On-line electric vehicle system optimization for application to public transportation

Abstract

On-Line Electric Vehicle (OLEV) is an innovative electric transportation system developed by Korea advanced Institute of Science and Technology (KAIST), which can pick up electricity wirelessly from power tracks installed underground. Contrary to plug-in electric vehicles (PEVs), OLEV can be charged during driving status if it pass by a power track and it uses electric power from battery only when it is moving on the road where power tracks are not installed. Therefore, OLEV receives a lot of attention as an alternative of existing electric vehicles. OLEV system is mainly comprised of vehicles and power tracks. This system is more suitable for public transportation such as bus which circulates identical route every day than individual cars. For commercialization, the thing which should be considered most importantly is to minimize initial investment cost. Also we should consider that there are several tangled routes and it is difficult to establish OLEV systems of the routes at once if limited budget and some traffic conditions are not satisfied. Therefore, in this study, the main objective is to propose an optimization based system for determining the allocation of charging infrastructure of OLEV and the battery capacity considering multiple-route public transportation system. Mathematical models for single-period and multiple-period optimization model are suggested, and example problems are solved by genetic algorithm (GA) which is one of the most famous metaheuristics. In addition, the performance of GA is verified by comparing with the solutions of Cplex solver in small scale problems, and then GA solves a large scale problem which reflects real bus routes in Gumi city. Furthermore, an OLEV system design tool is suggested by the integration of the optimization tool and geographic information system.