Shaped Magnetic Field in Resonance Technology and Its Application to Transportation System

KAIST has developed the Shaped Magnetic Field in Resonance (SMFIR) technology that transfers a large amount of energy to electric vehicles when they are running or stationary. The wireless charging SMFIR technology provides a solution to the commercialization barriers of electric vehicles such as the problems of batteries and charging infrastructure.

Using 20-kHz wireless power transfer system based on the SMFIR technology, our eco-friendly On Line Electric Vehicle (OLEV) bus was wirelessly powered by 100 kW through a power grid embedded under the road. On the other hand, using high-capacity, high-efficiency and low-cost 60kHz power supply and pickup systems based on the SMFIR technology, tram and high speed train were wirelessly powered by 180 kW and 1 MW through a power grid built in rail roads, respectively.

The commercial OLEV tram has been operated commercially from July 2011 in Seoul National Grand Park. Also, the OLEV shuttle bus has been operated for convenience of students and faculty members at KAIST campus since Oct. 2012. In addition, the world’s first intra-city OLEV bus with 100 KW pickup capacity has been operated commercially at Gumi city from March 2014. Then, airgap is about 20 cm and maximum power transfer efficiency is 85 %.