Simulation model of three phase dynamic voltage restorer for voltage compensation

摘要

Power quality is a big problem due to the increase in modern sensitive loads which are connected to the distribution network. One of the major problem dealt in this paper i.e. the voltage sag. This problem is very severe for the industrial areas as it can effect on malfunctioning of several sensitive electronic equipment's and devices. Dynamic Voltage Restorer (DVR) can be solution for this problem, as DVR is having ability to inject voltage automatically. It is a custom power device (CPD). DVR is connected in series with the electrical network to improve voltage disturbance in the electrical power system. For this purpose a repetitive controller technique has been used in the control system of the DVR. This helps to compensate for power quality problems which are created due to various reasons such as voltage sag and harmonic voltages. This control system contains a feed forward term, used to improve the transient response and a feedback term, used to enable zero error in steady state condition. This paper proposes to verify results given for a line to line fault. All results are shown and analyzed in MATLAB software. Results in the simulation shows that, the repetitive control technique works effectively and gives good improvement in voltage quality problems.