关键词: 新能源汽车；低温充电；放电过流；动态补偿算法

Abstract: Aiming at the problem of charging system failure of new energy vehicles in a lowtemperature environment below -20 ℃, this article takes the fast charging failure of Jianghuai EV3 battery electric commercial vehicle in a low-temperature environment below -20 ℃ as the entry point, and reveals the energy interaction contradiction mechanism between the battery thermal management system and the charging system. Through fault source tracing, it is found that under low-temperature and low-power conditions, the allowable discharge current of the battery is small, which is significantly out of balance with the working current required by the water heating heater, triggering the discharge overcurrent protection and causing the charging to be interrupted. The article proposes for the first time the precise compensation of energy consumption of water heating heaters based on the dynamic current compensation algorithm. Experimental verification shows that this strategy can be successfully charged in a low-temperature environment below -20 ℃ and has significant technical advantages. The research results have effectively solved the problem of energy coordination and control between battery thermal management requirements and charging systems, providing key technical support for the promotion and application of new energy vehicles in high-latitude cold regions.

Key words: new energy vehicle; low-temperature charging; discharge overcurrent; dynamic compensation algorithm