Wireless power transmission for a traveling mobility scooter

A wireless power transmitting system for a traveling mobility scooter based on magnetic resonance has been developed. In this paper, an overview of the system will be presented. Large square coils are set up on the road surface where a mobility scooter with a small coil and no battery is traveling. The power source is a Class E amplifier operating at 13.56MHz with an output power of 150W. Power is selectively supplied to the coil upon which the vehicle is passing at the moment; vehicle position is detected by ultrasonic sensors. A system to automatically control the transmitting output power was developed, because it is necessary to supply a constant voltage to the scooter. The overall power efficiency when the power receiving coil is inside the area delimited by the transmitting coil is 47%.