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US5047909A Expired / Lapsed US ⏱️ 0.0 years remaining

Power conversion apparatus with harmonic filtration

Assignee: Toshiba Corp
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Filing: 1990-10-29
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Granted: 1991-09-10
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Expires: 2010-10-29
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Abstract

Abstract A power conversion apparatus capable of eliminating inexpedient higher harmonic components from its output, without lowering the conversion efficiency. The apparatus includes a first power converter for converting an input power from a power supply into an output power; a detector for detecting an output current and an output voltage of the first power converter; a high harmonic detector for detecting a higher harmonic component on a basis of the output current and the output voltage, and for producing current reference signal corresponding to the detected higher harmonic component; and a second power converter for producing an inverse of the detected higher harmonic component according to the current reference signal, and combining the produced inverse of the higher harmonic component with the output current of the first power converter such that the higher harmonic component in the output current of the first power converter are cancelled by the inverse of the higher harmonic component.

Inventors

  • 👤 Hiromi Hosoda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 16:22
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/06; H02M; H02M1/00; H02M1/12; H02M5/00

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 159 words
A power conversion apparatus with harmonic filtration, comprising: first power converter means for converting an input power from a power supply into an output power; detector means, connected to an output side of the first power converter means, for detecting an output current and an output voltage of the first power converter means; higher harmonic detector means, connected to the detector means, for detecting a higher harmonic component on a basis of the output current and the output voltage, and for producing current reference signal corresponding to the detected higher harmonic component; and second power converter means for producing an inverse of the detected higher harmonic component according to the current reference signal, and combining the produced inverse of the higher harmonic component with the output current of the first power converter means such that the higher harmonic component in the output current of the first power converter means is cancelled by the inverse of the higher harmonic component.
Claim 2
Dependent Claim 159 words
A power conversion apparatus with harmonic filtration, comprising: first power converter means for converting an input power from a power supply into an output power; detector means, connected to an output side of the first power converter means, for detecting an output current and an output voltage of the first power converter means; higher harmonic detector means, connected to the detector means, for detecting a higher harmonic component on a basis of the output current and the output voltage, and for producing current reference signal corresponding to the detected higher harmonic component; and second power converter means for producing an inverse of the detected higher harmonic component according to the current reference signal, and combining the produced inverse of the higher harmonic component with the output current of the first power converter means such that the higher harmonic component in the output current of the first power converter means is cancelled by the inverse of the higher harmonic component.
Claim 3
Dependent Claim 25 words
The apparatus of claim 1, wherein the higher harmonic detector means includes means for eliminating a predetermined higher harmonic component and a fundamental harmonic component.
Claim 4
Dependent Claim 16 words
The apparatus of claim 1, wherein the second converter means includes an additional independent power supply.
Claim 5
Dependent Claim 152 words
The apparatus of claim 1, further comprising: second detector means, connected to an input side of the first power converter means, for detecting an input current and an input voltage of the first power converter means; second higher harmonic detector means, connected to the second detector means, for detecting an input higher harmonic component on a basis of the input current and the input voltage, and for producing second current reference signal corresponding to the detected input higher harmonic component; and third power converter means for producing an inverse of the detected input higher harmonic component according to the second current reference signal, and combining the produced inverse of the input higher harmonic component with the input current of the first power converter means such that the input higher harmonic component in the input current of the first power converter means is cancelled by the inverse of the input higher harmonic component.
Claim 6
Dependent Claim 27 words
The apparatus of claim 4, wherein the second higher harmonic detector means includes means for eliminating a predetermined input higher harmonic component and a fundamental harmonic component.
Claim 7
Dependent Claim 13 words
The apparatus of claim 1, wherein the first converter means is a cycloconverter.
Claim 8
Dependent Claim 14 words
The apparatus of claim 1, wherein the first converter means is a thyristor inverter.
Claim 9
Dependent Claim 28 words
The apparatus of claim 1, wherein the second converter means comprises an inverter and a current controller for controlling the inverter in accordance with the current reference signal.
Claim 10
Dependent Claim 12 words
The apparatus of claim 8, wherein the inverter includes a power transistor.
Claim 11
Dependent Claim 12 words
The apparatus of claim 8, wherein the inverter includes a gate turnoff.
Claim 12
Dependent Claim 17 words
The apparatus of claim 1, wherein the input current from the power supply is an AC current.
Claim 13
Dependent Claim 17 words
The apparatus of claim 1, wherein the input current from the power supply is a DC current.
Claim 14
Dependent Claim 69 words
The apparatus of claim 1, wherein the higher harmonic detector means includes a filter means for obtaining two-phase current from the detected output current, a fundamental harmonic remover means for removing a fundamental harmonic component from the two-phase current in order to obtain the higher harmonic component, and a current reference calculator means for calculating the current reference signal in three-phase which is corresponding to the higher harmonic component.

References Cited (Backward Citations)

US3825815A Cited
US4241395A Cited
US4377780A Cited
JPS59162773A Cited
JPS6039374A Cited
JPS62277065A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-09 1995-03-11 1995-09-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-09 1999-03-11 1999-09-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-09 2003-03-11 2003-09-10 $7700.00 Window Closed / Lapsed

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