Evaluation of Radiated EMI in 42 V Vehicle Electrical Systems by FDTD Simulation

In this paper a full 3D numerical scheme, based on the finite difference time domain method, is used to predict the electromagnetic radiated interference generated by 42 V vehicle power electronic driven electrical loads. An experimental set-up has been arranged on purpose in order to validate the proposed simulation tool. To this aim, the features of a semi-anechoic electromagnetic chamber have been exploited in order to operate in a shielded test site for the measurement of near field radiated emissions. Two different three-dimensional geometrical configurations of realistic vehicle installations of the loads, are studied. A comparative analysis among measured and computed results is performed. A good agreement between simulated and measured data is obtained. The proposed approach is suitable for the prediction of radiated electromagnetic interference generated by DC/DC converters, and particularly, by dual voltage vehicle electric plants. In fact, due to the presence of complicated layout, the prediction of the electromagnetic emissions can be an useful task in order to evaluate the electromagnetic compatibility compliance since the design stage. Furthermore, with the growing market penetration of the “More Electric Vehicle” concept, in designing new vehicle electrical architectures, low cost test methods for electromagnetic compatibility assessments and suitable technical standard requirements have to be introduced. The proposed simulation tool can be usefully adopted to this aim. As an important advantage, it requires only a current measurement in time domain. Such measurement does not need the use of a special test site or of a radiated field measurement set-up.