A Fuzzy-Logic Based Output Power Smoothing Method of WECS with Permanent Magnet Synchronous Generator using Inertia of Wind Turbine

Abstract

This paper presents a fuzzy-logic-based output power smoothing method of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG) using the inertia of wind turbine. The generator-side converter controls the generator torque of the PMSG, while the grid-side inverter controls the DC-link and grid voltages, respectively. For the generator-side converter, the torque command is determined by using the fuzzy logic. Inputs the fuzzy logic are the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and t he generator torque. By means of the proposed method, the generator torque can be smoothed and the kinetic energy stored by the inertia of the wind turbine can be utilized to smooth the power fluctuations of the PMSG, and the wind turbine's shaft stress is mitigated compared to a conventional maximum power point tracking (MPPT) control. Effectiveness of the proposed method is verified by the numerical simulations.