Experimental Investigation-Based Practical Design Guideline of 50 kW Three-Phase AC/DC Converter for Fast Charger Power Module

The demand for high-power dc fast chargers has increased to reduce electric vehicle charging time, driving the active adoption of power modules to enhance charger power capacity. As the power capacity per module increases and the number of parallel modules decreases, the overall system volume and cost are reduced. Thus, the development of high-power modules has become increasingly important. Therefore, this article provides practical guidelines for implementing a 50 kW three-phase power factor correction (PFC) converter, commonly used as an ac–dc converter module in dc fast charger. A quantitative analysis of the volume, performance, cost, and efficiency of different filter types for a three-phase PFC designed under identical conditions is conducted, providing selection criteria based on design priorities. Additionally, a stable startup method using feedforward compensation is proposed to regulate the inrush current. The effects of gain variations on steady-state and dynamic characteristics, along with current total harmonic distortion (THD), are analyzed. Furthermore, hardware implementation and thermal design considerations for the reliable parallel operation of SiC mosfets are presented. As a result, the implemented three-phase PFC converter achieves a maximum efficiency of 98.65% and an efficiency of 97.10% under full-load conditions, while maintaining a current THD within 5% in the primary operating range.