Design and Analysis of a Hybrid Energy Storage System for a BLDC Motor in Lightweight Electric Vehicles

Internal Combustion Engine (ICE) vehicles are being replaced by electric vehicles to decrease fossil fuel depletion, pollution, and the effects of global warming. However, in electric vehicles, the primary concern is battery power consumption and lifespan, which affects the driving range. This study presents a hybrid energy storage system (HESS) comprising a lithium-ion battery and super capacitor array, designed and simulated in MATLAB/Simulink to enhance the range and performance of lightweight electric motorcycles powered by 2.5 kW BLDC motors. A 16-cell super capacitor module (3V, 3000F per cell) achieving 187F total capacitance was integrated with a 44.4V battery through a bidirectional DC-DC converter. Simulation results demonstrated that during startup acceleration, the super capacitor delivered peak currents up to 300A while battery current went to a steady value at 12A, reducing battery stress by 25 times. During variable torque transitions (half to full rated load), the super capacitor handled transient power peaks reaching 1700W, while battery power ramped gradually to 1150W. Most significantly, regenerative braking analysis revealed the super capacitor’s state-of-charge increased by 0.85% (from 97.6% to 98.45%) within two seconds, compared to only 0.035% for battery-only systems under identical conditions, representing a 24-fold improvement in energy capture efficiency. These results confirm that the proposed HESS effectively isolates transient load fluctuations from the battery, including regenerative braking capability, and providing a practical pathway toward extended battery lifespan and improved vehicle range in lightweight electric vehicle applications.