Requirements for cable insulation of new energy vehicles

China [CN]

In the automotive industry, the design service life of cables at the specified temperature class is 3000 h. In recognized cable standards (such as GB/T 25085, GB/T 25087, QC/T 1037 and ISO 19642), this value is usually used for long-term aging test. The special requirements of customers in high-voltage applications may exceed 3000 h, and the cumulative operation time at the specified temperature may even reach 12000 h. The heat resistance of insulating materials is proportional to the service life. The more heat-resistant the cable is, the longer the service life can be carried.

In many cases, the challenge for the development of electric vehicles is to incorporate more electrical components into the space. Cable and connector routing also requires space. A bending radius that usually leads to tension. Due to the inherent design of conventional cables, high bending forces are difficult to overcome. In order to solve this problem, high flexibility of high-voltage cables is essential. Only a flexible design can make routing through vehicles easy. If the motor is located near the moving part of the vehicle and then causes continuous vibration of the connected high-voltage cable, it is required to be designed to withstand high cyclic bending to ensure good bending resistance.

At present, the insulation materials of high-voltage cables are mainly cross-linked polyolefin and silicone rubber. Crosslinked polyolefins can resist heat up to Grade D, and have high mechanical strength and resistance to liquid chemicals. The outer diameter can be designed more precisely. For Grade D cross-linked polyolefin, halogen-free is usually not available, while silicone rubber has excellent heat resistance and flexibility. It is environment-friendly and halogen-free, and is the preferred material for designing higher heat resistance grade E high-voltage cables.

Conclusion: In contrast, the rated temperature of cables used by current vehicles is usually 105 ℃, as long as the cables are not used in the engine compartment or other areas with high temperature resistance. High voltage cables of electric vehicles are usually higher than this temperature, such as Class C (125 ℃) or Class D (150 ℃). If the route of the electric vehicle is unfavorable, such as near the exhaust pipe, in front of the motor, on the back of the battery, the OEMs will even put forward higher requirements for high temperature resistance. For example, Class E (175) ℃. The higher heat resistance of insulating material determines that the cable can carry higher rated current carrying capacity.

For more information about the electric vehicle product range, you can obtain it in the high-voltage cable leaflet: https://www.omgevcable.com