P-HIL Model Development for MW Charging Sites Incorporating Real-World XFC Load Profiles

This paper develops a P-HIL model to analyze the real-world impact of XFC charging profiles on the grid frequency. Using charging profiles captured for different EVs and E-trucks at different start SoC and temperature conditions, a database of 93 profiles was used to develop a MW-level charging site scenario. The scenario envisions a charging site with EVSE usage that is mixed for fleet charging at a small business with public charging availability when fleet charging is undesired. A statistical study of 1446 DCFC and XFC charging sessions was conducted to identify start and end SoCs and develop the expected load profiles. Two real-world XFCs and BESS have been connected to a real-time digitally simulated modified IEEE 37-bus distribution grid and run on an Opal-RT real-time digital simulator. Several communication protocols, including UDP, Modbus, OCPP, and TCP have been employed in the associated MQTT IoT environment. This model can be used to design the optimal control strategy that could determine the amount of injected or absorbed active power from the co-located BESS to mitigate the effect of running a large number of XFCs clusters on the grid frequency and rate of change of frequency.