At present, with the rapid development of new energy vehicle technology, Electromagnetic Compatibility (abbreviated as EMC) has become a key indicator for measuring the performance of the entire vehicle. And connectors, as the core components for power and signal transmission, their electromagnetic compatibility is directly related to the stability of vehicle operation.
I. Damage to Signal transmission of connectors Caused by electromagnetic interference
New energy vehicles integrate complex high-voltage power systems and high-frequency signal networks inside. The electromagnetic noise generated by components such as motors and inverters during operation is like invisible "interference waves", which can invade the vehicle's communication lines through the wires and interfaces of connectors. Take the CAN bus connector as an example. When it is subject to electromagnetic interference, the bit error rate of data transmission may increase sharply, causing the on-board control system to receive incorrect instructions and leading to problems such as instrument panel data disorder and misjudgment of autonomous driving assistance functions. Especially in high-speed communication scenarios, such as the transmission of images and radar signals in ADAS systems, even the slightest electromagnetic interference can cause information loss, seriously affecting driving stability.
Ii. Equipment failure risks caused by electromagnetic compatibility defects
Connectors with poor electromagnetic compatibility can play a dual role as both the "source of interference" and the "victim". On the one hand, problems such as fluctuations in the contact resistance of the connector itself and failure of the shielding layer will intensify electromagnetic radiation. On the other hand, the external strong electromagnetic environment (such as the electromagnetic field near the charging pile) will also interfere with the normal operation of the connector in the opposite direction. When the shielding structure design of high-voltage connectors is unreasonable, the leaked electromagnetic field may interfere with the surrounding electronic components, causing the battery management system (BMS) to mistakenly trigger overcurrent protection, and even causing the on-board charger (OBC) to shut down, directly affecting the vehicle's range and charging efficiency.
Iii. Hidden Dangers and Regulatory Compliance Pressure
Electromagnetic interference may break through the insulation protection of the connector, causing unexpected short circuits or leakage. For instance, in the high-voltage system of hybrid models, abnormal currents caused by electromagnetic coupling may break down the insulation materials inside the connectors, posing a threat to drivers and passengers. In addition, regulations on automotive electromagnetic compatibility in countries around the world are becoming increasingly strict. Both the EU CE certification and the Chinese GB/T standard require connectors to pass electromagnetic radiation and anti-interference tests. If enterprises neglect EMC design, they will not only face the risk of product recall, but also may miss the qualification for international market access.
Iv. Response Strategy: Full-process optimization from design to testing
To overcome the challenge of electromagnetic compatibility, the industry is making efforts in three aspects: First, it adopts multi-layer shielding structures and metallized coating processes to enhance the electromagnetic shielding effectiveness of connectors; The second is to optimize the design of the contact piece. By using gold-plated terminals and elastic contacts, the contact impedance is reduced to minimize signal reflection. Thirdly, simulation technology is introduced. During the R&D stage, software such as ANSYS is used to simulate the electromagnetic environment to predict and correct design flaws. Meanwhile, strict EMC tests are carried out throughout the entire production process, including RE (Radiated emission), CE (Conducted emission) and other test items, to ensure that the connectors maintain electromagnetic compatibility performance in an environment ranging from -40 ℃ to 125℃.
