Comparison between Isolated and Grid Connected Dfig Wind Turbine

The conventional resources of energy are depleting .These resources will be finished after few years, therefore new sources of energy will be required which does not use fossil. To overcome these problems in recent years, wind energy has become one of the most important and promising sources of renewable energy, which demands additional transmission capacity and better means of maintaining system reliability. To harness the wind energy efficiently the most reliable system in the present era is grid connected doubly fed induction generator. The rotor side converter (RSC) usually provides active and reactive power control of the machine while the gridside converter (GSC) keeps the voltage of the DC-link constant. The GSC can supply the required reactive current very quickly while RSC passes the current through the machine resulting in a delay. Both converters can be overloaded, so the DFIG is able to provide considerable contribution to grid voltage support during short circuit periods. This paper deals with the introduction of DFIG, AC/DC/AC converter control and finally the SIMULINK/MATLAB simulation for isolated IG as well as for grid connected DFIG and corresponding result and waveforms are displayed.