Evaluating low frequency magnetic field exposure from traction current transients in electric vehicles

Measurements of low frequency magnetic field in a range of vehicles with electric powertrain indicate that the highest field levels are found close to power cables routed near the feet of the occupants. However, the interpretation of these broadband, non-sinusoidal fields in terms of human exposure recommendations is not straightforward as additive effects must be taken into account. This requires a time-varying, broad-band field exposure metric to be reconstructed via an inverse Fourier transform. A similar approach has also been applied in 3D field simulation models based on measured cable current waveforms. Such models can be used to investigate spatial field distributions, as well as the effects of vehicle material properties, structural features, and the likely impact of exposure mitigation strategies.