Development and performance evaluation of an electric mini bus equipped with an inductive charging system

The limited range, high cost and long charging time of electric vehicles continue to stand in the way of their widespread adoption. In response to this, our research group has created the "Waseda Electric mini Bus (WEB)" series of vehicles based on a short range, frequent charging concept that minimises the weight and cost of batteries compared to other electric vehicles. This paper reports on the design, construction and performance evaluation of the new "Waseda advanced Electric mini Bus 3 (WEB-3)", which is larger than previous vehicles and utilises an improved inductive power supply (IPS) for non-contact rapid charging. A diesel bus was converted to an EV, and the engine, flywheel and clutch were removed, reducing the vehicle's rotating weight by 80 %. A new inductive charging system was designed and fabricated, allowing non-contact rapid charging from a transmission coil in the road surface over a longer air gap of 140 mm, at 92 % efficiency.The finished WEB-3 was tested on public roads in Honjo and Kumagaya cities, Saitama prefecture, Japan. An effective reduction in CO₂ emissions of 60 % over the original diesel bus was achieved.