Modelling and Integration Analysis of High-Power Charging Stations Equipped with a MWh Scale Battery Bank

The rapid adoption of electric vehicles (EVs) has led to a growing demand for fast-charging infrastructure. Such infrastructure in turn poses significant challenges to existing power grids due to high instantaneous power demands. Battery banks can be used as a buffer in a charging station to mitigate the pressure on the grid. This paper develops a method to model and analyze high-power charging stations equipped with a battery bank as energy storage, aiming to support grid stability and maximize economic benefits. Specifically, the study answers (i) how to effectively integrate a high-power battery bank into a high-power charging station, and (ii) how key parameters influence the integration from both operation and economy points of view. Modelled and simulated in MATLAB/Simulink, the proposed approach calculates and analyzes power flow among the grid, the battery bank, and EV batteries, relying on real-time load profiles and battery state-of-charge thresholds. Simulation results show that 1) storing low-cost off-peak energy and 2) discharging of the battery bank during peak grid load periods significantly reduce grid dependency and increase operational profits for the charging station. A parameter-based analysis illustrates that larger battery bank capacities, wider state-of-charge ranges, and narrower grid-load-variation bands benefit both the charging station owner and grid operator.