High performance 500 W, 100 kHz isolated phase-shift full-bridge DC-DC converter using SiC MOSFET for efficient battery charging

Purpose This paper aims to present a highly efficient DC-DC converter for battery charging application. The SiC MOSFET-based phase-shift full-bridge topology with synchronous rectification is proposed to enhance the performance and efficiency of the converter by minimizing switching and conduction losses. Design/methodology/approach The converter design includes the implementation of a full-bridge topology on the primary side of a high-frequency transformer, using zero voltage switching (ZVS) techniques to reduce switching losses and improve efficiency. The secondary side uses synchronous rectification to enhance conversion efficiency and reduce conduction losses. A 500 W prototype was developed for experimental validation. Thermal analysis was conducted using a thermal image camera to assess the thermal distribution and heat dissipation under different load conditions. This experimental setup of the converter operates at 100 kHz frequency, with an input voltage of 60 V and an output voltage of 24 V, allowing the transition between 10 A and 40 A. Findings The use of SiC MOSFETs and ZVS techniques significantly reduces switching losses, while synchronous rectification minimizes conduction losses, achieving high conversion efficiency. Thermal analysis shows effective heat dissipation and manageable thermal distribution, which contributes to the system’s overall reliability. Research limitations/implications These outcomes address some of the challenges which are potentially reducing efficiency at low-power operation by achieving constant ZVS during light-load condition. Also, increasing number of switches makes the circuit complex and increases sensitivity to parameter variation. Furthermore, achieving leakage inductance of transformer design, even a small variation affects the performance of ZVS, leakage inductance, efficiency and system reliability. In such cases, an addition of inductance (L1) placed at the primary side of the converter helps to maintain reliable ZVS and balance the transformer leakage inductance which remains in practical limitation of converter design. Originality/value This research gives a novel power conversion solution that maximizes efficiency through innovative techniques like ZVS and synchronous rectification. Also, this study provides reliable performance and thermal management for modern battery charging systems. This significantly contributes for advance battery charging.