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US4584636A Expired / Lapsed US ⏱️ 0.0 years remaining

AC-to-DC power converter with improved power factor and overvoltage suppression

Assignee: Hitachi Ltd
•
Filing: 1983-03-09
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Granted: 1986-04-22
•
Expires: 2003-03-09
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Abstract

Abstract An AC-to-DC power conversion by connecting GTO elements to the positive arms of a three-phase full wave bridge circuit and by repeating the mode of supplying power to a load from an AC power supply by controlling the GTO elements, and the mode of making the current flowing to the load flow back at the time of interruption of the power supply mode, when the power supply mode and the flow-back mode are switched over, overvoltage at the time of the switching is suppressed by simultaneously causing the power supply and flow-back currents to flow.

Inventors

  • 👤 Takeki Ando
  • 👤 Toshiaki Kurosawa
  • 👤 Hiroaki Kuroha
  • 👤 Yoshio Sakai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 11:29
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/02; H02M7/04; H02M7/12; H02M7/145; H02M7/155; H02M7/162; H02M7/1623

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 146 words
A power converter apparatus comprising an AC power supply, a DC load and controllable switching means connected across said AC power supply and said DC load and provided with a current-breaking function for alternately repeating the mode of rectifying said AC power and supplying power to said DC load and the mode of making the current flowing to said DC load flow back, pulse generating means for generating a gate-on pulse for one of the power supply mode and the flow-back mode and a gate-off pulse for one of the flow-back mode and the power supply mode, said power converter apparatus being futher provided with gate control means response to the gate pulses from said pulse generating means for controlling said controllable switching means so that said power supply current and said flow-back current simultaneously flow at the time of said power supply to flow-back-mode switching.
Claim 2
Dependent Claim 146 words
A power converter apparatus comprising an AC power supply, a DC load and controllable switching means connected across said AC power supply and said DC load and provided with a current-breaking function for alternately repeating the mode of rectifying said AC power and supplying power to said DC load and the mode of making the current flowing to said DC load flow back, pulse generating means for generating a gate-on pulse for one of the power supply mode and the flow-back mode and a gate-off pulse for one of the flow-back mode and the power supply mode, said power converter apparatus being futher provided with gate control means response to the gate pulses from said pulse generating means for controlling said controllable switching means so that said power supply current and said flow-back current simultaneously flow at the time of said power supply to flow-back-mode switching.
Claim 3
Dependent Claim 69 words
A power converter apparatus as claimed in claim 1, wherein said gate control means controls said controllable switching means in such a way that said flow-back current is made to rise during a period of time that said power supply current is attenuating, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the switching means due to the overvoltage is prevented.
Claim 4
Dependent Claim 69 words
A power converter apparatus as claimed in claim 1, wherein said gate control means controls said controllable switching means in such a manner that said power supply current is allowed to rise during a period of time that said flow-back current is attenuating, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the switching means due to the overvoltage is prevented.
Claim 5
Dependent Claim 43 words
A power converter apparatus as claimed in claim 1, wherein said gate control means enables said controllable switching means forming said flow-back mode to hold an on state while said controllable switching means forming said power supply mode is holding an off state.
Claim 6
Dependent Claim 40 words
A power converter apparatus as claimed in claim 1, wherein said gate control means enables simultaneous application of the gate-off pulse and the gate-on pulse for said controllable switching means forming said power supply mode and said flow-back mode, respectively.
Claim 7
Dependent Claim 42 words
A power converter apparatus as claimed in claim 1, wherein said gate control means enables said controllable switching means forming said power supply mode to hold an on state while said switching means forming said flow-back mode is holding an off state.
Claim 8
Dependent Claim 40 words
A power converter apparatus as claimed in claim 6, wherein said gate control means enables simultaneous application of the gate-off pulse and the gate-on pulse for said controllable switching means forming said flow-back mode and said power supply mode, respectively.
Claim 9
Dependent Claim 44 words
A power converter apparatus as claimed in claim 1, wherein a full wave bridge rectifier circuit is connected across said AC power supply and said DC load, said controllable switching means forming each of a plurality of arms of said full wave bridge circuit.
Claim 10
Dependent Claim 30 words
A power converter apparatus as claimed in claim 8, wherein said controllable swithcing means form the positive arm of said full wave bridge circuit, whereas thyristors form the negative arms.
Claim 11
Dependent Claim 54 words
A power converter apparatus as claimed in claim 8, wherein said power supply mode is formed by making any of said controllable switching means of said full wave bridge circuit conduct, whereas said flow-back mode is formed by making said controllable switching means forming arms forming a closed loop with said DC load conduct.
Claim 12
Dependent Claim 55 words
A power converter apparatus as claimed in claim 10, wherein said gate control means operates to overlap a terminating point of a period during which said controllable switching means forming said power supply mode is conducting and a starting point of a period during which said controllable switching means forming said flowback mode is conducting.
Claim 13
Dependent Claim 55 words
A power converter apparatus as claimed in claim 10, wherein said gate control means operates to overlap a terminating point of a period during which said controllable switching means forming said flow-back mode is conducting and a starting point of a period during which said controllable switching means forming said power supply mode is conducting.
Claim 14
Dependent Claim 172 words
A power converter apparatus comprising an AC power source, a DC load, and a plurality of controllable switching means connected between said AC power source and said DC load and each having an electric current cut-off function for enabling a switching in accordance with gate pulses cyclically between a power-supply mode in which the current from said AC power source is rectified and supplied to said DC load and a flow-back mode in which the electric current in said DC load is fed back, pulse generating means for generating a gate-on pulse for said flow-back mode before the generation of a gate-off pulse for said power-supply mode, and means for supplying gate pulses to said controllable switching means in response to the generated pulses from said pulse generating means for enabling power-supply current and flow-back current to simultaneously flow at a time of mode switching, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the controllable switching means due to the overvoltage is prevented.
Claim 15
Dependent Claim 172 words
A power converter apparatus comprising an AC power source, a DC load, and a plurality of controllable switching means connected between said AC power source and said DC load and each having an electric current cut-off function for enabling a switching in accordance with gate pulses cyclically between a power-supply mode in which the current from said AC power source is rectified and supplied to said DC load and a flow-back mode in which the electric current in said DC load is fed back, pulse generating means for generating a gate-on pulse for said flow-back mode before the generation of a gate-off pulse for said power-supply mode, and means for supplying gate pulses to said controllable switching means in response to the generated pulses from said pulse generating means for enabling power-supply current and flow-back current to simultaneously flow at a time of mode switching, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the controllable switching means due to the overvoltage is prevented.
Claim 16
Dependent Claim 43 words
A power converter apparatus as claimed in claim 13, wherein a full wave bridge circuit is connected across said AC power supply and said DC load, said controllable switching means forming each of a plurality of arms of said full wave bridge circuit.
Claim 17
Dependent Claim 38 words
A power converter apparatus as claimed in claim 14, wherein said controllable switching means form the positive arm of said full wave bridge circuit, whereas thyristors are connected to the negative arms of said full wave bridge circuit.
Claim 18
Dependent Claim 53 words
A power converter apparatus as claimed in claim 14, wherein said power-supply mode is formed by making any of said controllable switching means forming said full wave bridge circuit conduct, whereas said flow-back mode is formed by making said controllable switching means forming arms forming a closed loop with said DC load conduct.
Claim 19
Dependent Claim 171 words
A power converter apparatus comprising an AC power source, a DC load, and a plurality of controllable switching means connected between said AC power source and said DC load and each having an electric current cut-off function for enabling switching in accordance with gate pulses cyclically between a power-supply mode in which the current from said AC power source is rectified and supplied to said DC load and a flow-back mode in which the electric current in said DC load is fed back, pulse generating means for generating a gate-on pulse for said power-supply mode before the generation of a gate-off pulse for said flow-back mode, and means for supplying gate pulses to said controllable switching means in response to the generated pulses from said pulse generation means for enabling power-supply current and flow-back current to simultaneously flow at a time of mode switching, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the controllable switching means due to the overvoltage is prevented.
Claim 20
Dependent Claim 171 words
A power converter apparatus comprising an AC power source, a DC load, and a plurality of controllable switching means connected between said AC power source and said DC load and each having an electric current cut-off function for enabling switching in accordance with gate pulses cyclically between a power-supply mode in which the current from said AC power source is rectified and supplied to said DC load and a flow-back mode in which the electric current in said DC load is fed back, pulse generating means for generating a gate-on pulse for said power-supply mode before the generation of a gate-off pulse for said flow-back mode, and means for supplying gate pulses to said controllable switching means in response to the generated pulses from said pulse generation means for enabling power-supply current and flow-back current to simultaneously flow at a time of mode switching, whereby an overvoltage occurring at the time of the mode switching is suppressed and a breakdown of the controllable switching means due to the overvoltage is prevented.
Claim 21
Dependent Claim 44 words
A power converter apparatus as claimed in claim 17, wherein a full wave bridge circuit is connected across said AC power supply and said DC load, said controllable switching means forming to each of a plurality of arms of said full wave bridge circuit.
Claim 22
Dependent Claim 36 words
A power converter apparatus as claimed in claim 18, wherein said switching means forming the positive arm of said full wave bridge circuit, whereas thyristors forming the negative arms of said controllable full wave bridge circuit.
Claim 23
Dependent Claim 53 words
A power converter apparatus as claimed in claim 18, wherein said power-supply mode is formed by making any of said controllable switching means forming said full wave bridge circuit conduct, whereas said flow-back mode is formed by making said controllable switching means forming arms forming a closed loop with said DC load conduct.

References Cited (Backward Citations)

US3622862A Cited
US3842335A Cited
US4245293A Cited
US4272807A Cited
GB2076233A Cited
US4361866A Cited
US4447868A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-04-21 1989-10-21 1990-04-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-04-21 1993-10-21 1994-04-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-04-21 1997-10-21 1998-04-22 $7700.00 Window Closed / Lapsed

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