Forward converter using a resonant auxiliary circuit to provide soft‐switching and reset the magnetic core

Abstract

In this paper, a new ZVT forward converter is presented in which the third winding of the forward converter is utilised to transfer power from the input to the output, recover the energy of the leakage inductance and snubber capacitance, and also provide ZVS condition for the converter switch. In the proposed converter, the main switch is turned ON and OFF under ZVS condition, and the auxiliary switch operates under ZCS condition. Besides, all the diodes are turned OFF under ZCS condition, and their reverse recovery losses are alleviated. Moreover, in the proposed converter, the voltage stress of the auxiliary switch is limited to the input voltage. As a result, the efficiency is improved. Since both converter switches and the input voltage share the same ground, no isolated gate driver is required in the implementation of the introduced converter. Also, due to the almost flat efficiency curve of the proposed converter, it is suitable for applications where the load range is wide. The proposed converter analysis, operating principals and design considerations are discussed in this paper, and the converter performance is justified by the implementation results from a 240 W prototype converter.

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

“…Power converters are widely used in various instruments and electrical and electronic equipment. Currently, converters have a trend towards higher efficiency, higher power density, and higher reliability [1][2][3][4][5]. Depending on the circuit structure, the power converter can be divided into a non-isolation or an isolation structure.…”