Method of shutting down a wind turbine

A wind turbine comprising:

• a rotor with a plurality of blades;
• a generator system coupled to the rotor;
• and
• a control system, wherein the control system is configured to:
• operate the generator system to generate electrical power and apply a load torque to the rotor;
• control the electrical power generated and the load torque with a power reference signal;
• determine that a shutdown of the wind turbine is required;
• in response to determining that the shutdown of the wind turbine is required, change the power reference signal so as to increase the electrical power generated and the load torque, the increased load torque slowing the rotor, wherein a pitch of the plurality of blades is kept substantially constant as the power reference signal changes;
• determine that a speed of the rotor has reduced below a threshold;
• and
• in response to determining that the speed of the rotor has decreased below the threshold, change the pitch of the plurality of blades to further slow the rotor.

A non-transitory computer-readable storage medium having computer-readable program code embodied therewith, the computer-readable program code executable by one or more computer processors to perform an operation for a wind turbine, the wind turbine comprising a rotor with a plurality of blades and a generator system coupled to the rotor, wherein the operation comprises:

• operating the generator system to generate electrical power and apply a load torque to a rotor;
• controlling the electrical power generated and the load torque with a power reference signal;
• determining that a shutdown of the wind turbine is required;
• in response to determining that the shutdown of the wind turbine is required, changing the power reference signal so as to increase the electrical power generated and the load torque, the increased load torque slowing the rotor, wherein a pitch of the plurality of blades is kept substantially constant as the power reference signal changes;
• determining that a speed of the rotor has reduced below a threshold;
• and
• in response to determining that the speed of the rotor has decreased below the threshold, changing the pitch of the plurality of blades to further slow the rotor.