Enhanced Electric Vehicle Charging Using a GaN-HEMT-Based Buck Converter with a Resonant Gate Driver for Closed-Loop Operation

The growing demand for efficient and compact electric vehicle (EV) chargers has led to the adoption of gallium nitride high electron mobility transistor (GaN-HEMT) as a switching device used in converters. By leveraging the high switching frequency and superior characteristics of GaN devices, the proposed RGDC minimises gate power loss while ensuring high efficiency and thermal stability. The integration of a feedback-based closed-loop mechanism results in dynamic regulation of the switching signal, which is crucial for voltage stability and ripple suppression in EV charging environments. Simulations in LTspice validate the design, revealing substantial performance enhancements such as a reduction in output voltage overshoot from 39.06 V to 23.86 V, an improvement in average inductor current from 1.219 A to 1.749 A, and a significant decrease in gate current from 1.6 A to 80 mA. The converter achieves a peak efficiency of 94 % in closed-loop operation, compared to 75 % in open-loop operation, with corresponding reductions in power loss across various load conditions. These outcomes demonstrate the proposed closedloop operation of RGDC's potential to support compact, energyefficient, and thermally robust EV charger architectures.