Typical failure mode analysis of charging pile cables: 1. Twisted and bulging cables Charging cables will inevitably be twisted, bent and dragged during use. Over time, as the material ages or the user handles it incorrectly, some areas on the cable can develop bulges. Cut off the cable in the bulging area, and it can be found that the insulation core is dislocated and twisted. Although the bulging of the cable will not cause safety problems in subsequent normal use if the outer sheath is not damaged, but due to the bending and misalignment of the inner core, the core is broken and damaged, resulting in cable failure or an increase in resistance value, which may lead to overheating hazards wait. 2. The sheath of the cable is cracked. Most of the charging cables are outdoor facilities. After long-term use, the sheath will crack due to aging, bending and wear. This situation is mainly concentrated on cables with large cross-sections. In addition, most of the charging cables on the market are made of TPE material insulation sheaths due to cost reasons, not TPU materials, and the insulation sheaths of such materials are more likely to lose the unique properties of cables in low temperature environments.“flexibility”, become hard and brittle, easy to break, and cause safety hazards. 3. The signal line is disconnected. In the charging cable, due to the large difference between the main line core and the signal line core interface, the signal line core is often more prone to breakage when they are bent under the same surface tension, resulting in the charging process. The communication in the middle is blocked, and the control of the charging process fails, causing a series of problems such as overcharging, insufficient power supply, and failure of protective devices, which lead to safety accidents in the charging process. In addition, although the signal line is easier to damage than the main core, the current relevant standards do not require monitoring and testing for this, and the lack of detection devices makes it more difficult to detect cable failures caused by signal line breakage. Hidden, the difficulty of troubleshooting after the problem occurs is relatively large. The above three common charging cable failure modes of charging piles, obviously, the breakage of the signal line is more hidden and frequent than the other two. Even in the case of mode 1 and mode 2, the signal line is still There is a higher risk of damage. When the main core of the charging cable is intact and the signal communication cable is damaged, if the charging process is still going on, the controller cannot correctly adjust the output power because it cannot get the battery status fed back from the battery terminal. The potential safety hazards in the controlled charging process are obvious; secondly, even if the controller reacts to stop the charging process when the communication signal is disconnected, then in the subsequent troubleshooting process, it is still necessary to detect the signal line again to determine whether the signal line is broken is the problem spot where the cable fails. This step can be determined in the process of the controller taking measures to deal with the breakage of the signal line. This function is realized by adding communication signal detection during the charging process of the electric vehicle. .
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