Single-Phase 3-Level and 5-Level Boost Inverters without High-Frequency Common-Mode Voltage

This paper proposes two single-phase boost inverters that are capable of mitigating the high-frequency common-mode voltage (CMV). The conventional two-stage topology that consists of a frontend boost converter and a backend H-bridge inverter is restructured. While retaining the advantages of the conventional topology such as continuous input current and dynamic voltage gain, the proposed 3-level boost inverter achieves constant CMV without requiring any additional components. An extended 5-level boost inverter is also proposed by integrating another capacitor controlled by 4 switches to the 3-level topology. For the same inductor charging duty-cycle and inverter modulation index, the voltage gain of the proposed 5-level boost inverter is double compared to the 3-level counterpart. The operation of the proposed 3-level and 5-level boost inverters is comprehensively analyzed and verified by simulation results.