A fuzzy-based output power smoothing of WECS using short-term ahead prediction of wind speed

This paper presents a fuzzy-based output power smoothing method for a wind energy conversion system (WECS) using short-term ahead prediction of wind speed. The WECS is based on a permanent magnet synchronous generator (PMSG) and transmits its electrical power to an AC grid through an IGBT pulse-width modulation (PWM) converter. The power converter controls the torque of the PMSG according to the torque command, which is determined by using the fuzzy logic. The inputs of the fuzzy logic are the predicted wind speed and the difference between the wind turbine torque and the generator torque. By means of the proposed method, the generator torque is smoothed and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the output power fluctuations of the PMSG. In addition, the wind turbine´s shaft stress is mitigated compared to a conventional maximum power point tracking (MPPT) control. The effectiveness of the proposed method is verified by numerical simulations.