With the continuous development of automobile electronic control technology, the number of automobile electronic equipment has increased greatly, the working frequency has gradually increased, and the power has gradually increased, which makes the working environment of the automobile full of electromagnetic waves, resulting in increasingly prominent electromagnetic interference problems. The light may affect the normal operation of electronic equipment, and the heavy may damage the corresponding electrical components.

Therefore, the electromagnetic compatibility performance of automotive electronic equipment is receiving more and more attention, and it is urgent to widely apply the electromagnetic improvement technology of automotive electronic equipment.

Automotive electronic equipment works in a vehicle with constantly changing driving environment. The complexity and variability of electromagnetic energy composition in the environment means that the electromagnetic interference sources to which the system is subject are relatively extensive. The main source of electromagnetic interference in the vehicle is that the vehicle wiring harness is spread all over the vehicle, and it is often subject to electromagnetic interference. So how to deal with itAutomotive wiring harnessThe electromagnetic interference in is particularly important.

Based on many years of experience in automobile wire harness processing, it is necessary to take the following measures:

Shielding interference source equipment and relevant wiring harness: the electronic control unit used by the main electronic control system in the vehicle shall be sealed in the shielded enclosure.

Add a harness filter: for a long harness, in order to reduce the conduction and radiation interference, add a filter on the harness. It is more convenient to connect a suitable ferrite magnetic ring.

Reasonable harness planning: the harness layout should make the low-power sensitive circuit close to the signal source, and the high-power interference circuit close to the load. The low-power circuit and high-power circuit should be separated as far as possible to reduce the inductive interference and radiation interference between the harnesses.

Improved grounding of equipment: good grounding arrangement and improved grounding bonding can reduce high-frequency impedance. The grounding of automotive electronic equipment is mainly connected to the body and the wiring harness shielding layer.

Reduce the area of interference received by the harness: the harness should be designed with minimum length, minimum impedance and minimum loop area. It is better to use twisted pair and other power supply methods with small loop area.

Increase the distance between equipment and interference source: under the condition that the layout of interference equipment remains unchanged, the installation position of sensitive components should be modified to increase the distance to interference source.

In addition, the electromagnetic interference suffered by the vehicle system also comes from the electromagnetic interference outside the vehicle and the vehicle body. The electromagnetic interference outside the vehicle is the interference when the vehicle passes through various external electromagnetic environments while driving. The static interference of the vehicle body is related to the vehicle as well as the external environment. These two kinds of electromagnetic interference also often occur in the daily operation of vehicles, which is worth noting.