Enhancement of LVRT performance and alleviation of power fluctuation of DFIG wind turbine in DC microgrid by SMES

Recently, a doubly fed induction generator (DFIG) wind turbine has been extensively paid attentions as a renewable energy source in the DC microgrid. However, the inevitable problems of DFIG wind turbine are low voltage ride through (LVRT) due to the occurrence of faults as well as the power fluctuation. To overcome both problems, a superconducting magnetic energy storage (SMES) unit which is able to provide fast control of active and reactive power, can be used. This paper applies a SMES unit to enhance LVRT performance and alleviate the power fluctuation of DFIG wind turbine in the DC microgrid. The SMES circuit is mainly composed of the DC chopper. The PI controllers of DC chopper are used to control the exchange energy between the superconducting coil and the system. Simulation study using MATLAB/SimPowerSystems ensures the SMES control effect on both enhancing LVRT performance and smoothing power fluctuation of DFIG wind turbine.