Design of a Balanced Three-Phase Power Supply Soft-Switching Based on Single-Phase Inverter Power

To eliminate the negative effects caused by three-phase unbalanced distribution, a novel soft-switching system based on single-phase inverter is proposed. The system achieves three-phase equilibrium distribution by adjusting the power supply of the electric equipments. This paper presents a track strategy named regulating frequency to promise no impulse current, which means regulating the output frequency of the inverter to make the output voltage of the inverter synchronize with the grid voltage. Firstly, make the output voltage of the inverter synchronize with the voltage of original access phase, then switch the electric equipment to the inverter. Secondly, make the output voltage of the inverter synchronize with the voltage of alternative access phase, then switch the electric equipment to the alternative access phase to accomplish the soft-switching. MATLAB software and experiment are used to carry out verification for this system. The result shows that the impulse current is practically zero when the electric equipments are switching. The system achieves soft-switching.