Modulation Schemes for Single-Phase B6 Converters With Two Asymmetrical Terminal Voltages

B6 converter uses six switches divided equally among three phase-legs. It has commonly been used as a three-phase rectifier or inverter, mostly under balanced conditions. Three-phase conversion is however not the only area, where B6 converter has been used. The same topology has been tried for single-phase power decoupling and single-phase ac-dc-ac conversion, where comparably lesser switches are needed. Although the basic modulation principle is still reliant on three modulating references for the three phase-legs, requirements imposed on the modulating references are different and usually asymmetrical. How these asymmetrical references should be formulated to meet various performance specifications of a single-phase B6 converter is the theme of this paper. Simulation and experimental results have been obtained for verifying the modulation schemes proposed.