Voltage Sag Compensation Strategy Using Dynamic Voltage Restorer for Enhance the Power System Quality

Abstract

Voltage sags associated with faults in transmission and distribution systems, energizing of transformers, and starting of large induction motor are considered as most important power quality disturbances (PQD). The most of the industries uses the power electronics conversion and switching for manufacturing and processing. These technologies are needs high quality and reliable power supply. Not only the industries, but also the electric power utilities and customers are becoming increasingly anxious about the electric power quality. Sensitive loads such as digital computers, programmable logic controllers (PLC), consumer electronics and variable frequency motor drives need high quality power supplies. Dynamic voltage restorer (DVR) is a series connected power electronic based device that can quickly mitigate the voltage sags in the system and restore the load voltage to the pre-fault value. DVR is recognized to be the best effective solution to overcome this problem. The primary advantage of the DVR is keeping the users always on-line with high quality constant voltage maintaining the continuity of production. This paper describes the DVR operation strategies and control. Results of simulation using MATLAB/Simulink are demonstrated to prove the usefulness of this DVR design and operation to enhance the power system quality.