Study on shielding effectiveness of electronic enclosures with connected accessories under corrosive environment for automobile industry

The automotive industry is gearing for a drastic shift towards the electric vehicles and also leaping for the autonomous vehicles. This simply means that more and more electric/-electronic systems will be making their way inside the vehicles. Apart from the functional and safety requirements, compliance with EMI/EMC tests and measurement is the most important step in introducing a new product to market. In the automobile sector, the electronic parts or subassemblies are required to meet the EMI/EMC requirement as specified by the manufacturer or the competent authorities. Such components can include various sub-systems or wiring harness connected via detachable connectors which depend on physical contacts for the electrical connectivity. Once a design is finalized, the product is subjected to different EMI/EMC tests. These tests ensure that the components perform normally in an electromagnetic environment. It has to be noted that in almost all the cases, the tests are carried on products with fresh components. However in the real life condition, the subassembly component characteristics, especially at the interconnects changes due to corrosion, aging, strained harnesses, discontinuities induced due to vibration etc. These changes introduce additional parasitic circuits in the system. The physical discontinuities can even cause make and break of the circuit leading to electromagnetic emissions. The impact of such changes on the EMI/EMC compliance is often ignored. In this paper, an attempt is made to model such changes and to demonstrate the effect on the radiated emission patterns. The study is carried out using 3D electromagnetic modeling and simulation tool.