Optimization of Charging Stations for Electric Vehicles on Motorways

Abstract

The electrification of transport is considered to be a promising way for reducing negative environmental impacts. It has a high priority for many European nations but its dispersion is far behind expectations. One cause for this lag is the insufficient charging infrastructure. When charging infrastructure is established, the question arises where to place new charging stations and/or how to extend existing ones. We present the results of a study commissioned by the Asfinag (Austrian motorway operator) which addresses this question. Further we propose a method for an optimized siting and sizing of fast charging stations. The objective is to establish a fast charging infrastructure for battery electric vehicles on motorways to enable long distance trips beyond cruising ranges.
Charging demand is estimated based on traffic flows between origins and destinations. Predicted penetration rates for battery electric vehicles for the years 2020 and 2025 are used to estimate a traffic demand, described by path flows, for battery electric vehicles. Path flows beyond maximum cruising range are selected, and a sub-route is determined, bounded by the first possible and latest necessary location for charging.
Finally, a facility location problem is formulated in order make trips beyond maximum cruising range on motorways in Austria feasible. In the optimization problem, only rest areas are considered as possible locations for charging stations. Existing charging stations on motorways are included. In addition to determining locations, the number of CPs per charging station to be build is investigated.