High performances reference current generation for shunt active filter under distorted and unbalanced conditions

This paper presents new control strategy without PLL for shunt active power filter. It is based on a modified version of the p-q theory and on high performance selective band pass filters (SBPF), used for the harmonic isolation and suitable under any disturbed and/or unbalanced conditions. The proposed SBPF is theoretically studied under unbalanced and distorted three-phase electrical signal conditions. We more particularly examined the choice of the filter parameters according to dynamic response criteria. Two SPBFs are used to generate the reference currents for simultaneously the harmonics positive and negative sequences and the reactive power compensation. Digital controller implementation is experimentally validated by "FPGA in the loop" prototyping using an EP1S80B956C6 ALTERA FPGA target.