Simulation of Low-Frequency Magnetic Fields in Automotive EMC Problems

This paper presents a computationally efficient method for solving automotive low-frequency electromagnetic compatibility (EMC) problems by using integral equations. We consider the interaction of magnetic fields with thin, finite, conducting 3-D metallic structures, obtaining the fields radiated by these structures by using single-and double-layer equivalent currents. Our proposed numerical solution is unique in its representation of equivalent currents as the sum of solenoidal and nonsolenoidal components found using the method of moments (MoM) in two steps: first, the solenoidal currents are found using loop basis functions, after which the nonsolenoidal currents are found. Decomposing the equivalent currents into solenoidal and nonsolenoidal components provides a total solution that is computationally efficient for problems dominated by magnetic fields. We validated this numerical electromagnetic solution against semianalytical solutions and measured data and illustrated its applicability by analyzing three practical automotive problems. We then analyzed the magnetic fields generated by a power cable inside a car, suggested a methodology for optimizing the locations of antennas for smart-entry systems, and studied the EMC implications of an inductive-charging system in an electric vehicle.