Patent ID: 9574548
Date: 2017-02-21
CPC Classifications: F03D,H02P,Y02E

Claim:
1. A method for shutting down a wind turbine, the wind turbine comprising: a power generator connected to a set of rotatable rotor blades via a drive train, a power converter comprising a generator side converter and a grid side converter separated by an intermediate DC circuit, and at least one of power dissipation and power storage means operatively connected to the intermediate DC circuit, wherein the method comprises: operating the wind turbine according to a first operating mode, wherein the first operating mode comprises a power control loop having feedback parameters indicating an amount of active power and an amount of reactive power supplied to an associated grid, and in response to a request to shut down the wind turbine, performing a controlled shutdown of the wind turbine in a second operating mode, wherein the controlled shutdown comprises controlling an output of the generator side converter using a power reference derived from a predefined generator torque-speed curve so that torque of the drive train has a constant direction, wherein the generator is connected to the associated grid during the controlled shutdown of the wind turbine and wherein the predefined generator torque-speed curve is not used during the first operating mode and the power control loop is not used during the second operating mode.