Application of Dynamic Voltage Restorer for Mitigating Voltage Sag

Abstract

Many researchers have been done to monitor and improve the quality of power. Many measures have been implemented and even we have gone so far in improving as well as maintaining the quality of power. Dynamic voltage restorer is a power electronic based device. It protects sensitive loads from the various types of disturbances of the power supply. The basic principle of DVR is to restore the voltage sag to a pre-sag value by injecting a desired value of voltage. Conventional DVR uses Sinusoidal Pulse Width Modulated Voltage Source Inverter. But in this thesis, Space Vector Pulse Width Modulation technique is used. The main function of VSC is that it converts the DC voltage which is supplied by the Energy Storage Unit into an AC form of voltage. The DVR power circuit uses step up voltage injection transformer, therefore a VSI with even a low voltage rating would result to be sufficient.
Keywords: DVR; Voltage Sag; Power Quality