Safety Standard Compliance of Human Exposure From Vehicle Cables Using Coupling Factors in the Frequency Range of 0.3–400 kHz

Human safety from electromagnetic fields in the cabin of automotive vehicles has become an important issue with the increased use of powertrain electrification. A current passing through the cable above the floor is one of the dominant sources emitting magnetic fields. However, the presently used method of assessing the compliance of the measured magnetic field with the permissible magnetic field (called reference level in International Commission on Non-Ionizing Radiation Protection guidelines) is overly conservative because the reference level is derived assuming a uniform field distribution. In such cases, internal electric fields should be evaluated for proper compliance. However, it is unclear how to best approach this in a practical situation. In this study, frequency- and body-part-dependent coupling factors corresponding to the guidelines for the general public are proposed for the assessment of internal electric field induced by nonuniform magnetic fields from the cable. The measured spatial peak magnetic field strength should be multiplied by the coupling factor before comparison with the field reference levels. In the simulated exposure scenario, the computational results indicate that the basic restrictions provide a safety margin of 11 over the field reference levels. The coupling factors may prove useful as a new straightforward compliance assessment measure in vehicle cabins.