Published on June 2nd, 2016 | by James Ayre1
Toshiba Begins Field Testing Contactless EV Charger For Buses
Field-testing of a new contactless, electric vehicle fast charging system developed by Toshiba Corporation has just begun.
The field-testing process will be based around a medium-sized electric bus, and will run from June 1st until December. The 45-seat electric bus (EV bus) being used during the trial features a 52.9 kilowatt-hour (kWh) SCiB battery-pack, which is also in its development stage.
Field testing will include regular 6.8 mile (11 kilometer) trips between All Nippon Airways Company facilities in Tonomachi, Kawasaki, and Haneda Airport in Tokyo. Travel elsewhere may constitute part of the field-testing period as well.
Toshiba provides more:
The contactless charger, designed in collaboration with Professor Yushi Kamiya of the Faculty of Science and Engineering at Waseda University, replaces conventional electromagnetic induction1 with an innovative and highly promising magnetic resonance2 system that is installed in the ground, under the bus. The system is easy to operate; charging starts once the driver pushes a button on the bus dashboard. As it is cable-free, all risk of electric shock is eliminated.
Electromagnetic induction requires close alignment with the battery, and a small distance separating charge transmitting pad and receiving pad. Magnetic resonance is much more forgiving: The charge pad of Toshiba’s system and the SCiB™ battery can be misaligned by as much 20cm along the width and 10cm along the length, and they can be as far as 10cm apart. Tests have verified that the system’s radio emission level meets limit regulations and do not interfere with radio signals of nearby equipment.
The SCiB™ battery of the type installed in the test EV bus is rugged, reliable and has a long life, showing almost no fall-off in performance even after 15,000 quick charge and discharge cycles. It is highly suited for use on shuttle buses operating at locations such as tourist sites and airports, which must combine heavy use with frequent and fast charging. It takes only 15 minutes or so to charge SCiB™ to a level necessary for the EV bus to run one-way between the test sites.
A related field-testing program deploying similar charging technologies was also begun by partners back in February, and is slated to run until at least December. We’ll keep you posted as the findings of these programs begin coming in.
Contactless charging where power is transferred by magnetic fields using magnetic inductive coupling between coils of wire.
Magnetic resonance has a longer power transmission range than electromagnetic induction, realized by utilizing magnetic resonance to equalizing the resonance frequency of the transmitting pad and receiving pad in addition to power transmission by electromagnetic induction.