SHE-PWM control for asymmetrical hybrid multilevel flying capacitor and H-bridge converter

This paper presents a new asymmetrical hybrid voltage source multilevel converter controlled with selective harmonic elimination pulse width modulation (SHE-PWM) technique. The proposed hybrid multilevel converter combines the separate flying capacitor (FC) converter in series with an H-bridge converter with distinct DC voltage supply. The DC-link voltage of the FC is twice that of the H-bridge converter and the flying capacitor is regulated at voltage V_dc/2. The device-account is greatly reduced when compared with conventional multilevel converters for the same number of output voltage levels. The mathematical modules that describe the eight-level SHE-PWM waveform is developed and selected switching solution sets were presented. The performance of the converter under different loading conditions is also investigated through simulation study.