Clean Transport

Published on August 14th, 2013 | by Cynthia Shahan


Active Wireless Charging In Transit; Remarkable Progress In Korea For Electric Vehicles

August 14th, 2013 by  

Improvements with the electric transit infrastructure unfold at light speed. Active wireless charging in transit with electric vehicles, in this case electric buses, is taking place. Korea has broken through with accelerated wireless power efficiency with the Online Electric Vehicle (OLEV). This technology from the Advanced Institute of Science and Technology (KAIST) is setting another standard that increases the development of electric vehicles and addresses the (slight) time issue of charging. This breakthrough works for personal or public transportation presently, allowing vehicles to be charged while stationary or while moving.

“This is accomplished by solving technological issues that limit the commercialization of electric vehicles such as price, weight, volume, driving distance, and lack of charging infrastructure,” ResearchSEA writes.

Following the development and operation of commercialized OLEV trams (at an amusement park in Seoul) and shuttle buses (at KAIST campus), respectively, the City of Gumi in South Korea, beginning on August 6th, is providing its citizens with OLEV public transportation services.

Two OLEV buses will run an inner city route between Gumi Train Station and In-dong district, for a total of 24 km roundtrip. The bus will receive 20 kHz and 100 kW (136 horsepower) electricity at an 85% maximum power transmission efficiency rate while maintaining a 17cm air gap between the underbody of the vehicle and the road surface.

wireless electric bus

The Online Electric Vehicle (OLEV), developed by the Korea Advanced Institute of Science and Technology (KAIST), is an electric vehicle that can be charged while stationary or driving, thus removing the need to stop at a charging station. (Credit: Image courtesy of ResearchSEA)

This is inspiring progress even to the ones who have unearthed the possibility. As Dong-Ho Cho, a professor of electrical engineering and the director of the Center for Wireless Power Transfer Technology Business Development at KAIST, said: “It’s quite remarkable that we succeeded with the OLEV project so that buses are offering public transportation services to passengers. This is certainly a turning point for OLEV to become more commercialized and widely accepted for mass transportation in our daily living.”

Will we be seeing more of these adaptable accelerated modes of transportation? We will in Korea, at least:

OLEV receives power wirelessly through the application of the “Shaped Magnetic Field in Resonance (SMFIR)” technology. SMFIR is a new technology introduced by KAIST that enables electric vehicles to transfer electricity wirelessly from the road surface while moving. Power comes from the electrical cables buried under the surface of the road, creating magnetic fields. There is a receiving device installed on the underbody of the OLEV that converts these fields into electricity. The length of power strips installed under the road is generally 5%-15% of the entire road, requiring only a few sections of the road to be rebuilt with the embedded cables.

OLEV has a small battery (one-third of the size of the battery equipped with a regular electric car). The vehicle complies with the international electromagnetic fields (EMF) standards of 62.5 mG, within the margin of safety level necessary for human health. The road has a smart function as well, to distinguish OLEV buses from regular cars — the segment technology is employed to control the power supply by switching on the power strip when OLEV buses pass along, but switching it off for other vehicles, thereby preventing EMF exposure and standby power consumption. As of today, the SMFIR technology supplies 60 kHz and 180 kW of power remotely to transport vehicles at a stable, constant rate.

The first two OLEV buses are operational this year. At the end of the year, Gumi City plans to start rolling out more, aiming to have ten on the ground and running by 2015.

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About the Author

is a Mother, an Organic Farmer, Licensed Acupuncturist, Anthropology Studies, and mother of four unconditionally loving spirits, teachers, and environmentally conscious beings who have lit the way for me for decades.

  • José DeSouza

    Wireless “charging” could also be used to power an electric motor
    instead of a regular battery charger. That electric motor would be
    coupled to a hydraulic pump which in turn would be connected to pressure
    cylinders and hydraulic pump-motors in the wheels and… voilà: a
    series hydraulic hybrid electric powered bus. Too many advantages to

    • Bob_Wallace

      Then you’d have to wire every foot of the roadway and the buses would not be able to deviate from that route. They couldn’t drive around the double-parked UPS van.

      • José DeSouza

        An electron is an electron no matter what you do with it, whether it’s used to charge a battery or to make an electric motor turn around. I suppose the above mentioned OLEV bus is recharged by electrical induction at selected sections of its route. By the same token, a series hydraulic hybrid electric powered bus would be able to have its pressurized reservoirs recharged when called for at strategically located induction strips, not necessarily taking up the whole length of the roadway. By doing so, such a bus would also be fully able to drive around any obstacle just as proficiently. Not mentioning “driving around” or even doing right away with the whole issue of propulsion batteries.

        • Bob_Wallace

          If you add in hydraulic storage then it works. But not without storage.

          • José DeSouza


    • ersdrive

      Electric Hydraulic Hybrids are coming, it just takes a long time to get people to understand the advantages

      • Bob_Wallace

        Your website is misleading.

  • Wayne Williamson

    Excellent, although they only state the maximum eff is 85%. I wonder what the actual will be.

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