Dynamic Duty Cycle Based Pulse Charging of Parallel Lithium-Ion Batteries for Electric Vehicles

Efficient and reliable battery charging is essential for applications including electric vehicles (EVs), renewable energy storage systems, and uninterruptible power supplies (UPS). Traditional charging techniques frequently depend on separate DC-DC converters for each battery, resulting in higher system costs, increased control complexity, and spatial limitations. This paper proposes a Dynamic Duty Cycle based Pulse Charging (DDCPC) technique for the simultaneous charging of multiple batteries using a single Buck converter. Complementary switching of battery side switches at 1 kHz ensures alternate and continuous energy delivery, while the Buck converter operates at 10 kHz to balance efficiency and switching losses. A closed loop control mechanism dynamically adjusts the converter’s duty cycle to maintain a constant inductor current, enabling efficient and balanced charge distribution based on each battery’s state of charge (SOC). The proposed method improves charge uniformity, and shortens total charging time. MATLAB/Simulink simulations validate the effectiveness of the DDCPC approach, highlighting enhanced performance.