Synchronous Reference Frame Method with PLL and Hysteresis Current Controller for Three Phase Shunt Active Power Filter to Mitigate Harmonics Caused by Nonlinear Loads

Rapid growth of power electronic and smart technology used in the industry is one of the key challenges in energy sector. The most common cause of power quality issues in power system is the harmonics which generated by nonlinear loads. Harmonics produce power quality issues and harmful effect on the electrical distribution network. Thus, to improve the power system quality and reliability, it is important to suppress the harmonic distortion cause by nonlinear loads. Traditional passive filters are commonly utilized in the industry but due to its limitation in compensation and production of resonance condition, active power filters are considered the most feasible solution. This study introduces a new design control strategy for Shunt Active power filter (SAPF) using synchronous reference frame (SRF) method for reference current generation, phase locked loop (PLL) and hysteresis current controller to mitigate the harmonic in a three phase distribution system. The design was modelled and simulated using MATLAB/Simulink. The study used IEEE Standard 519-2014 in compliance with the recommended limits of harmonics distortion. A three phase electrical distribution system was modelled and simulated for both balance and unbalance load condition to determine the harmonic distortion caused by nonlinear loads. The proposed SAPF was then connected parallel to the main distribution network to mitigate the harmonics presence in the system. The simulation results validates that the SAPF using SRF with PLL and hysteresis current controller was capable to extract the harmonic currents and generate a compensating current that will be injected back to the line to mitigate the harmonic distortion for both balance and unbalance load condition. Moreover, the results demonstrate that the individual harmonic current distortion are kept within the limit and acceptable harmonic values recommended as per IEEE standard.