Control device of power conversion device

Patent metadata

Field	Value
Publication number	US-10461660-B2
Application number	US-201616090336-A
Country	US
Kind code	B2
Filing date	Apr 12, 2016
Priority date	Apr 12, 2016
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A control device of a power converter includes first and second switching circuits. The device converts AC power supplied from an AC power supply into DC power, and supplies the DC power to the DC circuit. First converter arms are connected in series in the first switching circuit. Second converter arms are connected in series in the second switching circuit. The device further includes first and second control circuits connected to the first and the second switching circuits and control gate pulses of each of the first and the second arms respectively. A first and a second power interruption compensation circuits supply power to the first and the second control circuits for prescribed durations in power interruptions of the first and the second control circuits respectively.

First claim

The invention claimed is:

1. A control device of a power conversion device converting alternating current power into direct current power and supplying the direct current power to a direct current circuit, the alternating current power being supplied from an alternating current power supply, the power conversion device being separately-excited and including a first switching circuit, a second switching circuit, and a third switching circuit, the first switching circuit including a first converter arm and a second converter arm connected in series at a first alternating current connection point, the second switching circuit including a third converter arm and a fourth converter arm connected in series at a second alternating connection point, the third switching circuit including a fifth converter arm and a sixth converter arm connected in series at a third alternating current connection point, the first alternating current connection point capable to be connected to a first phase of the alternating current power, the second alternating current connection point capable to be connected to a second phase of the alternating current power, the third alternating current connection point capable to be connected to a third phase of the alternating current power, one end of the first switching circuit, one end of the second switching circuit, and one end of the third switching circuit capable to be connected to a high-voltage side of the direct current circuit, another end of the first switching circuit, another end of the second switching circuit, and another end of the third switching circuit capable to connected to a low-voltage side of the direct current circuit, the control device comprising:
a first control circuit controlling a gate pulse of each of the first converter arm and the second converter arm included in the first switching circuit;
a second control circuit controlling a gate pulse of each of the third converter arm and the fourth converter arm included in the second switching circuit; and
a third control circuit controlling a gate pulse of each of the fifth converter arm and sixth converter arm included in the third switching circuit,
the first control circuit including a first power interruption compensation circuit supplying electrical power to the first control circuit for a prescribed amount of time during a power interruption of the first control circuit,
the second control circuit including a second power interruption compensation circuit supplying electrical power to the second control circuit for a prescribed amount of time during a power interruption of the second control circuit, and
the third control circuit including a third power interruption compensation circuit supplying electrical power to the third control circuit for a prescribed amount of time during a power interruption of the third control circuit.

2. The control device of the power conversion device according to claim 1 , further comprising:
a higher-level control circuit connected to each of the first control circuit, the second control circuit, and the third control circuit;
a first abnormality detection circuit sensing an abnormality of the first control circuit;
a second abnormality detection circuit sensing an abnormality of the second control circuit; and
a third abnormality detection circuit sensing an abnormality of the third control circuit,
when normal, the higher-level control circuit outputs, to the first control circuit, a phase control pulse of each of the plurality of first converter arms included in the first switching circuit, and outputs, to the second control circuit, a phase control pulse of each of the plurality of second converter arms included in the second switching circuit, and outputs, to the third control circuit, a phase control pulse of each of the plurality of third converter arms included in the third switching circuit,
in the case where a signal is received from the first abnormality detection circuit, the higher-level control circuit stops the output of the phase control pulse to the first control circuit and outputs, to the second control circuit and the third control circuit, a first bypass pair command causing at least one of the second switching circuit or the third switching circuit to a bypass pair state, the first bypass pair command causing the third converter arm and the fourth converter arm to conduct simultaneously or the fifth converter arm and the sixth converter arm to conduct simultaneously,
in the case where a signal is received from the second abnormality detection circuit, the higher-level control circuit stops the output of the phase control pulse to the second control circuit and outputs, to the first control circuit and the third control circuit, a second bypass pair command causing at least one of the first switching circuit or the third switching circuit to a bypass pair state, the second bypass pair command causing the first converter arm and the second converter arm to conduct simultaneously or the fifth converter arm and the sixth converter arm to conduct simultaneously,
in the case where a signal is received from the third abnormality detection circuit, the higher-level control circuit stops the output of the phase control pulse to the third control circuit and outputs, to the first control circuit and the second control circuit, a third bypass pair command causing at least one of the first switching circuit or the second switching circuit to a bypass pair state, the third bypass pair command causing the first converter arm and the second converter arm to conduct simultaneously or the third converter arm and the fourth converter arm to conduct simultaneously.

3. The control device of the power conversion device according to claim 2 , wherein the prescribed amount of time is not less than a time from when the bypass pair command is output until one of the first converter arm, the second converter arm, or the third converter arm not receiving the bypass pair command turns off.

4. The control device of the power conversion device according to claim 3 , wherein
the first control circuit further includes a first control power supply supplying a power supply to the first control circuit,
the first abnormality detection circuit further has a function of sensing the power interruption of the first control circuit by monitoring a state of the first control power supply,
the second control circuit further includes a second control power supply supplying a power supply to the second control circuit,
the second abnormality detection circuit further has a function of sensing the power interruption of the second control circuit by monitoring a state of the second control power supply,
the third control circuit further includes a third control power supply supplying a power supply to the third control circuit, and
the third abnormality detection circuit further has a function of sensing the power interruption of the third control circuit by monitoring a state of the third control power supply.

5. The control device of the power conversion device according to claim 4 , wherein
the first abnormality detection circuit further has a function of sensing an abnormality of the gate pulses of the first control circuit by monitoring a state of the gate pulses of the first control circuit,
the second abnormality detection circuit further has a function of sensing an abnormality of the gate pulses of the second control circuit by monitoring a state of the gate pulses of the second control circuit, and
the third abnormality detection circuit further has a function of sensing an abnormality of the gate pulses of the third control circuit by monitoring a state of the gate pulses of the third control circuit.

6. The control device of the power conversion device according to

Assignees

• Toshiba Mitsubishi Elec Ind

Inventors

• Usuki Kazuhiro
• Ohkami Tomohisa

Classifications

• H02M7/155

  using semiconductor devices only · CPC title

• H02J3/36

  Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links · CPC title

• H02M7/48

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02M1/34

  Snubber circuits · CPC title

• H02M1/08 Primary

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title