Power Control Research Of Direct-Drive Permanent Magnet Synchronous Wind Turbines

In the fast developing modern society, the demand for energy is growing and environment is extremely deteriorated, so making use of clean and renewable energy has become a vital human subject. Wind energy attracts attentions all over the world in recent years, for its free-pollution, rich-resources, no side effects and other advantages. Northwest China is rich in wind energy as well as costal areas. Development of wind energy has broad prospects and huge potential. This paper main studies the active power control, with direct drive permanent magnet synchronous wind turbine as object.Firstly, the major components of the permanent synchronous wind turbine are analyzed to explain the working principle of the parts and significance in the system on the mathematical model. After describing dual PWM model, establish the motor control strategy both in motor side and grid side. Meanwhile, on the basis of fuzzy control, smith compensation method is proposed depending on wind turbine pitch system. In order to improve the impact to generator output power from varying wind, smith predictor&fuzzy controller is designed. At the same time, according to the principles of the voltage vector control, the paper establish double closed-loop motor power control strategy including power-loop and inner current-loop. Through designing sliding controller and online self-tuning quasi-sliding controller instead of the traditional PI control, well suppressed power fluctuations.