Optimization of a direct-drive wind power generation system by using PMSG

This paper investigates the optimized model and the behavior of a variable speed wind energy conversion system (WECS) based on permanent magnet synchronous generator (PMSG). Models and equations that describe different components of the WECS are addressed and their implementations into PSCAD/EMTDC are described. There are different types of synchronous generators, but the PMSG is chosen because the elimination of gearbox and introduction of variable speed control would even further increase the availability of the system. The proposed model has a set of IGBT converter-inverter connected through a DC bus associated with the maximum power point tracking (MPPT) system. Three models for the converter-inverter set have been used and their performances have been compared. Simulation results show that the controllers can extract maximum power and regulate the voltage and frequency under varying wind conditions. The controllers show very good dynamic and transient performances.