Research on Variable Pitch Control Strategy for a Synchronous Wind Power System with Direct-drive Permanent Magnet

Taking synchronous wind power system with direct-drive permanent magnet as the research object, this paper built the model of the whole wind power system based on the mathematical model of each part. In the model, the difficulty for pitch control caused by strong non-linear and large moment of inertia of wind power system was taken into account. A combined pitch control method on the basis of fuzzy adaptive PID and fuzzy feedforward was designed and the algorithm was simulated. The simulation results show that when the wind speed is above rated wind speed, the control algorithm can effectively control the output of wind turbines. Finally, the control effect of the designed controller was compared with fuzzy controller and the traditional PID controller under the same wind speed conditions. Comparison results prove that when the wind speed is higher above rated wind speed, although, all of the three controllers can control the output of wind turbines, however, compared with the fuzzy controller and the traditional PID controller, the proposed algorithm has better stability and dynamic characteristics.