Control for Diode-Clamped Three-Level Half Bridge converter

The control for a diode-clamped three-level half bridge converter is researched in this paper. The reasons for the input current distortion around the zero-crossing point of the input voltage based on the voltage zero-crossing detection control are analyzed in detail, and a hybrid control which combines the reference voltage feed-forward control with the feedback control is proposed to prevent the converter from the zero-crossing distortion mentioned. The feasibility of the control methods is verified by the simulation and experimental results.