Dubai’s Roads and Transport Authority (RTA) has launched the test-run of dynamic wireless charging of electric vehicles and buses in motion using the shaped magnetic field in resonance (SMFIR) technology developed by the Korea Advanced Institute of Science and Technology (KAIST).
The contactless charging SMFIR technology enables safe transfer of a large amount of energy from a power grid under the road to electric vehicles at rest or in motion, thus removing the need for the vehicles to stop at charging stations.
The RTA is undertaking this project, which is part of Dubai Future Accelerators, in collaboration with Dubai Electricity and Water Authority and Dubai Silicon Oasis. The initial phase covers building the infrastructure and laying an embedded power-charging grid underneath a 60-metre road strip at the Dubai Silicon Oasis.
The wireless charging technology is provided by South-Korea-based WiPowerOne (Wireless Power 1), a spin-off company of KAIST that specialises in manufacturing wireless charging infrastructure for on-line electric vehicles/open leading electric vehicles (OLEVs).
OLEV technology consists of inverters that convert 3-phase 380V power to 20kHz 200A, power supply lines installed under the road, pick-up device that converts magnetic fields to electric energy, motors that drive vehicles, and a battery that stores energy. When electric power is applied to the power supply line installed under the road, the magnetic field generated from the power supply line is sent using the SMFIR technology to the pick-up device attached to the lower part of the vehicle using 20kHz frequency. The pick-up device converts the magnetic field to electrical energy, which drives the motors. The remaining energy is used to charge the battery. In areas with no power supply line, the OLEV bus uses the electric energy stored in the battery.
Since 2013, KAIST has been testing its OLEV technology for electric buses at the KAIST campus and in the city of Gumi in South Korea. According to the inventors at KAIST, the SMFIR technology provides a solution to the barriers to commercialization of electric vehicles such as the high costs of charging infrastructure and batteries, vehicle weight and driving distance. The power supply infrastructure for OLEVs costs less because it requires only 5–15% of the entire service route including start and end points, bus stops, crossroads and parking areas.
Mattar Mohammed Al Tayer, director-general and chairman of the board of executive directors of RTA, said: “The RTA has tested an electric vehicle and a bus on this path, and results proved a highly efficient wireless charging system comparable with the cable charging. Moreover, the electromagnetic level on board was within the accepted global range. The successful operation of electric vehicles using this technology and their deployment in RTA’s public transport fleet hinges largely on the availability and reliability of the charging technology. It enables seamless operation of the vehicle without any stopping at charging stations. Embedded under the road, the charging system is invisible and as such has no visual pollution impact on the city. Also, it does not hamper the movement of people and vehicles like on-road cable chargers.”