Homo polar components compensation by a Zig-Zag transformer in a b-shape hybrid active power filter

This paper presents a b-shape hybrid active power filter and an active electromagnetic filter (AEMF) to compensate harmonic and homo polar (zero-sequences) components of the source currents. A three-phase Zig-Zag transformer and a half-bridge single-phase inverter form active electromagnetic filter. The homo polar components compensation is independent of location of the Zig-Zag transformer due to using of the AEMF. A parallel passive filter tuned in 5^th order of harmonic and a half-bridge three-phase inverter form a b-shape hybrid active power filter. The AEMF and parallel passive filter reduce power rating of the inverter employed in bHAPF effectively. The AEMF and the bHAPF are supplied by a common DC-Link. Therefore, the inverter of the presented HAPF has four legs. The principles of this topology, and the resonance-damping characteristics of the proposed topology are analyzed in detail. The HAPF has been simulated and the simulation results are provided to validate effectiveness of the proposed topology and the design considerations.