Performance Analysis of Cascaded Multilevel Inverter Based DSTATCOM

In this paper, a single-phase Seven-Level and Five-Level cascaded H-Bridge Inverter (CHB) based Distribution Static Compensator (DSTATCOM) is presented. A simple control algorithm based on inverse park PLL was proposed for both five-level and seven-level inverters. Synchronous Reference Frame theory (SRF) as control algorithm is used for reference source current extraction and to generate gating pulses for the DSTATCOM. The main aim of the CHB is to eliminate source current harmonics and improve input power factor in the single-phase distribution system. The multilevel inverter has some limitations in its applications due to high complexity and size. The proposed control algorithm has two components, converting the load current into stationary reference frame coordinates and estimation of peak amplitude of load currents. Hence, a simple and reliable controller with ease of implementation was developed. The algorithm for singlephase DSTATCOM is aiming to perform with accurate tracking performance under step changes in load currents and to provide good dynamic compensation. In this paper, InversePark transformation is adopted for generating quadrature component of current because of its dynamic performance under all varying conditions. The performance of the control algorithm is tested and evaluated using MATLAB/Simulink.