An Enhancement of Dynamic Voltage Restorer for the Compensation of Voltage Sag by Using Induction Motor

Abstract

In this paper, an enhanced sag compensation strategy is proposed, which mitigates the phase jump in the load voltage while improving the overall sag compensation time. DVR’s are used to protect sensitive loads from the effects of voltage sags on the distribution feeder. Power quality has become a considerable issue in modern electrical power system. The extensive use of non linear load has increased the power quality problems such as stability of voltage. This paper proposes with improving the voltage quality of sensitive loads from voltage sags using a dynamic voltage restorer (DVR). The Induction motor is a three phase AC motor and is the most widely used machine. Induction motor characteristic features are- Simple and rugged construction and Low cost and minimum maintenance The voltage sags & swells affect the sensitive loads by nuisance tripping of fast acting relays. In order to overcome this power quality problem, dynamic voltage restorer (DVR) is used. The higher active power requirement associated with voltage phase jump compensation has caused a substantial rise in size and cost of the dc link energy storage system of DVR. The existing control strategies either mitigate the phase jump or improve the utilization of dc link energy by the following: 1) reducing the amplitude of the injected voltage or 2) optimizing the dc bus energy support. This enhancement can also be seen as a considerable reduction in dc link capacitor size for new installation. By using the simulation results The performance of the proposed method is evaluated.