Power Quality Improvement of Distribution Networks Using Dynamic Voltage Restorer

Abstract

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. Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure of end use equipments. One of the major problems dealt here is the power sag. Sensitive industrial loads and utility distribution networks all suffer from various types of outages and service interruptions which may result in a significant financial 1oss. To improve the power quality, custom power devices are used. The device considered in this work is DVR. This thesis presents modeling, analysis and simulation of a Dynamic Voltage Restorer (DVR) test systems using MATLAB. In this work, PI controller and Discrete PWM pulse generator are used for the control purpose. Here, different fault conditions are considered for linear as well as induction motor load. The role of DVR to compensate load voltage is investigated during the different fault conditions like voltage sag, single phase to ground, double phase to ground faults. In addition, the application of DVR to compensate the problem of starting voltage dip for induction motor is also investigated.