Wind turbinecontroller with pitch feedback control loop in partial load

The method of controlling a wind turbine that in operation generates a produced power output level and which is operated in accordance with a rated power output level, the method comprising:

• receiving a power reference signal in a wind turbine controller that defines a requested power output level lower than an available power level;
• determining whether or not the available power level is above or below the rated power level;
• if the available power level is below the rated power level, control the wind turbine to:
• setting a blade pitch of a rotor of the wind turbine to a pitch value based on the received power reference signal that causes the rotor to capture wind power that is approximately equal to the requested power output level;
• controlling the produced power output power level of the wind turbine to the requested power output level by adjusting a load torque provided to the rotor by a generator coupled to the rotor;
• and
• wherein the blade pitch of the rotor is further controlled by a pitch feedback control loop that modifies the pitch value based on a difference between the produced power output level and the requested power output level;
• and alternatively
• if the available power level is above the rated power level, control the wind turbine to:
• setting a generator speed and load torque provided to the rotor by a generator coupled to the rotor based on the received power reference signal to provide the power output level that is equal to the requested power;
• and
• controlling a the blade pitch of the rotor to controlling the produced power output power level of the wind turbine to the requested power output level by adjusting the pitch value of the rotor.

A controller for a wind turbine comprising:

• a processor and a memory including instructions that, when executed by the processor, cause the processor to
• receive a power reference signal that defines a requested power output level lower than an available power level;
• set a blade pitch of a rotor of the wind turbine to a pitch value based on the received power reference signal that causes the rotor to capture wind power that is approximately equal to the requested power output level;
• control the produced power output power level of the wind turbine to the requested power output level by adjusting a load torque provided to the rotor by a generator coupled to the rotor;
• and
• wherein the processor further cause a pitch feedback control loop to modify the pitch value based on a difference between the produced power output level and the requested power output level.

A wind turbine that in operation generates a produced power output level, the wind turbine comprising:

• a processor and a memory including instructions that, when executed by the processor, enabling the processor to receive a power reference signal that defines a requested power output level lower than an available power level;
• a pitch system for setting a blade pitch of a rotor of the wind turbine to a pitch value based on the received power reference signal that causes the rotor to capture wind power that is approximately equal to the requested power output level;
• a power system for controlling the produced power output power level of the wind turbine to the requested power output level by adjusting a load torque provided to the rotor by a generator coupled to the rotor;
• and
• wherein the processor further cause a pitch feedback control loop to modify the pitch value based on a difference between the produced power output level and the requested power output level.