From the perspective of the three elements of electromagnetic interference, the main function of shielding is to cut off the propagation path of electromagnetic noise. The battery pack casing can be regarded as shielding the electromagnetic interference conducted on its internal and external wiring harnesses, but because the battery pack casing has power lines in and out, the battery pack casing is an incomplete shield. In the field of electromagnetics, shielding can be divided into electrical shielding, magnetic shielding and electromagnetic shielding. Therefore, this paper studies its influence on the electromagnetic radiation emission of the whole vehicle from the perspective of shielding mechanism.
Due to the role of the switch components in the power battery system, strong current fluctuation di/dt and voltage fluctuation dv/dt will be generated on the power cable, and these interferences will have an important impact on the radiation emission of the vehicle. This paper analyzes the mechanism of electromagnetic shielding, and uses the three-dimensional electromagnetic field simulation software CST to establish a vehicle radiation model. Based on the electromagnetic shielding mechanism, different materials, thicknesses, and structures of battery pack shells and internal wiring harnesses are incorporated into the vehicle electromagnetic radiation emission model. In the simulation study, the influence of the shielding of different battery pack shells on the radiation emission of the whole vehicle is studied, and the simulation results have a good reference significance for suppressing the radiation emission of the whole vehicle.