Comparative Study of Direct and Indirect Current Control Algorithms for Shunt Active Power Filter

This paper presents a study on the development and simulation of two current control algorithms for a single-phase Shunt Active Power Filter (SAPF) operation. These current control algorithms are developed using two control strategies namely as direct and indirect current control strategies. Both current control algorithms are called Direct Current Control (DCC) algorithm and Indirect Current Control (ICC) algorithm. The operation of the SAPF using DCC and ICC algorithms are analysed in MATLAB/Simulink; to determine which current control algorithm is capable to boost up the steady-state performance of the SAPF in compensating harmonic currents. This work considers two cases of study. The first one is to study the performance of the SAPF under different percentages of full-load current, whilst, the second case is to study the performance of the SAPF when it is connected to different types of non-linear load. The SAPF performance is assessed by analysing the Total Harmonic Distortion (THD) value of instantaneous supply currents. From simulation results, it can be claimed that the SAPF using the DCC algorithm inherits better performance (in compensating harmonic currents) than using the ICC algorithm. Selected simulation results are presented to verify the hypothesis.