A novel Z-source four-leg inverter with two independent four-wire outputs

This paper proposes a novel inverter for supplying unbalanced four-wire three-phase loads. The inverter has two three-phase outputs that operate with independent frequencies and amplitudes. Within each output, each phase can have independent voltage magnitude, but the frequency is the same for all phases. The topology is developed by adding an extra leg to a nine-switch converter. Moreover, it benefits from Z-source impedance network which provides more reliability along with voltage boost capability. Two carrier based modulation schemes are developed in the paper; one for the proposed topology and one for the case when Z-source impedance network is added. Simulation results verify the proper operation of the proposed topology.