Wind Power Generation Apparatus, Wind Power Generation System and Power System Control Apparatus

• US 20080106099A1
• Filed: 05/22/2007
• Published: 05/08/2008
• Est. Priority Date: 11/02/2006
• Status: Active Grant

• Current Assignee: Hitachi Industrial Products, Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Ichinose, Masaya, Futami, Motoo, Oohara, Shinya
• Granted Patent: US 7,642,666 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 7/0284 in relation to the state of the electric grid
• CPC Class Codes: F03D 7/042 by means of an electrical or electronic controller
• CPC Class Codes: F03D 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: H02P 2101/15 for wind-driven turbines
• CPC Class Codes: H02P 23/26 Power factor control [PFC]
• CPC Class Codes: H02P 9/007 Control circuits for doubly fed generators
• CPC Class Codes: H02P 9/305 controlling voltage H02P9/302 takes precedence
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

An interface device transmits a reactive power command depending on a power system from a voltage regulation device of the power system to a wind power generation apparatus electrically connected to the power system, and the wind power generation apparatus receives the reactive power command. Then, the wind power generation apparatus outputs reactive power according to a value obtained by adding, to a reactive power command, another reactive power command for suppression of voltage fluctuation caused by output power of the wind power generation apparatus.

Claims

1. A wind power generation apparatus having a wind turbine which receives wind and rotates, a generator which generates electric power by the rotating wind turbine, and a power converter which converts the electric power generated by the generator, wherein

the wind power generation apparatus is electrically connected to a power system, and comprises:

an interface device for receiving a first reactive power command value generated from a voltage detection value detected by a voltage detector provided for the power system;

means for generating a second reactive power command value for suppression of voltage fluctuation by fluctuating output power of the generator;

reactive power command value addition means for adding the first reactive power command value to the second reactive power command value; and

means for outputting reactive power according to a third reactive power command value output by the reactive power command value addition means.

2. The wind power generation apparatus according to claim 1, wherein

when a plurality of wind power generation apparatuses are electrically connected to the power system,

a first wind power generation apparatus having small output active power in the plurality of wind power generation apparatuses outputs larger reactive power than a second wind power generation apparatus having large output active power.

3. The wind power generation apparatus according to claim 1, wherein

when the plurality of wind power generation apparatuses are electrically connected to the power system,

a first wind power generation apparatus having large output active power in the plurality of wind power generation apparatuses outputs smaller reactive power than a second wind power generation apparatus having small output active power.

4. The wind power generation apparatus according to claim 1, wherein:

the interface device receives a delay reactive power command value when the voltage detection value of the voltage detector is higher than a predetermined value;

the interface device receives an advance reactive power command value when the voltage detection value is lower than the predetermined value; and

reactive power is output to the power system in such a way that the voltage detection value is within a predetermined range.

5. The wind power generation apparatus according to claim 1, further comprising

generated power control means for independently controlling active power and reactive power.

6. A power system control apparatus which controls a power system electrically connected to a wind power generation apparatus having a wind turbine which receives wind and rotates, a generator which generates electric power by the rotating wind turbine, and a power converter which converts the electric power generated by the generator, said apparatus comprising:

a voltage detector for detecting a voltage of the power system;

a reactive power command value generation unit for generating a reactive power command value from a voltage detection value of the voltage detector; and

transmission unit for transmitting the reactive power command value to the wind power generation apparatus, wherein

output fluctuation of the generator is suppressed, and reactive power according to the reactive power command is transmitted from the wind power generator to the power system.

7. The power system control apparatus according to claim 6, wherein

when a plurality of wind power generation apparatuses are electrically connected to the power system,

the reactive power command value generation unit comprises means for transmitting a reactive power command value larger than a value of a second wind power generation apparatus having larger output active power to a first wind power generation apparatus having small output active power in the plurality of wind power generation apparatuses.

8. The power system control apparatus according to claim 6, wherein

when a plurality of wind power generation apparatuses are electrically connected to the power system,

the reactive power command value generation unit comprises means for transmitting a reactive power command value smaller than a value of a second wind power generation apparatus having smaller output active power to a first wind power generation apparatus having large output active power in the plurality of wind power generation apparatuses.

9. The power system control apparatus according to claim 6, wherein:

the reactive power command value generation unit generates a delay reactive power command when the voltage detection value is higher than a predetermined value;

the unit generates an advance reactive power command when the voltage detection value is lower than the predetermined value; and

a first reactive power command value is changed in such a way that the voltage detection value is in a predetermined range.

10. A wind power generation system in which a wind power generation apparatus having a wind turbine which receives wind and rotates, a generator which generates electric power by the rotating wind turbine, and a power converter which converts the electric power generated by the generator is electrically connected to a power system, wherein:

the wind power generation system comprises;

a voltage detector for detecting a voltage of the power system;

a reactive power command value generation unit for generating a first reactive power command value from a voltage detection value of the voltage detector; and

a transmission unit for transmitting the first reactive power command value to the wind power generation apparatus, and

the wind power generation apparatus comprises;

an interface device for receiving the first reactive power command value;

means for generating a second reactive power command value for suppression of voltage fluctuation by fluctuating output power of the generator;

reactive power command value addition means for adding the first reactive power command value to the second reactive power command value; and

means for outputting reactive power according to a third reactive power command value output by the reactive power command value addition means.

11. The wind power generation system according to claim 10, wherein

when a plurality of wind power generation apparatuses are electrically connected to the power system,

a first wind power generation apparatus having small output active power in the plurality of wind power generation apparatuses outputs larger reactive power than a second wind power generation apparatus having large output active power.

12. The wind power generation system according to claim 10, wherein

when the plurality of wind power generation apparatuses are electrically connected to the power system,

a first wind power generation apparatus having large output active power in the plurality of wind power generation apparatuses outputs smaller reactive power than a second wind power generation apparatus having small output active power.

13. The wind power generation system according to claim 10, wherein:

the interface device receives a delay reactive power command value when the voltage detection value of the voltage detector is higher than a predetermined value;

the interface device receives an advance reactive power command value when the voltage detection value is lower than the predetermined value; and

reactive power is output to the power system in such a way that the voltage detection value is within a predetermined range.

14. The wind power generation system according to claim 10, wherein

the wind power generation apparatus comprises generated power control means capable of independently controlling active power and reactive power.