High-Efficiency SiC-Based PSFB DC-DC Converter Using Peak Current Control with Digital Slope Compensation for LV Battery Charging In EV Applications

This paper presents the design, implementation, and evaluation of a high-efficiency Phase-Shifted Full-Bridge (PSFB) DC-DC converter utilizing Silicon Carbide (SiC) MOSFETs for low-voltage (LV) battery charging in electric vehicle (EV) applications. The converter operates with Peak Current Mode Control (PCMC), enhanced by a digitally implemented slope compensation technique to ensure control loop stability, counter subharmonic oscillations and accurate current regulation across a wide load range. The use of SiC devices enables high switching frequencies operation with reduced conduction losses, contributing to improved efficiency and power density of converter. The hardware design utilizes a planar transformer with shim inductance to enable Zero Voltage Switching (ZVS) of the primary switches, thereby reducing switching losses and mitigating transformer flux imbalance. The secondary stage employs diode rectification, while the overall PCB layout is optimized to minimize parasitics and ensure reliable high-frequency operation. A 2.2 kW prototype was developed and tested, converting 320 V to 14 V with experimental validation performed using NXP S32E278 domain controller. The proposed control scheme demonstrates fast dynamic response, stable operation under varying load conditions. Additionally, the converter’s performance under both steady-state and dynamic conditions was simulated and validated using PSIM and LTspice environments. This novel work highlights the advantages of implementing digital Peak Current Mode Control (PCMC) using a domain controller, combined with SiC technology, for next-generation EV charging systems.