Performance Comparison of VSI based Dstatcom and ZSI based Dstatcom in a Distribution System Network

Abstract

Power Quality problem in a system leads to various disturbances such as voltage fluctuations, transients and waveform distortions. Due to non linearity of load it leads to fluctuations in waveform. Modern industrial equipments produce distortion in load current and harmonic distortions. Present day power consumers are also aware enough regarding various Power Quality problems that lead to inconvenience. So engineers are also working in this field dedicatedly to improve the quality of power supply. One of the results of their research in this field is DSTATCOM (Distribution STATCOM) that performs various compensating functions in distribution systems. A Distribution Static Compensator is a Voltage Source Converter based device. It is connected in parallel with the system to be compensated. This device injects compensating response at PCC into the system. Various Power Quality issues like voltage sag, swell, harmonics, power factor are compensated by this device. In this work an attempt has been made to employ ZSI based DSTATCOM in a distribution network to improve the power quality level, further its performance has been compared with VSI based DSTATCOM in a distribution network in MATLAB/SIMULINK environment. The performance of DSTATCOM to improve THD level in source current, Power Factor Improvement and load balancing has been demonstrated in this work.