Power Quality Enhancement of Cascaded H-Bridge Multi Level Inverter based Distributed-STATCOM by Standard and Intelligent Controllers

Abstract

The voltage source converters are to be designed with higher capacity for the purpose of maintaining the voltage profile constant by means of shunt compensators especially in distribution systems of medium voltages. Yet, designing converters of large rating imposes restrictions with respect to the stress and uniform distribution of stress in various devices is quite challenging in multi-level topology. The structure of cascaded arrangement of such inverters is very simple and expandable compared to other existing designs. This investigation aims to provide active filtering by the use of cascaded VSC particularly for 5-level and 7-level in distribution circuits for enhancing the quality of power. For experimental analysis a nonlinear rectification load using diodes (NLDRL) is considered and to abolish the Total Harmonic Distortion (THD) as well as to get a fairly reasonable power factor, the DSTATCOM (Distribution Static Compensator) is being used. The principal theory associated in the compensating process is the p-q philosophy. For validating the entire design by means of simulation MATLAB package is chosen.