Evaluation Of Magnetic Field Emissions In Automotive Electrical Drives

An automotive electrical drive system involves high currents for its operation. These currents result in high level magnetic field emissions which face stringent requirements. The use of a shielded system and proper grounding methods permit to eliminate most of the electric field emissions. The magnetic field emissions are functions of the effectiveness of the used shielding, geometrical arrangements and the resulting current distributions in the system.This contribution provides a methodology to estimate emitted magnetic fields only from inner conductor currents. In the first step, the currents distributed in the cable shields and ground system are calculated from physical and geometrical parameters. In the second step, transfer functions for current loops are established to consider the influence of the geometry of the system.