Study on electric pitch control of induction motor with redundancy design

This paper presents a strategy of pitch control for a variable speed pitch-controlled wind turbine. Based on the analysis on the operating principle of electric pitch and the control strategy of servo control system, an electric pitch servomotor control system composed of an induction motor and its servo-drive controller is designed. A novel method of backup power supply management and redundant control is proposed in this strategy. Experimental results are presented to verify the effectiveness of the proposed control strategy.