A Comparison of AC and DC Distribution Architectures for Electric Vehicle High Power Charging Facilities

Despite the many known benefits of DC distribution, the majority of electric vehicle (EV) high power charging (HPC) equipment are designed for AC distribution. This is primarily due to the historical momentum of grid technologies and equipment maturity. This paper provides a relative comparison for EV charging hubs to quantify the benefits of a DC architecture compared to an AC one. NREL's EVI-EnSite: Electric Vehicle Infrastructure - Energy Estimation and Site Optimization Tool is used for the analysis. The benefits of a DC distribution architecture scale with the hub size and utilization, where simulations suggest energy loss reduction can exceed 6% for a hub with a capacity of more than five EVs compared to AC. AC/DC converter module investments are 50% of what is required for AC distribution for a hub with a capacity greater than 10 EVs, while distribution cable investments for DC are 40% of what is required for AC regardless of hub size.