Effect of Three Phase Short Circuit Faults on the Performance of Wind Farms Employing Doubly-Fed Induction Generators

摘要

Nowadays electrical industry is facing challenge of meeting the ever increasing demand of electric power with minimum green house gas emissions. Amicable solution to this challenge is producing electric power using renewable sources. Over the years production of electric power by wind farms increased considerably because of its emission free characteristics. Wind farms employing back to back converters in the rotor circuit of doubly-fed induction generators (DFIG) have many advantages over other schemes. These converters carry nearly one fifth of the total power handled by the generators. This allows for economical operation with improved control in variable speed operations. But this converter operation is severely affected by short circuit faults that normally occur in power system networks. It is therefore essential to conduct short circuit fault studies on wind farms employing DFIG using back to back converters. A three phase fault occurring on the transmission line connecting wind farm to grid severely affects the operation of DFIG. The selection and set up of phase relays in power system networks are based on three phase fault analysis. In this paper simulation studies are carried out to identify the effect of three phase faults on the operation of wind farm employing DFIG.