Study on control strategy for three-phase four-leg inverter power supply

This paper proposes a novel control strategy of a three-phase four-leg inverter power supply. In the synchronous coordinate, the control scheme with the output voltage differentiation as inside feedback loop is adopted, and the cross-channel coupling bringing from capacitance is eliminated by the capacitance current feed-forward, the decoupled control of three phase four-leg power supply is achieved. The proposed control strategy has been implemented on a 400 Hz, 1 kW three-phase four-leg power supply. The three-phase output voltage waveform is quite good, it also perform well with the unbalanced load.