The yaw system of Mw class wind turbine can make the impeller align with the wind direction by rotating the engine room to achieve the maximum utilization of wind energy. Through the optimization control strategy of dynamic and static processes, flexible start and stop, clearance elimination between teeth and other functions, the unit can achieve less vibration and wear, and achieve the win-win goal of long life and low cost. system composition: The system consists of yaw frequency converter, br