RCCN WeChat QrCode
Mobile WebSiteThe role of the high-voltage wiring harness of the car is to connect various high-voltage electric devices and play a role in transmitting high-voltage power. From the figure below we can clearly see the connection of the various components in the high voltage system. All the arrow lines between each part are high voltage lines. High-voltage harnesses include fast-charged high-voltage lines, slow-charged high-voltage lines, high-voltage cables that battery packs connect to PDUs, and high-voltage cables that connect PDUs to MCUs. Affected by the layout of the entire vehicle, these high-voltage harnesses are the focus of our attention. Other high-voltage lines are sometimes brought by the components.
High voltage
The voltage of the battery pack is a high voltage of 100~400V. This imposes better requirements on the insulation of the high-voltage wiring harness and must be well insulated. "GB T 18384.3-2015 Safety Requirements for Electric Vehicles - Part 3: Personnel Protection Against Electric Shock" Under the maximum working voltage, the insulation resistance of the DC circuit should be greater than 100Ω/V, and the AC circuit should be greater than 500Ω/V.
After years of development, the technology of high-voltage wire harnesses is relatively mature, but insulation resistance should be the focus of our design.
2. High current
In high-voltage systems, high-voltage currents can reach several hundred amps instantaneously, which imposes higher requirements on the current carrying capacity of high-voltage wire harnesses. When considering the design of high-voltage wiring harness, consider it fully.
3. Protection level
Because the erosion of water and dust can easily cause the insulation performance of the wire harness to drop, resulting in potential safety hazards such as high-voltage breakdown and leakage. Special attention must be paid to the arrangement of high-voltage wire harnesses to avoid placing them in places with accumulated water. If they are arranged under the floor, they should be Add appropriate shields. But even so, the design of the high-voltage harness protection rating should be the highest to meet the national standard IP67 standards.
. Anti-electromagnetic interference
The electromagnetic environment of high-voltage systems is more severe. On electric vehicles, repeated changes in the electrical load and the frequency conversion technology used in the system cause severe fluctuations in the voltage, current, and frequency of the wiring harness, resulting in large electromagnetic interference. At the same time, the high-voltage wiring harness It will also affect the surrounding electrical and electronic equipment, so the wiring harness needs to shield electromagnetic interference to meet the requirements of electromagnetic compatibility.
5. Cost
High-voltage wire harnesses are more expensive than ordinary low-voltage wire harnesses. Therefore, in wire harness design, over-design of wire harnesses should be avoided as much as possible.
