A new control strategy for energy-saving dynamic voltage restoration

A generalized voltage restoration method is proposed. It can satisfactorily alleviate the phase angle jump and voltage waveform discontinuity associated with the energy-saving voltage restoration method used in the dynamic voltage restorer (DVR). The method takes into account the characteristics of the voltage sag magnitude and phase-shift that may appear at the load bus as well as the voltage amplitude injection capability of the injection transformer. Simulation results demonstrate the efficacy of the proposed method, thus paving the way for voltage sag mitigation using DVR at reduced cost