Abstract
Bombardier’s groundbreaking PRIMOVE® technology provides wireless, contactless power transfer for all types of electric and hybrid vehicles including trams, buses, and cars. This unique system allows electric vehicles to be wirelessly recharged either in motion (dynamic charging) or at rest (static charging) minimize impact on driving habits or journey times. Based on automatic inductive power transfer, PRIMOVE® frees e-mobility from the constraints of cables, wires and plugs - making electric transport flexible and convenient [1]. By increasing charging power (3.6 kW, 7.2 kW and 22 kW available for car, up to 200 kW for bus and tram), the charging time is decreased significantly. In addition the inductive transfer solution can be integrated into the road and roadside with the result that visual pollution is minimized.
During the charging process, the electromagnetic field (EMF) level in public area requires to be limited below the levels defined in ICNIRP Guidelines (6.25 uT in frequency range 3 kHz to 150 kHz) [2][3]. The public areas include the space inside the vehicle and the free space beside vehicle giving protection to passengers, driver and pedestrians. In addition to the above human exposure requirement, the EMF level inside the vehicle are controlled to ensure electromagnetic compatibility of the electronics installed in vehicle.
This paper describes the process of how the above requirements were achieved. In particular the paper will address the use of methodology of electromagnetic simulation, supported by well-designed research and verification testing. The impacts of the stray magnetic field and design objects of the vehicle screening are analyzed firstly. Afterwards the screening methods applied on the vehicle chassis and on-board alternating current (AC) cables are analyzed and compared in detail, including installation position of the screening metal sheet, screening material selection and weight optimization. Finally the paper will present the results from the latest projects demonstrating that the 6.25 uT limit in all public areas is achievable with 200 kW inductive power transfer. The paper will go on to describe the relationship with the independent assessment body TUV SÜD who assess all PRIMOVE® electromagnetic compatibility (EMC) and EMF activities.
KEYWORDS – wireless charging system, electromagnetic field control, screening technique, electric vehicle, ICNIRP guidelines