Comparison of three phase 4-leg shunt active power filter algorithms

Diversity of loads, resistive and inductive, monophase and three phase, balanced and unbalanced, developed with power electronics or not, led to power quality problems at consumer level. Problems that can be resolved locally with active or passive filters connected on loads terminal or global, by connecting in CCP (Common Coupling Point) a four wire three phase shunt active power filter (APF), solution chosen for this study. This paper presents a comparison between three control algorithms of a three phase 4-wire 4-leg active power filter. Comparative analysis was made based on the level of THD, power factor and unbalance level. The results were obtained by simulation in Matlab/Simulink software.