Control Strategy of a 0.5 MVA/1 MJ SMES Based Dynamic Voltage Restorer

A 0.5 MVA/1 MJ superconducting magnetic energy storage system based dynamic voltage restorer (DVR) is considered to be developed in the near future. The topology and control strategy are illustrated in this paper. To ensure full time utilization of the device, the DVR will not only compensate voltage deviations during voltage sag, but will also work as a harmonic and reactive power compensator to compensate both voltage and current harmonics as well as the reactive power of the downstream load in normal operation. Simulation results verify the efficacy of the proposed control strategy.