High-voltage wire shielding layer of electric vehicle cable
The shielding is to ensure the transmission performance of the system in the environment with electromagnetic interference. The anti-interference performance here should include two aspects, namely the ability to resist external electromagnetic interference and the ability of the system itself to radiate electromagnetic interference.
A shielded cable is a cable with one or more (insulated) wires wrapped by a common conductive layer. This common conductive layer is the shielding layer of the cable. It is generally composed of braided strands of copper (or other metals, such as aluminum), non-woven spirally wound copper wires or a conductive polymer layer. The braid is generally red copper or tinned copper. The wire and cable industry is China's second-largest industry after the automotive industry, with product variety satisfaction and a domestic market share exceeding 90%.
Braided mesh shields do not provide 100% coverage, because they always have small gaps on the surface of the conductor. Depending on the tightness of the weave, the woven mesh can usually provide 70% ~ 95% coverage. Although the metal foil has a higher shielding coverage, this does not mean that its shielding effect is better. The reason is that copper has a stronger conductivity than aluminum, which allows the woven mesh to conduct electromagnetic noise better. Therefore, as a shielding layer, the woven mesh often has a better shielding effect.