Power generation apparatus using AC energization synchronous generator and method of controlling the same

• US 7,453,242 B2
• Filed: 02/14/2008
• Issued: 11/18/2008
• Est. Priority Date: 07/27/2005
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ichinose, Masaya, Futami, Motoo, Matsutake, Mitsugu, Oohara, Shinya, Imaie, Kazuhiro
• Primary Examiner(s): Ponomarenko; Nicholas
• Application Number:
  US12/031,262
• Publication Number:
  US 20080143113A1
• Time in Patent Office: 278 Days
• Field of Search: 322/20, 322/22, 322/27, 322/28, 322/29, 322/45, 290/44
• US Class Current: 322/29
• CPC Class Codes: H02P 2101/15 for wind-driven turbines
• CPC Class Codes: H02P 9/007 Control circuits for doubly fed generators
• CPC Class Codes: H02P 9/42 to obtain desired frequency without varying speed of the generator

Abstract

A power generation apparatus and method includes an AC energization synchronous generator, a switching device for connecting to a network disposed on a stator side of the AC energization synchronous generator, an energizing device for applying a variable frequency AC to a secondary winding of the AC energization synchronous generator, and a first voltage detection unit for detecting a voltage of the switching device on the stator side. A rotational frequency of the AC energization synchronous generator is estimated or calculated based on a frequency of a stator side voltage of the switching device, while the switching device is open.

Claims

1. A power generation apparatus comprising:

an AC energization synchronous generator;

a switching device for connecting to a network disposed on a stator side of said AC energization synchronous generator;

an energizing device for applying a variable frequency AC to a secondary winding of said AC energization synchronous generator;

a first voltage detection unit for detecting a voltage of said switching device on the stator side; and

a control unit for estimating a rotational frequency of said AC energization synchronous generator based on a frequency of a stator side voltage of said switching device, while said switching device is open.

2. A power generation apparatus according to claim 1, wherein said control unit adjusts the frequency of AC from said energizing device to control the frequency of a stator side voltage of said switching device.

3. A power generation apparatus according to claim 2, further comprising a second voltage detection unit for detecting a network side voltage of said switching device, wherein said control unit adjusts the frequency of AC from said energizing device to make the frequency of a stator side voltage of said switching device be coincident with a network side frequency of said switching device.

4. A method of generating electric power for a power generation apparatus, said power generation apparatus including:

an AC energization synchronous generator;

a switching device for connecting to a network disposed on a stator side of said AC energization synchronous generator;

an energizing device for applying a variable frequency AC to a secondary winding of said AC energization synchronous generator; and

a first voltage detection unit for detecting a voltage of said switching device on the stator side, wherein said method comprises the step of;

calculating a rotational frequency of said AC energization synchronous generator using information about a frequency of a stator side voltage of said switching device, while said switching device is open.

5. A method according to claim 4, further comprising the step of adjusting the frequency of AC from said energizing device to control the frequency of a stator side voltage of said switching device.

6. A method according to claim 5, wherein said power generation apparatus further includes a second voltage detection unit for detecting a network side voltage of said switching device, wherein said method further comprises the steps of:

adjusting the frequency of AC from said energizing device to make the frequency of a stator side voltage of said switching device be coincident with a network side frequency of said switching device; and

closing said switching device when the frequency of the stator side voltage of said switching device is coincident with the network side frequency of said switching device.

7. A wind power generation apparatus comprising:

an AC energization synchronous generator having a rotor connected to a wind turbine;

a switching device for connecting to a network disposed on a stator side of said AC energization synchronous generator;

an energizing device for applying a variable frequency AC to a secondary winding of said AC energization synchronous generator;

a first voltage detection unit for detecting a voltage of said switching device on the stator side; and

a control unit for estimating a rotational frequency of said AC energization synchronous generator based on a frequency of a stator side voltage of said switching device, while said switching device is open.

8. A wind power generation apparatus according to claim 7, wherein said control unit adjusts the frequency of AC from said energizing device to control the frequency of a stator side voltage of said switching device.

9. A wind power generation apparatus according to claim 8, further comprising a second voltage detection unit for detecting a network side voltage of said switching device, wherein said control unit adjusts the frequency of AC from said energizing device to make the frequency of a stator side voltage of said switching device to be coincident with a network side frequency of said switching device.