R&D of non-contact rapid charging inductive power supply system for electric-driven vehicles

Our research group has developed a non-contact rapid charging inductive power supply (IPS) system with safe, simple, and rapid recharging characteristics for electric-driven vehicles principally for electric vehicles and plug-in hybrids. Outstanding features of the system include high efficiency, significant weight reduction, and a long air gap, and have been implemented through the optimisation of the shape of the track and pickup. This paper mainly focuses on the results of performance evaluation tests of the developed system. The results obtained are listed below, a) Through non-contact electric power transmission experiments, the attainment of a 92% total efficiency was confirmed during 30 kW transmissions, b) The developed IPS was installed on an electric micro-bus WEB-1 Advanced. Non-contact power transmission was conducted, and the successful recharging of the on-board battery was confirmed, c) The weight of batteries mounted can be reduced by implementing the IPS on electric vehicles with frequent recharging. Under the operating conditions studied in our project, it was concluded that an approximately 9% reduction in electric consumption rate can be achieved through 11% reduction in vehicle weight, d) Taking advantage of the increased flexibility in weight resulting from implementation of the IPS, a narrower SOC operating range can easily be achieved for the purpose of prolonging battery life. Under the operating conditions studied in our project, it was concluded that an approximately 55% reduction in SOC range can be achieved.