A Single-Phase to Three-Phase Power Conversion System with Reduced Switches and Improved Output Voltages

In this paper, a topology is proposed to convert a single-phase power supply to independent three phases so that balanced or unbalanced, linear or non-linear three-phase loads can be operated. It can be used in places, e.g., rural areas, where only a single-phase power supply is available. The converter consists of four legs: one rectifier leg to generate a DC-bus voltage; two phase legs to generate two independent phases to form balanced three-phase voltages together with the single-phase power supply and one neutral leg to generate a neutral point, which is common to the single-phase supply and the two phases generated. Decoupled control strategies are developed to make sure that the current drawn from the single-phase supply is sinusoidal and in phase with the supply voltage, the generated phase voltages contain low voltage harmonics even when the load is non-linear and the neutral point is maintained stable. Simulation results are provided to illustrate the excellent performance of the system.