Analysis and Design of a Half-Bridge Converter with Current Doubler for Auxiliary Power Modules in Electric Vehicles

Electric vehicles (EVs) demand highly efficient power management systems to enhance reliability and extend operational autonomy. Unlike traditional internal combustion engine (ICE) vehicles, which use alternators to supply low-voltage systems, EVs rely on DC-DC converters, commonly referred to as Auxiliary Power Modules (APMs). This paper presents the analysis, design, and experimental validation of a half-bridge converter with a current-doubler (HB-CD) topology tailored for APM applications. A generalized structure is proposed to support the parallel operation of multiple modules, aiming to mitigate current stress and reduce output ripple. A 3~kW laboratory prototype was implemented using two 1.5 kW modules operating in parallel, enabling interleaved operation and effective current sharing. Experimental results demonstrate the converter’s ability to maintain high efficiency, reaching up to 94.6 % under nominal conditions and 95.9 % under minimum input voltage operation, confirming the feasibility of the proposed topology for high-current automotive applications.