Phase-Shifted LLC Resonant DC-DC Converter for Battery Charging Application

This study presents the design of a phase-shifted DC-DC series-parallel full bridge resonant converter (PSFB-LLC) for battery charger application. The proposed converter is controlled by phase-shift pulse width modulation that switches the full bridge inverter connected with a resonant tank; it is equipped with an isolated transformer (high frequency) and backed with a battery for energy transfer and for achieving zero current switching (ZCS) at all the primary active switches. The magnetizing inductance was implemented in parallel with the phase-shifted angle to improve the capacitance of the tank and facilitate the achievement of ZCS for the active switches. The analysis and evaluation of the proposed system was done using MATLAB/SIMULINK software for a 48V 150 Ah lead-acid battery and selected results were adopted to prove the system validity. As a result, the state of charge (SOC) is increasing during charging, thereby confirming the suitability of the developed converter for use energy storage systems.