Design of variable pitch-control system based on two-degree-of-freedom internal model control

Aiming at characteristics of large time delay, strong coupling and large disturbance, a two-degree-of-freedom internal model control(2DOF-IMC) is proposed for electric pitch servo system. The detailed model and response model of the variable pitch control system which composed of permanent magnetism synchronous motor (PMSM) is analyzed, and the disturbance of blade angle of attack which caused by relative wind speed is discussed. After principle analysis of traditional IMC and 2DOF-IMC, the IMC controller is designed. The simulation result shows the 2DOF-IMC has the ability to regulate the performance of position tracking and load disturbance inhibition independently, and is more effective than traditional IMC.