Study on Control Strategy of Maximum Power Capture For DFIG in Wind Turbine System

This paper analyzes the stator flux oriented vector control theory for doubly fed induction generator, control strategy of grid connected based on speed feedback and the arithmetic of tracking the peak power independent of the turbine characteristics and air density are used in this system. a principle of power characteristic for variable speed wind power generation systems is first explained. To optimize the output power, a method of MPPT which is based on the variable step of the velocity is researched and analysed. According to the error of the output power, the reference of the speed for turbine is calculated and adjusted by the PI controller. At last the article gives the simulation result of this method, the result shows the validity. 110kw VSCF doubly fed induction generator wind power system is constructed in the laboratory, which realizes the decoupled control of the active power and reactive power for stator output and the control of maximum power point tracking.