Energy Supply for a Blade Adjustment Device Pertaining to a Wind Energy Installation

• US 20090001726A1
• Filed: 02/23/2007
• Published: 01/01/2009
• Est. Priority Date: 02/24/2006
• Status: Active Grant

• Current Assignee: Siemens Gamesa Renewable Energy Service GmbH (Siemens AG)
• Original Assignee: REpower Systems AG (Senvion SE)
• Inventors: Warfen, Karsten, Letas, Heinz-Hermann
• Granted Patent: US 8,405,237 B2
• Time in Patent Office: Days
• US Class Current: 290/44
• CPC Class Codes: F03D 7/0224 Adjusting blade pitch
• CPC Class Codes: F05B 2260/76 the adjusting mechanism using auxiliary power sources
• CPC Class Codes: F05B 2270/1074 by using back-up controls
• CPC Class Codes: H02H 3/18 responsive to reversal of direct current
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• 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 wind energy installation includes a tower provided with rotor blades that are adjusted using a servomotor connected to a pitch circuit and an emergency circuit. During normal operation the rotor blades are actuated by the pitch circuit and during emergency operation are actuated by the emergency circuit. The emergency circuit has an electric energy store, a switching device, connection lines to the servomotor and a protection device which includes comprises a power flow detector module (60) designed for determining whether electric power flows into or from the servomotor and a discharge module designed to limit the voltage and/or current in the emergency circuit in the case of a power flow from the servomotor.

Claims

1-14. -14. (canceled)

15. A wind energy installation, comprising:

a rotor with rotor blades, the angle of incidence on which can be changed using a pitch adjustment device, and

a servomotor connected to a pitch circuit and an emergency circuit,

the rotor blades during normal operation being actuated by the pitch circuit and during emergency operation being actuated by the emergency circuit, and the emergency circuit comprising an electric energy store, a switching device, connection lines to the servomotor and a protection device,

wherein the protection device comprises a power flow detector module configured to determine whether electric power flows into or from the servomotor and a discharge module configured to limit a voltage or a current in the emergency circuit in the case of a power flow from the servomotor.

16. The wind energy installation of claim 15, wherein the power flow detector module is configured to determine the voltage in the emergency circuit and the discharge) is configured to limit the voltage in the case of power flow from the servomotor.

17. The wind energy installation of claim 16, wherein the discharge module comprises a setpoint value change module configured so that, during emergency operation, the voltage in the emergency circuit is set to a value which is above the rated voltage of the electric energy store.

18. The wind energy installation of claim 17, wherein the voltage in the emergency circuit is set to a value which is at least approximately 5% above the rated voltage of the electric energy store.

19. The wind energy installation of claim 17, wherein the voltage in the emergency circuit is set to a value which is at most approximately 20% above the rated voltage of the electric energy store.

20. The wind energy installation of claim 15, wherein the power flow detector module is configured to determine the current in the emergency circuit, and the discharge module redirects the current in the case of a power flow from the servomotor.

21. The wind energy installation of claim 15, 16 or 17, wherein the discharge module comprises at least one brake chopper with at least one brake resistor.

22. The wind energy installation of claim 21, wherein the brake chopper is part of a converter and, during emergency operation, is connected via a switching element to the emergency circuit.

23. The wind energy installation of claim 22, wherein the brake chopper is connected to an intermediate circuit of the converter.

24. The wind energy installation of claim 22, wherein the brake chopper is connected to an inverter or an H-bridge circuit of the converter.

25. The wind energy installation of claim 21, wherein the discharge module further comprises a system isolation device which isolates the converter from its supply system.

26. The wind energy installation of claim 15, 16 or 17, wherein the servomotor is of a redundant design with a motor of the pitch circuit and a motor of the emergency circuit.

27. The wind energy installation of claim 26, wherein the motor of the pitch circuit is a three-phase motor and the motor of the emergency circuit is a DC motor.

28. The wind energy installation of claim 26, wherein at least the motor of the pitch circuit is connected to the rotor blade via a disengageable clutch or a shear connection.

29. A method for adjusting rotor blades of a rotor in a wind energy installation by a servomotor of a pitch adjustment device, comprising

determining a power flow in an emergency circuit in the wind energy installation,

determining whether a normal condition or an emergency condition exists in the wind energy installation,

limiting electric power flowing from the servomotor during the emergency condition by limiting the voltage or the current in the emergency circuit, and

changing the angle of incidence of the rotor blades using the pitch adjustment device,

wherein, during the normal condition, the adjustment is carried out via a pitch circuit and, during the emergency condition, the adjustment is carried out via an emergency circuit.

30. The method of claim 29, wherein:

the servomotor is connected to a pitch circuit and an emergency circuit,

the rotor blades during normal operation are actuated by the pitch circuit and during emergency operation are actuated by the emergency circuit, the emergency circuit comprising an electric energy store, a switching device, connection lines to the servomotor and a protection device and

the protection device comprises a power flow detector module configured to determine whether electric power flows into or from the servomotor and a discharge module configured to limit a voltage or a current in the emergency circuit in the case of a power flow from the servomotor.