Self-Sensing Closed-Loop Pitch-Speed Control for Reduction of Wind Turbine Structural Loads during Turbine Emergency Stop

摘要

In order to prevent the wind turbine rotor blade(s) from sticking in the event of an encoder failure, an innovative solution, a self-sensing closed loop speed control scheme for specially designed Interior Permanent Magnet Synchronous Motor (IPMSM), is presented. Compared to state-of-the-art self-sensing methods, this control scheme provides up to 3 times rated torque from standstill even in case of grid faults in order to ensure a safe and high performance movement into the feathering position under all operation conditions of the turbine. Bladed simulations are showing an additional benefit of the self-sensing concept: The closed loop speed control scheme also ensures a blade load independent, synchronous movement of all three blades. This paper also presents the results of the GH Bladed based on a case study to demonstrate the influence of pitch position incoherence on the turbine structural loads during the feathering run. It finally introduces a standardized performance qualification process for the pitch actuators which guarantees a robust and reliable performance of the pitch actuators in the field, covering the whole turbine life.