Analysis & Mitigation of Voltage Imbalances Using PWM Based D-STATCOM for Industrial Applications

Abstract

-Voltage flicker is considered as one of the most severe power quality problems (especially in loads like electrical arc furnaces) and much attention has been paid to it lately. Due to the latest achievements in the semiconductors industry and consequently the emergence of the compensators based on voltage source converters, FACTS devices have been gradually noticed to be used for voltage flicker compensation.Voltage variations occur due to the small short circuit capacity in the distribution system. While starting of large motors there is a decrease in voltage due to requirement of inrush current. This decrease in voltage cause voltage flicker on other loads which are connected to same distribution system. This voltage flicker is very dangerous to sensitive loads due to this reason voltage flicker is one of the major power quality problem. This voltage flicker occurs due to non linear loads. A three phase four wire inverter systems is consider to compensate the voltage flicker.In this paper voltage flicker mitigation can be done by using FCTCR (Fixed Capacitor Thyristor controlled Reactor) and 3-φ, 4-wire inverter (STATCOM) of eight pulses. From the above two compensating devices STATCOM results show effective mitigation of voltage flicker..In extension we test whether the facts devices are capable of mitigating voltage flickers when a short circuit fault is applied and also under a load condition when Industrial drive like Induction Motor is connected Simulation results are shown in MATLAB software