Hierarchical Control of Megawatt-Scale Charging Stations for Electric Trucks With Distributed Energy Resources
Ahmed A. S. Mohamed, Myungsoo Jun, Rasel Mahmud, Partha Mishra, Serena N. Patel, Isaac Tolbert, Shriram Santhanagopalan, Andrew Meintz
Abstract
Electrifying medium- and heavy-duty trucks is critical to decarbonizing the transportation sector. The energy needs of electric trucks will likely require megawatt-scale charging stations, which could significantly stress the electric distribution grid. Distributed energy resources (DERs) can alleviate this stress and reduce charging costs with proper management. To that end, this work develops a hierarchical predictive control algorithm for future multiport megawatt-scale charging stations that can provide real-time energy management for stations, decide charging rates, dispatch energy storage system (ESS), and provide grid voltage support. We integrate three algorithmic components: 1) an energy management optimization (EMO) that provides supervisory control to DER assets and charging loads at a minute scale; 2) a real-time energy management system (RT-EMS) that heuristically compensates for fast disturbances at a subsecond scale; and 3) a model predictive control (MPC)-based battery management system (BMS) that communicates future charging demands to the EMO to manage the overall megawatt-scale site. Validation in a controller hardware-in-the-loop (CHIL) environment shows that the hierarchical controller can reduce the total energy consumption from the grid by approximately 28% compared to an uncontrolled case for the station configuration in this article without impacting charging time.