Comparative Study; Different Types of PWM Control Scheme in Three-Phase Four-Wire Shunt Active Power Filter (APF) Topology.

This paper focus on the comparative study for five commonly harmonics extraction methods through different types of pulse-width modulation (PWM) designed for three-phase four-wire shunt active power filter (APF). Three harmonics extraction methods consist of instantaneous reactive power theories (IRPT) which are p-q method, modified p-q, and p-q-r method, whilst two other methods are stationary reference frame and vectorial method. Two types of PWM namely; carrier and hysteresis current control were implemented for generating the injected current which are then feedback to the system for correction. The MATLAB/Simulink (MLS) is used to examine the comparison. The results revealed that continuous total harmonics distortion (THD) was establish when applying the hysteresis current control while the p-q-r method produce the preeminent performances in THD reduction with elimination of the neutral current harmonics.