Innovative Charging Solution Using a Three-Winding Transformer at the Battery Swapping Station

Electric Vehicles (EVs) are gaining global popularity as a sustainable solution to rising energy costs and environmental concerns. However, EV integration introduces power quality issues into the grid, coupled with the growing demand for accessible charging infrastructure. This work addresses these challenges by proposing a novel charging system for Battery Swapping Stations (BSS) that optimizes power utilization and improves grid stability. The proposed system utilizes a star-star-delta transformer to recover harmonic power from the tertiary winding, which is typically wasted as heat, to supplement fundamental power during battery charging. An interleaved bidirectional multiport converter ensures efficient power management, enabling optimized battery charging and discharging based on electrical parameters. Reactive power compensation via a Shunt Active Filter during peak hours further enhances voltage stability, power factor, and overall system efficiency. The system is modelled in MATLAB Simulink, with performance analyzed under peak and off-peak load conditions. A 3 kVA transformer-based hardware prototype is constructed, incorporating a Push-Pull converter for harmonic power recovery and battery charging. Experimental results, including waveforms, power analyzer data, and insights into converter design, validate the system’s functionality. Key metrics such as Total Harmonic Distortion (THD), power factor, drainage power recovery, and efficiency are also examined. This work demonstrates a cost-effective and technically viable solution for improving power quality and optimizing EV charging at BSS.