Suppression of Common-Mode Voltage Based on Space-Vector Modulation for Four-Level Hybrid Inverters

This paper proposes the operation scheme and control method for a four-level hybrid-clamped inverter based on a modified space-vector modulation to suppress the common-mode voltage (CMV). With the proposed technique, the CMV peak value is reduced to 17% of DC-link voltage, whereas the peak-to-peak ripple of the flying-capacitor voltage is kept at 8% of its reference. In comparison with the in-phase disposition (IPD) modulation, the total power losses in the proposed method are decreased by more than 20% at various modulation indices. The effectiveness of the proposed inverter operation has been verified by simulation results.