`VOLTAGE SAG MITIGATION USING DYNAMIC VOLTAGE RESTORER

Abstract

Now a day power quality problem has become a major issue to deal with, in order to maintain quality
supply. Modern generation greatly depends on electrical energy for improving their life style. Modern equipment like
computers, electric motors etc. cannot run without electricity. In order to improve the performance, the equipment
demands quality supply. The power quality is affected by various factors of the electrical network. Power quality
problems such as voltage and frequency variation, harmonic contents affect the performance of electrical utility and
shorten its life time. Such problem has to be compensated to ensure the quality supply. One of the most frequently
occurring power quality problems in transmission network is voltage sag/swell. Such problems can cause heavy flow
of current reduces the life time of the equipment or can cause over voltage affecting the insulation level of the
equipment. Many modern custom devices are present in order to mitigate such problems. Among them, Dynamic
Voltage Restorer (DVR) is efficient and cost effective. In this paper, an overview of DVR and control scheme used to
control the DVR is presented. The simulation result with the proposed control scheme is also shown.