A Comparative Power Quality Study of DFIG and PMSG Based Wind Energy Conversion System

Wind Energy Generation Systems (WECS) are confronted with increasing demands for power quality and harmonic distortion control. With the advances in power electronics technology, the rapid growth of variable speed WECS is now witnessed. However, the power quality still remains an important issue to be addressed thoroughly by researchers. This paper presents a comparative study on grid connected WECS having two different Wind Turbine Generator Systems (WTGS) using DFIG and PMSG. Both WTGS systems are connected to power grid through conventional back to back converters and Unconventional Power Electronic Interface (UPEI) in different cases. Four cases are compared examining the effect of proposed unconventional power electronic interface on both WTGS systems. Transient simulations are carried out under the condition of sudden short circuit disturbance and the performance of both systems is compared for active power, reactive power and speed control. The comparison also aims to present in a thorough and coherent way the aspects of power quality in terms of reduction in Total Harmonic Distortion (THD) at various fault locations and buses. All the simulations are made in Matlab/Simulink. Key-Words: Wind Energy Conversion System, Wind Turbine Generator System, Unconventional Power Electronic Interface, Power Quality, Total Harmonic distortion.