Resonant DC/DC Converters: Investigating Phase-Shift Control

Abstract

The paper presents an innovative approach to control the voltage of an LCL-T type converter at the output side against variation at input and load ports, utilizing a fixed-frequency phase-shift control scheme. The examination of the converter is performed employing a Fourier series method that takes into account the effect of n-harmonics. To assure high-frequency switches with a zero-voltage switching (ZVS) technique, the lagging pf mode is utilized. PSIM simulations were used to investigate the performance of a 300 W converter. With the minimal input voltage, all switches turn on with ZVS for all loading conditions, whereas the ZVS strategy loses by two switches when the voltage at the input is highest. The power loss calculations of each component are performed and presented in a pie chart. The findings of the experiments are presented and verified with theoretical and simulation results. It is demonstrated that for both input voltage and load fluctuations, a minor adjustment in pulse width is sufficient to keep the output voltage constant.