Utilizing Energy Storage System for Three-Level Voltage Balancing Mechanism in Electric Vehicle Fast Charging Station

The growing demand for electric vehicles necessitates the expansion of charging infrastructure. This paper introduces a three-level voltage Fast Charging Station architecture using a Neutral-Point-Clamped Converter, offering higher power and efficiency compared to traditional converters. However, the Converter faces voltage imbalances due to neutral-point potential drift, potentially damaging the converter. To address this, this paper employ Voltage-Oriented Control and Space Vector Modulation for power redistribution. Nonetheless, the modulation stage alone cannot handle extreme uneven load. Therefore, the paper also proposes a balancing mechanism that uses any existing energy storage system to act as a load to drain the minimum amount of current from the less congested bus to maintain the power ratio between the upper and lower bus. This method eliminates any additional balancing circuit and thus reduces the fast-charging station equipment and cost.