Hardware implementation of a three-phase active filter system with harmonic isolation based on self-tuning-filter

This paper presents the hardware implementation of a new control method based on an improved harmonic isolation for active filter systems. The harmonic generation is based on Self Tuning Filters for the harmonic isolation and on a modulated hysteresis current controller for the current control technique. This active filter is intended for harmonic compensation of a diode rectifier feeding a RL load. The study of the active filter control is divided in two parts. The first part deals with the harmonic isolator which generates the harmonic reference currents and is implemented into a Dspace DS1104 prototyping card. The second part focuses on the generation of the switching pattern of the IGBTs of the inverter by the modulated hysteresis current controller, implemented into an analogue card. The use of Self Tuning Filters instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the alpha-beta axis at high performances, without any Phase Locked Loop. The effectiveness of the new proposed method is verified by computer simulation and validated by experimental study.