Arash Khoshkalam - Department of Electrical Engineering, Hamedan University of Technology, Hamedan, Iran

Wind energy systems are increasingly being used in different distributed generation systems. Due to changeable nature of wind speed, selection of a suitable method as regards where the wind farm is, has a vital importance. Maximum power point tracking (MPPT) plays a critical role to improve the efficiency of wind energy conversion system (WECS). This Paper provides a comparison between common MPPT methods, including power curve, tip speed ratio (TSR), optimal torque control (OTC) and perturb & observe (P&O) . Then their effects on behavior of an islanded micro grid during and after overloading and short circuit fault has been investigated. Based on results in the literature, it is clear that OTC has better behavior than other methods and then TSR. After all because of methods nature, OTC, TSR, power curve and P&O has better performance respectively. The studied system is a micro grid with high share of renewable energy resources containing a WECS driven by wound rotor synchronous generator (WRSG), a synchronous diesel unit and some active and reactive loads.

Micro grid; Wind turbine; Wound rotor synchronous generator (WRSG); Maximum power point tracking (MPPT); Overloading; Short circuit fault