Patent EP0410574A2 successfully refreshed from Google Patents.
EP0410574A2
Expired / Lapsed
EP
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Adjustable AC power supply equipment for air-conditioner system
Assignee: Toshiba Corp
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Filing: 1990-06-20
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Granted: —
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Expires: 2010-06-20
Abstract
Abstract In an adjustable a.c. power supply for an air-conditioner system, comprising a first frequency converter 9A for driving a compressor motor 6A of a first air-conditioner 7A, a second frequency converter 9B for driving a compressor motor 6B of a second air-conditioner 7B, and a common a.c. power supply 2 for delivering an a.c. power to the both frequency converters, a rectifier 3B included in at least one frequency converter 9B is constructed as a controllable rectifier and the rectifier 3B included in the second frequency converter 9B is subjected to phase-control so that a synthetic higher harmonic current of the two frequency converters when viewed from the a.c. power supply is reduced. By conducting a phase-control of the rectifiers in a manner that, e.g., one rectifier 3A has a phase-control angle of zero degrees and the other rectifier 3B has a phase-control angle of 30 degrees, a load current from the a.c. power supply 2 is permitted to have a waveform closer to a sine wave, i.e., a waveform in which higher harmonic components are further reduced.
Inventors
- 👤 Hidetoshi Kanazawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 19:13
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/40; H02M5/42; H02M5/44; H02M5/453; H02M5/458; H02M1/00; H02M1/12; F; F25; F25B; F25B2400/00; F25B2400/06; F25B2600/00; F25B2600/02; F25B2600/021; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: a first frequency converter comprised of a three-phase non-controllable rectifier and a first inverter to deliver a load current to a compressor motor of a first air-conditioner, a second frequency converter comprised of a three-phase controllable rectifier and a second inverter to deliver a load current to a compressor motor of a second air-conditioner, a common a.c. power supply for delivering an a.c. power to said both frequency converters, first and second means for controlling said first and second inverters, respectively, and third means for carrying out a phase-control of said rectifier of said second frequency converter in order to reduce a synthetic higher harmonic current of said both frequency converters when viewed from said a.c. power supply.
Claim 2
Dependent Claim
129 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: a first frequency converter comprised of a three-phase non-controllable rectifier and a first inverter to deliver a load current to a compressor motor of a first air-conditioner, a second frequency converter comprised of a three-phase controllable rectifier and a second inverter to deliver a load current to a compressor motor of a second air-conditioner, a common a.c. power supply for delivering an a.c. power to said both frequency converters, first and second means for controlling said first and second inverters, respectively, and third means for carrying out a phase-control of said rectifier of said second frequency converter in order to reduce a synthetic higher harmonic current of said both frequency converters when viewed from said a.c. power supply.
Claim 3
Dependent Claim
34 words
An adjustable a.c. power supply equipment as set forth in claim 1, wherein said higher harmonic reduction means controls said rectifier of said second frequency converter at a phase-control angle of substantially 30 degrees.
Claim 4
Dependent Claim
43 words
An adjustable a.c. power supply equipment as set forth in claim 1, wherein said inverter of said first frequency converter is constructed as a LC-less inverter, and said inverter of said second frequency converter is constructed as a capacitor input voltage type inverter.
Claim 5
Dependent Claim
171 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: a first frequency converter comprised of a three-phase non-controllable rectifier and a first inverter to deliver a load current to a compressor motor of a first air-conditioner, a second frequency converter comprised of a three-phase controllable rectifier and a second inverter to deliver a load current to a compressor motor of a second air-conditioner, a common a.c. power supply for delivering an a.c. power to said both frequency converters, first and second means for controlling said first and second inverters, respectively, third means for controlling said controllable rectifier of said second frequency converter, and fourth means for operating said controllable rectifier of said second frequency converter at a phase-control angle of zero degrees in an ordinary state, wherein when said fourth means receives a higher harmonic reduction command, said fourth means shifts the phase-control angle of said controllable rectifier so that a synthetic higher harmonic current of said both frequency converters when viewed from said a.c. power supply is reduced.
Claim 6
Dependent Claim
171 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: a first frequency converter comprised of a three-phase non-controllable rectifier and a first inverter to deliver a load current to a compressor motor of a first air-conditioner, a second frequency converter comprised of a three-phase controllable rectifier and a second inverter to deliver a load current to a compressor motor of a second air-conditioner, a common a.c. power supply for delivering an a.c. power to said both frequency converters, first and second means for controlling said first and second inverters, respectively, third means for controlling said controllable rectifier of said second frequency converter, and fourth means for operating said controllable rectifier of said second frequency converter at a phase-control angle of zero degrees in an ordinary state, wherein when said fourth means receives a higher harmonic reduction command, said fourth means shifts the phase-control angle of said controllable rectifier so that a synthetic higher harmonic current of said both frequency converters when viewed from said a.c. power supply is reduced.
Claim 7
Dependent Claim
31 words
An adjustable a.c. power supply equipment as set forth in claim 4, wherein a quantity of shift of the phase-control angle of said controllable rectifier is equal to substantially 30 degrees.
Claim 8
Dependent Claim
89 words
An adjustable a.c. power supply equipment as set forth in claim 4, which further comprises means for controlling a ratio V/f between an output voltage V and an output frequency f of said each inverter so that it is kept substantially constant in an ordinary state, wherein when said control means receives said higher harmonic reduction command, said control means steps up an output voltage V of said inverter of said second frequency converter in accordance with a phase-control angle of said controllable rectifier of said second frequency converter.
Claim 9
Dependent Claim
158 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: three sets of frequency converters each comprised of a three-phase controllable rectifier and an inverter to deliver load currents to compressor motors of individual air-conditioners, respectively, a common power supply for delivering an a.c. power to said frequency converters, control means for controlling said respective frequency converters, operating state detection means for detecting ON/OFF states of said respective frequency converters and for estimating a load current, means for estimating a total current of the frequency converters being operated in accordance with a detected result from said operating state detection means, and means responsive to a higher harmonic reduction command to classify said frequency converters being operated into two groups thereof so that said total current is substantially equally halved, to thus control one group of controllable rectifiers and the other group of controllable rectifiers so that there is a phase-control angle difference of substantially 30 degrees therebetween.
Claim 10
Dependent Claim
158 words
An adjustable a.c. power supply equipment for an air-conditioner system comprising: three sets of frequency converters each comprised of a three-phase controllable rectifier and an inverter to deliver load currents to compressor motors of individual air-conditioners, respectively, a common power supply for delivering an a.c. power to said frequency converters, control means for controlling said respective frequency converters, operating state detection means for detecting ON/OFF states of said respective frequency converters and for estimating a load current, means for estimating a total current of the frequency converters being operated in accordance with a detected result from said operating state detection means, and means responsive to a higher harmonic reduction command to classify said frequency converters being operated into two groups thereof so that said total current is substantially equally halved, to thus control one group of controllable rectifiers and the other group of controllable rectifiers so that there is a phase-control angle difference of substantially 30 degrees therebetween.
Claim 11
Dependent Claim
42 words
An adjustable a.c. power supply equipment as set forth in claim 7, wherein said one group of controllable rectifiers have a phase-control angle of zero degrees, and said the other group of controllable rectifiers have a phase-control angle of substantially 30 degrees.
Claim 12
Dependent Claim
47 words
An adjustable a.c. power supply equipment as set forth in claim 7, wherein said first frequency converter is comprised of a three-phase non-controllable rectifier and a LC-less inverters and said second frequency converter is comprised of a three-phase controllable rectifier and a capacitor input voltage type inverter.
Claim 13
Dependent Claim
50 words
An adjustable a.c. power supply equipment as set forth in claim 7, wherein said first frequency converter is comprised of a three-phase non-controllable rectifier and a capacitor input voltage type inverter, and said second frequency converter is comprised of a three-phase controllable rectifier and a capacitor input voltage type inverter.
References Cited (Backward Citations)
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