Voltage SAG/SWELL mitigation using AC chopper

A new topology is proposed here to compensate voltage sags in power systems. One of the major power quality issues encountered by industries is the voltage sag. To compensate sag, a new topology is designed without storage device. This sag adjuster is capable of compensating deep and long duration voltage sag. The sag adjuster of each phase derives power from other two phases. The sag occurring in single-phase is compensated by sag adjuster; it is realized with two ac chopper circuits. By controlling the firing angle of each ac chopper, the required voltage is obtained to compensate for the voltage sag. Simulation of proposed topology is done. The results are comply with IEC standard.