Mitigation of Voltage Sag at Oil Refinery Having Induction Motor Load using Dynamic Voltage Restorer

Power quality is one of major concerns in the present era. It has become important, especially, with the introduction of sophisticated devices, whose performance is very sensitive to the quality of power supply. One of the major problems dealt by oil refinery industries constituting induction motor loads is the voltage sag. Depending on the depth and the duration of the voltage sag, the motor speed may recover to its normal value as the voltage amplitude recovers. Otherwise, the motor speed may slow down and the torque exerted by the motor could not supply the load. This paper presents the response of induction motors to voltage sags through MATLAB Simulation. To overcome this problem, Dynamic Voltage Restorer (DVR), which is the most efficient and effective modern custom power device used in power distribution networks is used. Various conditions of sag is simulated and the results are presented in this paper. The performance of DVR is analyzed in this paper.