Koreans Debut EV Bus-Wireless Roadway

Korea Advanced Institute of Science and Technology's New OLEV (online electric vehicle)

Koreans Debut Electric Bus Line Powered By Wireless Roadway

KAIST (Korea Advanced Institute of Science and Technology) has replaced a ICE (Internal Combustion Engine) train that runs inside Seoul Grand Park in Gwacheon City with an online electric vehicle (OLEV).  The EV bus gets power from cables that are buried underground through a non-contact magnetic charging method, called electromagnetic induction. The OLEV receives electricity when it passes over the cables and that power can be used to operate the vehicle or charge the batteries.  This electric vehicle proves that there is no need to create charging stations, schedule time for recharging batteries or even equipping EVs with large banks of batteries.  This particular OLEV only has about 1/5th of the batteries typically installed in electric vehicles.  It is estimated that a city could have a viable environmentally friendly all electric public transportation system by strategically installing the underground power cables at particular: curbs, bus stops, parking lots, and intersections along approximately 20% of any bus route to power one of these electric buses.

This technology solves many of the battery issues that relate to EVs such as: expense, charging time, maintenance and general size and quantity requirements.  This non-contact method of powering EVs is safer because it eliminates electric shock hazards that are possible with overhead wire streetcar and tram systems.

The recharge strips are several meters in length and feature a sensor that basically operate as an on/off switch for the power transfer for a properly equipped EV bus or car.

KAIST's Wireless EV Roadway

KAIST’s OLEV research team has previously demonstrated that their system can have a 70% efficiency level of power transmission with a air-gap of 12 cm (and up to 17 cm).  The KAIST system proves the viability of electric vehicles for commercial use by making major advances in terms of capacity and efficiency of wireless powered roadway systems.  They have also been able to get the electromagnetic field (EMF) of their system well below the international standard of 62.5mG.

The particular OLEV (one engine and three passenger cars) at the Seoul Grand Park has a electric pick-up capacity of 62kw/h using an air-gap height of 13 cm from a road to the bottom of the vehicle, which translates to a 74% energy transfer efficiency. The system is functioning well with underground power supply cables only covering 16% of the total route.