Compensation of voltage sags and swells by using Dynamic Voltage Restorer (DVR)

The most important aspect for electrical engineering is power quality in recent year. Power quality problem is an event of abnormal voltage, current or frequency. Utility distribution networks experience from various types of disturbances. The major problems dealt here are the voltage sags/swells. Now the fast developments in power electronics technology have made it possible to mitigate power quality problems. Such as, dynamic voltage restorer can provide the most mercantile solution to compensate voltage sag/swell by injecting voltage in to the sensitive system. Dynamic Voltage Restorer is a series connected power electronics based device that can mitigate the power quality issues in the system and restore the load voltage to the pre-fault value. This review paper first gives an introduction to related power quality problems for a DVR and power electronics controllers for voltage sag/swell compensation. Afterwards the operation and elements in DVR is described by using new control strategy.