Mitigation of deep voltage sag utilizing switched autotransformer with RBHVC

A voltage sag compensator based on a switched autotransformer by RBHVC (random band hysteresis voltage control) is proposed in this paper, which can compensate the deep voltage sags. The traditional voltage sag compensators cannot compensate the deep and long-duration voltage sags. The advantage of proposed compensator in this paper is that it uses only one controlled switch per phase with no energy storages. Also the control scheme purposed here distributes the harmonic spectrum of the load voltage and reduces its total harmonic distortion (THD). Different voltage sag events have been simulated by MATLAB/SEVIULINK software. The results of simulations verify the ability of proposed method to mitigate deep voltage sag events.