Five-Level Cascaded H-Bridge MLC-Based Shunt Active Power Filter for Active Harmonics Mitigation in Distributed Network

This paper presents an investigation on mitigation of current harmonics, using Cascaded H-bridge Multilevel Converter (CHB-MLC)-based Shunt Active Power Filter (SAPF). Development and analysis of SAPF for harmonic compensation in distribution network for power quality improvement has been discussed. In the proposed work, transformer-less CHB MLC is used which reduces weight and cost of the system. Moreover, a novel controller based on average power method is adopted for generation of compensation active filter current. In order to generate switching signals, multi-carrier Alternate Phase Opposition Disposition (APOD) - Pulse Width Modulation (PWM) schemes are used. The proposed CHB-MLC SAPF reduces the source current THD below 5%. The results are simulated in MATLAB/Simulink and demonstrate the effective mitigation of current harmonics with APOD-PWM schemes. Opal-RT OP4500 real-time digital simulator is used to validate the proposed scheme under different steady state and transient conditions.