A Wide Input Five‐Level Inverter With Hybrid PWM‐SPWM Modulation

ABSTRACT Nonisolated inverters have the advantages of high power density, high efficiency, and low cost. However, the traditional nonisolated full‐bridge inverter has an output AC voltage amplification lower than the DC input voltage and suffers from leakage current problem. To address this problem, a nonisolated five‐level inverter with boost function is proposed in this paper. The inverter has the following features: (1) The leakage current can be theoretically eliminated due to the inherent common ground between the input and the output. (2) Due to the embedded switched capacitor circuits in the full‐bridge inverter, the proposed inverter achieves a higher voltage gain and is suitable for the applications with a lower dc input voltage. (3) A hybrid modulation strategy has been introduced for the proposed inverter, which ensures the continuity of the input currents and reduces the ripple of the input current when the DC input power is superimposed. The working principle, modulation strategy, and power loss of the proposed inverter are analyzed in detail. The experimental results verify the feasibility of the theoretical analysis and the excellent performance of the proposed inverter.