Multi-degree of freedom optimization control for large inertia wind energy conversion system using model predictive approach

Smoothing output power and alleviating mechanical loads are two main control objectives for wind energy conversion system (WECS) above rated wind speed. Conventional control methods, such as PID, cannot handle and balance multi-objective control problems. This paper presented a multi-degree of freedom, multi-objective optimization control method using model predictive approach to solve these problems. Power smoothing and mechanical loads alleviating were both given consideration in objective function. Simplified linear model was established reasonably to reduce the calculated amount. The proposed control system had good dynamic performance, fluctuations of generator power and drive train transient loads are both reduced. Simulation studies were carried out to verify the effectiveness of proposed method. The proposed method is beneficial to lifetime of wind turbine and reliability of power system.