DC side ripple current reduction method for three-phase boost inverter with mismatched output capacitors

The three-phase boost inverter is a differential inverter topology which can provide both boosting and inversion functions in a single power processing stage. If the switching frequency ripple current component is ignored, the DC side current of the three-phase boost inverter contains only a DC component when all three converter legs are identical. However, the capacitance values of the output capacitors can differ from their nominal values due to tolerance, temperature variation, and ageing. In this paper, it is shown that the mismatched capacitances of the output capacitors lead to a significant ripple current component at the DC side of the three-phase boost inverter. An input current AC component feedback method is proposed in this paper to mitigate such DC side ripple current components. The effectiveness of the proposed method is verified using simulation results.