Real time implementation of multilevel converter based shunt active power filter for harmonic compensation in distribution system

In past few years, with an increasing usage of power electronic devices in industries as well as distribution systems, the power quality is constantly depreciating. This paper investigation on mitigation of current harmonics, thereby improves power quality by using seven level cascaded multilevel converters based Shunt Active Power Filter (SAPF), which consists of transformer-less Multilevel Converter (MLC). The aim of this paper is development and analysis of SAPF for harmonics compensation in distribution system for power quality improvement. It also reduces weight and cost of the system. Instantaneous active and reactive power method (p-q theory) is adapted for generation of compensation active filter current where DC link voltage is regulated by PI controller. In order to generate gating signals, multi-carrier Alternate Phase Opposition Disposition (APOD) PWM scheme is used. The proposed CHB-MLC APF reduces the source current THD below 5%. The results are simulated using MATLAB/Simulink and demonstrates the effective mitigation of current harmonics with charge balancing APOD-PWM. The performance of proposed scheme has also been validated in Real-Time, using Opal-RT OP4500 simulator for non linear load and for high voltage distribution system.