Design and Implementation of a Soft-Switching Converter With High Step-Up Ratio

Abstract

The main purpose of this paper is the development of a DC/DC boost converter with high conversion efficiency. The proposed converter has high step-up ratio and is equipped with soft-switching technology. The main inductor used in the developed converter is the coupled inductor rather than the general inductor, therefore, the voltage conversion ratio of the converter can be improved, so that the high voltage conversion ratio characteristics of the converter power switch can be obtained within the same duty cycle. The developed converter is connected to a resonance branch circuit in the traditional high step-up converter, and is able to achieve zero-voltage switching (ZVS) with the main switch using a simple power switch signal control to reduce the switching loss caused by the traditional hard switching method in the high step-up converter, thereby improving converter efficiency. To verify the performance of the proposed converter, a circuit analysis on the high step-up soft-switching converter is first performed, and proceed to designing each component in the circuit. Then, the feasibility of the proposed converter is verified using the PSIM simulation software. Finally, actualize the proposed high step-up soft-switching boost converter with the TMS320F2809 digital signal processor (DSP), and verify that the main switch can indeed achieve zero-voltage switch, and that the conversion efficiency can reach as high as 91% when the developed converter is under full load of 300W, proof that the developed converter truly has excellent conversion performance.

Keywords

• Coupled inductor
• high step-up converter
• soft-switching converter
• zero-voltage switching (ZVS)
• digital signal processor (DSP)