Research on high efficiency LLC resonant converter with constant frequency and phase shift control

Abstract

LLC resonant converter often leads to a larger number of primary side conduction loss ,in order to obtain high voltage gain over a wide range of inputs. This article proposed that a design scheme of digital charge for LLC resonant converter with constant frequency and phase-shifting control. It carry out with the specificity analysis and optimized design parameter of the LLC resonant converter. The LLC resonant converter is based on the DSP chip TMS320F28033 as the control core，and the paper analyzes the software implementation process of the scheme. Finally, a prototype of 350 V~500 V input and 200 V/5 A is designed, and the feasibility of the design is verified by simulation and experiment, it is proved that the design has a smaller primary conduction loss and the work efficiency is over 92% in the full load range.

Keywords

• LLC resonant converter
• constant frequency and phase-shifting
• smaller primary conduction loss
• full load range