Voltage flicker mitigation using forty pulse voltage source converter based DSTATCOM

Abstract

With the universal grid integration of non-conventional energy and increased transmission of power to geographically inaccessible and rural areas over the period of time, the importance of enhancing the power quality at both the generation end and distribution end has increased substantially. But, the greater degree of use of non-linear loads and other external factors has led to the increased deterioration in power quality and introduction of unacceptable phenomena like harmonics, voltage sags and swells and induced voltage flicker. Voltage flicker pose a serious threat to power system. It is characterized by sharp change in voltage level accompanied by increase in harmonic distortion and is common in highly inductive loads like electric arc furnace. Though it lasts for the shorter interval of time, it is regarded as potentially hazardous for load as well as supply, jeopardizing the safety of electric devices connected to the power system. For this reason its mitigation is of utmost importance. For mitigation of this phenomenon, FACTS devices like DSTATCOM are extensively used in power industry. This thesis presents the impact of using conventional six-pulse and multi-pulse converter circuit configured DSTATCOM. In the proposed work a non-conventional ten-pulse inverter is simulated which is non-integral multiple of six. Then a forty-pulse inverter is designed using ten-pulse inverter as the building block. The effectiveness of proposed DSTATCOM for flicker mitigation is established using MATLAB/SIMULINK.