Circulating resonant current between integrated half-bridge modules with capacitor for inverter circuit using SiC-MOSFET

摘要

A design for the inverter circuit configuration of integrated half-bridge modules with a focus on the circulating resonant current is clarified in this paper. Although this configuration has the advantages of small DC-side stray inductance, an analysis of the equivalent circuit suggests that a DC-side capacitor current increases depending on the relationship between the resonant and switching frequencies. This fact will lead to an increase in the capacitor volume. The capacitor current was experimentally investigated at switching frequencies up to 100 kHz using a SiC-MOSFET. The experimental results demonstrated that the resonant current was remarkable when the resonant frequency was close to either the fundamental or the third harmonics of the switching frequency. By the proposed design, the increase in the capacitor current can be avoided.