Internal electric field in pregnant-woman model for wireless power transfer systems in electric vehicles

One of the limiting factors for transmitting power in the wireless power transfer system for electric vehicles is the human safety compliance requirement for magnetic field leakage. Another concern for human safety from electromagnetic fields is the impact on vulnerable populations, such as the foetus and its mother. In this study, the internal electric field in the foetus and mother is investigated in anatomically based pregnant- and non-pregnant-woman models. The effect of different coil designs on the internal electric field is also discussed. The computational results show that the internal electric field strength is smaller in the foetus than in the mother, because the magnetic field there is weaker than around the feet, even though the abdomen of the pregnant woman may come closer to the vehicle than that of a non-pregnant adult female. The allowable transmitting power for safety compliance is of the order of megawatts, which is a magnitude higher than that considered in the standardisation.