Employing of Minimum Active Power Injection Strategy to Compensate Voltage Sag by DVR

In this paper, voltage sag is compensated by the DVR (Dynamic Voltage Restorer) in distribution systems. This device is applied between the sensitive load and the supply in order to inject voltage in series to correct the voltage sag. Subsequently, all the other various DVR compensation techniques in the distribution system are explained. Due to the restriction of the energy storage in DVR’s capacitors, it is essential to minimize the active power injected by the DVR. Thus, a minimum active power injection method is proposed to compensate the voltage sag. Performance of this method is evaluated under balanced and unbalance voltage sag in a distribution system.