Hojat Makvandi - Abadan oil refining company
Alireza Sadrania - Abadan oil refaining co

Nowadays, power quality is one of the major concerns of power systems, inappropriate quality ofdelivered power to consumers, make problems such equipment temperature increases, manyperformance of equipment, decrease efficiency and in result reduction of useful life spam ofequipment. On one hand, being inappropriate and power quality have adverse and negative effectson power system equipment like transformers, transmission line and compensation equipment and… that in this case, its result will be reduce effectiveness of power system. Between the parametersof power quality that has been noted in this article, the voltage sag has most important disorder forpower systems and consumers that in present paper suggested that used DVR (Dynamic VoltageRestorer) to remove this problem and also has been studied effect of DVR on voltage swell thatresults of simulation determined DVR in addition to beneficial effects on voltage sag, has favorableeffects on voltage swell. For simulation of this paper, we used MATLAB and its SIMULINKsoftware.Keywords: power

power quality, Voltage sag, Voltage swell, DVR