system without an electrolytic capacitor, which drives an alternating current (AC) motor by means of an inverter after obtaining continuous current (DC) power from a three-phase input power of a power unit, the elevator driving inverter system comprising: a filter unit for decreasing harmonic element of current, the filter unit being included in the power unit; and a pair of three-phase converters connected between the filter unit and a motor unit for driving the AC motor in parallel, wherein an input side circuit of a power includes a two-way rectifier circuit and an output side circuit of the power includes a voltage type inverter so that power from the power unit is transferred to the motor unit by means of diode, and energy from the motor unit is transferred by means of an active switch so as to be regenerated as power. 2. The elevator driving inverter system as claimed in a claim 1, wherein an auxiliary diode rectifier for measuring voltage of power so as to generate a switch signal is included in the output side of the power unit. 3. The elevator driving inverter system as claimed in claim 1, wherein a small capacity snubber capacitor for suppressing spark type voltage variation of DC-Link voltage is included in an output side of the two-way rectifier circuit. Dated this 20th day of October, 2008 |
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2259-MUM-2008-ABSTRACT(23-10-2013).pdf
2259-MUM-2008-CLAIMS(AMENDED)-(23-10-2013).pdf
2259-MUM-2008-CORRESPONDENCE(18-12-2008).pdf
2259-MUM-2008-CORRESPONDENCE(22-10-2013).pdf
2259-MUM-2008-CORRESPONDENCE(3-11-2008).pdf
2259-MUM-2008-CORRESPONDENCE(31-12-2012).pdf
2259-mum-2008-correspondence.pdf
2259-mum-2008-description(complete).doc
2259-mum-2008-description(complete).pdf
2259-mum-2008-english translation.pdf
2259-MUM-2008-FORM 1(18-12-2008).pdf
2259-mum-2008-form 2(title page).pdf
2259-MUM-2008-FORM 3(22-10-2013).pdf
2259-MUM-2008-GENERAL POWER OF ATTORNEY(23-10-2013).pdf
2259-MUM-2008-GENERAL POWER OF ATTORNEY(3-11-2008).pdf
2259-MUM-2008-MARKED COPY(23-10-2013).pdf
2259-MUM-2008-OTHER DOCUMENT(23-10-2013).pdf
2259-MUM-2008-PETITION UNDER RULE-137(22-10-2013).pdf
2259-MUM-2008-REPLY TO EXAMINATION REPORT(23-10-2013).pdf
2259-MUM-2008-SPECIFICATION(AMENDED)-(23-10-2013).pdf
| Patent Number | 260574 | |||||||||
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| Indian Patent Application Number | 2259/MUM/2008 | |||||||||
| PG Journal Number | 19/2014 | |||||||||
| Publication Date | 09-May-2014 | |||||||||
| Grant Date | 08-May-2014 | |||||||||
| Date of Filing | 20-Oct-2008 | |||||||||
| Name of Patentee | HYUNDAI ELEVATOR CO., LTD. | |||||||||
| Applicant Address | SAN 136-1 AMI-RI,BUBAL-EUP ICHON-SHI,KYONGGI-DO | |||||||||
Inventors:
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| PCT International Classification Number | B66B1/00 | |||||||||
| PCT International Application Number | N/A | |||||||||
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PCT Conventions:
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