Prediction of Electromagnetic Radiated Emissions in 14/42V Vehicle Electrical Systems by Method of Moments

In this paper the method of moments (MoM) is used to predict the electromagnetic radiated emissions from typical vehicle electrical loads used in dual voltage automotive distributed architectures. In particular the studied load is a fuel pump drive supplied at 42V power net, composed of a 14 V DC electrical motor and a DC/DC step-down converter. The evaluation of electromagnetic emissions is based on current measurements and on the numerical solution of a modified version of the electric field integral equation (EFIE) in frequency domain. Time profiles of electromagnetic interesting quantities are computed by using a discrete Fourier transform algorithm. The proposed approach allows to consider the electromagnetic compatibility (EMC) since the design stage, together with performance and cost aspects, in order to obtain reliable systems. The developed radiation model permits the prediction of radiated disturbance and also the identification of EMC oriented design and optimisation criteria. Moreover, the presented model can be used to define, for the new vehicle electrical architectures, low cost EMC test methods and appropriate technical standard requirements.