Modeling and Simulation of Seven-Level Cascaded H-Bridge Inverter Based Shunt Active Power Filter for Single-Phase Distribution System

In this paper, a single-phase Seven-Level cascaded H-Bridge (CHB) based Shunt Active Power Filter (SHAPF) based on simple controller is proposed. Synchronous Reference Frame theory (SRF) is used for reference source current extraction and to generate gating pulses for the SHAPF. The main aim of the CHB is to eliminate harmonics, improve power factor and reactive power compensation of the single-phase distribution system. 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 single-phase SHAPF is aiming to perform with accurate tracking performance under step changes in load currents and to provide good dynamic compensation. In this paper, SRF-PLL with Inverse-Park transformation is adopted for generating quadrature component of current. The performance of the control algorithm is tested and evaluated using MATLAB/Simulink.