Simulation research on the control strategy of three-phase four-leg inverter

The four-leg inverter is able to provide simultaneous power supply for three-phase or single-phase load with symmetrical voltage and constant frequency. The prerequisite is that the four-leg inverter must be controlled appropriately, so the synchronous rotating control strategy based on the decomposition sequence is proposed in this paper. Firstly, the inverter´s mathematical model was given. Based on the model, control variables are decomposed in the novel decomposition sequence algorithm, and the forward-feed decouple method is adopted in the control system; Secondly, control system parameters are determined. Finally, by experimental results and comparatively analysis, the proposed control method is verified valid and is superior to Proportion-Integration control strategy on traditional synchronous frame.