A repetitive-based controller for a single-phase shunt active filter

This paper presents a new repetitive-based controller for a single-phase active filter to compensate reactive power and current harmonic distortion. The topology selected for the active filter consists of a single phase full-bridge voltage source inverter (VSI). The repetitive scheme consists on a negative feedback array of a single delay line plus a feedforward path, and it is aimed for the compensation of odd harmonics only. The key observation here is that there exists an equivalent expression for such a repetitive scheme in terms of a bank of resonant filters tuned at odd harmonics, yet another technique of harmonic disturbance mitigation based on the well known internal model principle. It is shown that the repetitive scheme has a simple implementation, in contrast to the bank of resonant filters approach. The proposed control scheme has been experimentally tested in a 1.5 kVA prototype and the results are presented