Enhancement Of Fault Ride Through of DFIG Based Wind Energy Conversion System With The Application of SMES

-Doubly Fed Induction Generators (DFIGs)find a great deal of application among variable speed wind turbines because of their advantages like operation at variable speed, ability to produce active and reactive power in all the four quadrants, higher efficiency, and extracting maximum electric power at different velocities of wind with the help of speed variation of the rotor and the usage of converters having lower rating and thereby lesser overall cost. Till date DFIG based wind energy conversion systems (WECS) have reached 55% of the total installed wind capacity all over the world. Some of their drawbacks include weak fault ride through capability and high sensitivity to grid disturbances. Earlier wind turbine generators were not kept connected to the power grid during grid faults to avoid their damage. But as per the new grid codes the transmission system they must keep supplying power into the grid during fault. The paper proposes enhancement of the performance characteristics of a doubly fed induction generator with the implementation of SMES unit when voltage sag and swell are observed at the grid side. The proposed SMES configuration has VSC as the rotor side converter and dc-dc chopper as the grid side converter controlled by the hysteresis current control methodology and fuzzy logic rules respectively. MATLAB/SIMULINK software is used to perform simulation. Comparison of the results reveal the effectiveness of the proposed SMES controller in improving the overall performance of the WECS system under study. Keywords--Doubly Fed Induction Generator, Superconducting Magnetic Energy Storage, Fault Ride Through, Hysteresis Current Control, Fuzzy Logic Control.