A Novel Secondary Side Series LCD Forward Converter with High Efficiency and Magnetic Reset

Abstract

A novel secondary side series LCD forward converter with a high efficiency and a magnetic reset is proposed in this paper. Compared with the traditional forward converter, the proposed converter can transfer excitation energy to the output terminal and achieve a reliable magnetic reset of the transformer with a better working efficiency. Moreover, the proposed converter realizes the low-voltage turn-on of the switch. The operating principle and energy transmission process of the proposed converter is explicitly analyzed. It was concluded that the optimal combined working mode was Lm-DCM, L1-CCM and L2-CCM. By analyzing the energy transmission mechanism of the proposed converter in the best working mode, the parameter design scheme of the proposed converter was obtained. Finally, a prototype was built. The simulation and experimental results are presented to verify the correctness of the theoretical analysis and the feasibility of the parameter design scheme of the proposed converter. At the same time, a comparison between the proposed converter and existing converters was conducted to demonstrate the best electrical performance of the proposed converter.

Keywords

• secondary magnetic reset
• excitation inductance
• the optimal operating mode
• energy transmission