Enhancement of Power Quality in distribution network using DVR

Among the various power quality problems, voltage disturbances like sags are mostly concerned for the industrial and commercial electrical consumer as the numbers of advanced electrical and electronic equipment, such as variable speed drives, computers, PLCs, etc which are sensitive to voltage disturbances have increased. Custom power devices are normally employed to compensate these disturbances. One of the devices is Dynamic Voltage Restorer (DVR), which is used in both medium voltage and low voltage applications. Comparison of PWM based PI control and Hysteresis voltage control techniques for generation of switching pulses related to DVR are presented in this paper. The controller and compensation strategies aim for accurate compensation with fast response and low costs. The performance of these control techniques and achievement of desired compensation are confirmed by the results of the simulation using MATLAB/SIMULINK.