Evaluating the Impact of AC-DC Converters in Extreme Fast Charging (XFC) Stations on Grid Quality

With the increasing demand for electric vehicles (EVs), improving EV specifications is essential. Extreme Fast Charging (XFC) systems can improve the EV user experience by reducing the time spent charging a car's battery. These systems require chargers with high-power capacity. This work presents an assessment of the impact of XFC on the utility grid. Two AC-DC converters that interface XFC with the grid are studied by simulating the charger setups in PSIM®. Vienna three-phase rectifier and three-phase PWM converters were selected for their ability to regulate output voltage and power factor correction functionality. The impact of the two AC-DC converters on the THD and power factor is thoroughly investigated. Although the performance of the two converters is comparative, the result revealed that Vienna offers a wider power operation range without violating the THD limit compared to a three-phase PWM rectifier. The registered THD in the case of the Vienna rectifier is below the 5% threshold if the charger output is above 50% of its rated power. The results suggest that the Vienna rectifier will outperform other topologies in this application.