Parallel AC-AC three-phase with shared-leg converters

Two parallel ac-ac three-phase to three-phase with shared-leg converters are proposed in this paper. They are composed of two parallel three-phase rectifiers, two parallel three-phase inverters, where each group of rectifier and inverter sharing one or two legs, and one or two dc-links. Suitable modelling and control strategy of the system are developed. Compared to the conventional three-phase to three-phase dc-link converter, the proposed topologies permit to reduce: the current and power ratings of the power switches, total harmonic distortion (THD) of grid current and, the semiconductor and dc-link capacitor losses. Simulated and experimental results are also presented in order to validate the analyses.