Review of dynamic voltage restorer for power quality Improvement

Power quality has always been important for customers, but with increasing applications of electronic loads and controllers sensitive to the power quality, the subject has attracted renewed interest in recent times. Power quality encompasses several aspects: harmonics, over voltage, flicker voltage sags and swells, interruptions etc., lasting only a few cycles can cause significant damage for a manufacturing process and computer hardware installations. Voltage source converter based dynamic voltage restorer (DVR) can be used effectively for mitigation of voltage sag and swells. This paper presents the operating principle, power circuit topologies, mathematical modeling, control philosophies and applications of DVR for power quality improvement along with systematic review of published literature.