Relating Electric Vehicle Charging to Speed Scaling with Job-Specific Speed Limits

With the adoption of electric vehicles emerges a need for coordinated charging strategies to cater to the increased and often synchronized energy demand without violating physical infrastructure limits. Common charging strategies repeatedly solve a corresponding offline problem. In “Relating Electric Vehicle Charging to Speed Scaling with Job-Specific Speed Limits,” Winschermann, Antoniadis, Gerards, Hoogsteen, and Hurink thoroughly analyze that offline problem and present the flow-based offline charging scheduler (FOCS), an algorithm that solves the problem to optimality. The authors continue to quantify the approximation ratio of repeatedly solving the offline problem throughout the day as opposed to solving the offline problem with a priori knowledge of future arrivals. Numerical experiments confirmed that the found worst-case approximation ratio of 4 is far from the achieved empirical ratio of 1.3 when evaluating the ratio for real-world electric vehicle charging instances. Experiments based on that same real-world data show that FOCS only takes seconds to schedule 400 EVs in 15-minute granularity, which is competitive with commercial solvers.