WIND-TURBINE-GENERATOR CONTROL SYSTEM, WIND TURBINE GENERATOR, AND WIND-TURBINE-GENERATOR CONTROL METHOD

• US 20130214536A1
• Filed: 04/03/2013
• Published: 08/22/2013
• Est. Priority Date: 02/06/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: WAKASA, Tsuyoshi, MURATA, Naoto, AYAGI, Tsuyoshi, AIBA, Kenichi
• Granted Patent: US 9,581,138 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 9/255 connected to electrical distribution networks; Arrangements therefor
• CPC Class Codes: F05B 2270/304 Spool rotational speed
• CPC Class Codes: F05B 2270/335 Output power or torque
• CPC Class Codes: F05B 2270/337 Electrical grid status parameters, e.g. voltage, frequency or power demand
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• 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

Abstract

A power-converter controller is provided in a wind turbine generator which is interconnected to a utility grid and in which a generator generates electrical power by rotation of a rotor having blades. The power-converter controller includes a voltage sensor that measures a generator terminal voltage, resonance-component extracting sections that extract an electrical resonance component generated due to the interconnection from a measurement result measured by the voltage sensor, and a control section and a control section that control a current that flows to the utility grid so as to suppress the resonance component, on the basis of the resonance component extracted by the resonance-component extracting sections. Accordingly, the power-converter controller can more effectively suppress the resonance generated due to the interconnection of the wind turbine generator to the utility grid.

Claims

1. A wind-turbine-generator control system which is interconnected to a utility grid and in which a generator generates electrical power by rotation of a rotor having blades, the control unit comprising:

a measuring unit for measuring at least one of a voltage applied to the generator, a shaft rotational speed of the generator, and a shaft torque of the generator;

a extracting unit for extracting an electrical resonance component generated due to the interconnection from the measurement result measured by the measuring unit; and

a current control unit for controlling a current that flows to the utility grid so as to suppress the resonance component, on the basis of the resonance component extracted by the extracting unit.

2. The wind-turbine-generator control system according to claim 1, wherein

the wind turbine generator includes a generator-side power converting unit for converting AC power generated in a rotor winding of the generator to DC power and outputting the DC power to a DC bus and a grid-side power converting unit for converting the DC power received from the DC bus to AC power with the same frequency as that of the utility grid and outputting the AC power to the utility grid;

and

the current control unit controls an electrical current flowing from the grid-side power converting unit to the utility grid so as to suppress the resonance component, on the basis of the resonance component extracted by the extracting unit.

3. The wind-turbine-generator control system according to claim 1, wherein when extracting the resonance component from the shaft rotational speed of the generator, the extracting unit extracts, as the resonance component, a component at a frequency obtained by subtracting the original frequency of the resonance component from the frequency of the utility grid.

4. The wind-turbine-generator control system according to claim 1, wherein when the magnitude of the resonance component extracted by the extracting unit exceeds a predetermined threshold value, the wind turbine generator is stopped.

5. A wind turbine generator comprising the control unit according to claim 1.

6. A wind-turbine-generator control method which is interconnected to a utility grid and in which a generator generates electrical power by rotation of a rotor having blades, the method comprising:

measuring at least one of a voltage applied to the generator, a shaft rotational speed of the generator, and a shaft torque of the generator;

extracting an electrical resonance component generated due to the interconnection from the measurement result measured in the measuring; and

controlling a current that flows to the utility grid so as to suppress the resonance component, on the basis of the resonance component extracted in the extracting.