An Improved Three - Level Zero-Voltage and Zero- Current DC-DC Converter

An Improved Three - Level Zero-Voltage and Zero- Current DC-DC Converter

In this paper, after investigation of a conventional converter, a zero-voltage and zero-current pulse-width modulation converter is proposed. Due to the fact that the single power MOSFETs and IGBTs have lower switching loss and simpler drive circuit than the other module series, the converter size and its power loss decrease with respect to the other 3-phase topologies by using single power switches. Also, the soft switching is used for decreasing the power loss in this structure. For optimum use of ZVS (zero voltage switching) and ZCS (zero current switching), a combination of IGBT and MOSFET is presented. IGBT has low turn off loss and MOSFET has low capacitive loss. As a result, IGBT is suitable for ZVS switching and MOSFET is suitable for ZCS switching. A simple and low volume circuit is used at the output part for improving the stability. Finally, a simulation is carried out by PLECS software for evaluation of the proposed converter. The simulation results confirm the converter high efficiency and high stability at the output voltage.