Generator excitation apparatus and power conversion system

Patent metadata

Field	Value
Publication number	US-9374030-B2
Application number	US-201414314127-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Jun 28, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

According to one embodiment, there is provided a generator excitation apparatus including a plurality of first power converters and a second power converter. The plurality of first power converters are electrically connected to windings of respective phases of rotors of a wound rotor type induction generator in which the windings of the rotors of the respective phases are electrically independent, and are configured to bidirectionally convert DC and AC. The second power converter is configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase DC power supply. The DC sides of the first power converters are electrically connected together to a DC side of the second power converter.

First claim

The invention claimed is:

1. A generator excitation apparatus comprising:
a plurality of first power converters electrically connected to windings of respective three phases of a rotor of a wound rotor type induction generator in which the windings of the three phases of the rotor are electrically independent, and configured to bidirectionally convert DC and AC; and
a second power converter configured to bidirectionally convert DC and AC between DC sides of the first power converters and a three-phase AC power supply,
wherein the DC sides of the first power converters are electrically connected together to a DC side of the second power converter.

2. The apparatus according to claim 1 , wherein
the second power converter converts a three-phase AC voltage output from the three-phase AC power supply into a DC voltage, and
the first power converter converts the DC voltage converted by the second power converter into a single-phase AC voltage corresponding to each phase of the wound rotor type induction generator.

3. The apparatus according to claim 1 , wherein
the first power converters each comprise, for each of the three phases of the wound rotor type induction generator, a circuit including a plurality of switching elements electrically connected in series and divided by a neutral point, and
the second power converter comprises a circuit, including a plurality of switching elements electrically connected in series and divided by a neutral point.

4. The apparatus according to claim 1 , further comprising over voltage protection circuits formed on AC sides of the first power converters, and configured to shortcircuit, for the respective three phases, the windings of the rotor of the wound rotor type induction generator when an over voltage is applied to the windings.

5. The apparatus according to claim 1 , further comprising:
a stop control unit configured to stop the first power converter when an over voltage is applied to the winding of the rotor of the wound rotor type induction generator;
a first over voltage protection circuit electrically connected to high-potential sides of the respective three phases on AC sides of the first power converters, and configured to shortcircuit one-end sides of the windings of the respective three phases of the wound rotor type induction generator with the first power converters being stopped; and
a second over voltage protection circuit electrically connected to low-potential sides of the respective three phases on the AC sides of the first power converters, and configured to shortcircuit the other-end sides of the windings of the respective three phases of the wound rotor type induction generator with the first power converters being stopped.

6. A power conversion system comprising:
a wound rotor type induction generator in which windings of three phases of a rotor are electrically independent;
a plurality of first power converters electrically connected to the windings of the respective three phases of the rotor of the wound rotor type induction generator, and configured to bidirectionally convert DC and AC; and
a second power converter configured to bidirectionally convert DC and AC between DC sides of the first power converters and an AC power supply,
wherein the DC sides of the first power converters are electrically connected together to a DC side of the second power converter.

Assignees

• Toshiba Kk

Inventors

• Inagaki Katsuhisa
• Suzuki Kentaro
• Hasegawa Ryuta
• Ishizuki Teruyuki
• Kusunoki Kiyoshi

Classifications

• H02M1/14

  Arrangements for reducing ripples from DC input or output · CPC title

• H02P9/38

  Self-excitation by current derived from rectification of both output voltage and output current of generator · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• H02M7/493 Primary

  the static converters being arranged for operation in parallel · CPC title

• H02P9/302 Primary

  Brushless excitation · CPC title