Incorporating Charger Efficiency into Electric Vehicle Charging Optimization

Optimization of electric vehicle (EV) charging will allow network operators to improve power quality and avoid costly reinforcements. Existing problem formulations allow EV charging power to vary continuously in order to achieve convexity and a tractable solution. However, at low powers EV chargers become inefficient and this inefficiency is not taken into account in these formulations. Here, we use real charger efficiency data to demonstrate how including this relationship alters the optimal action. For managing network power flows, we are often only concerned with the network behaviour at lower time resolutions. In this case, we suggest a heuristic method of altering the results of convex optimizations such that low charging efficiency is avoided without altering the behaviour at lower resolution.