Electric vehicle (EV) is becoming popular in near future to replace internal combustion engine vehicle (ICV) because EV is a solution for environment issues and fossil fuel exhausts caused by ICV. However, the main drawbacks of conventional EVs include short driving range per charge, heavy on-board battery, inconvenience for users, and sparking effects due to charging of EV via plug-in connector, etc. With developments of wireless power transfer (WPT) technology, all of these drawbacks can be overcome. EV will be conveniently charged without any mechanical contact, so there are no sparking effects. By installing WPT system on the road, EV can be powered from the road. Therefore, the concept of driving range per charge seems non-existent, and only a small on-board battery is required as a supporter.
In order to put WPT technology for EV into practical use, infrastructure of WPT system plays an important role to reduce its system cost and guarantee the smooth operation of EV as desired. It can be seen that if WPT system is equipped the road entirely, the construction cost is unacceptably expensive and not really necessary in particular cases. Therefore, for minimizing the total length of WPT system installed on the road, strategy to allocate the WPT system is non-trivial. In this work, the author presents a new approach for allocating WPT system from viewpoint of an optimal control problem, where the global optimality of solution is guaranteed.
Furthermore, in the conventional approach for allocation of WPT system, information of EV operation such as EV speed profile and power demand is required. In this work, the author also proposes a new methodology based on mathematical optimization method for simultaneously designing EV speed profile and allocation of WPT system in a lane segment, with the aim to reduce the cost of WPT system by minimizing its length. By parameterizing both EV operation and allocation of WPT system as unknown parameters, a nonlinear optimization problem with involved constraints of EV operation and battery sustainability is established for optimizing these unknown parameters to minimize the length of WPT system. Therefore, optimal speed profile of EV and optimal allocation of WPT system can be simultaneously determined. The proposed approach is applied in a scenario of autonomous driving EVs, where they will accurately follow the designed speed profile. We show that our proposed method gives a better solution than the conventional method in term of reducing the length of WPT system under the same operational constraints of EV and battery.