Dual hybrid power filter based on a nine-switch inverter

One of the most important power quality issues is related to current harmonics generated by nonlinear loads such as diode and thyristor front-end rectifiers. The hybrid power filter (HPF) mixes low power rating active filters with passive filters. Recently, some active power filter (APF) topologies based on dual converters configurations have been shown superior performance when dealing with highly nonlinear loads. Based on this fact, the goal of the paper is to present a novel dual HPF configuration based on the nine-switch inverter, which has two sets of three-phase outputs connected in series with two passive LC filters. Thus, it is expected that the proposed HPF presents an enhanced harmonic compensation capability with respect to the state-of-art APFs. Experimental results are presented for a dual HPF inverter prototype in order to demonstrate the effectiveness of the proposed topology.