关键词: 动力电池；SOC 估算；电池容量；修正系数

Abstract: The state of charge (SOC) of the battery is the most important parameter of the battery management system (BMS), reflecting the available capacity information of the battery. The SOC cannot be measured directly. Instead, it must be estimated indirectly by combining battery voltage, operating current, and rated capacity. Because the battery capacity is easily affected by temperature, current and other factors, it presents nonlinear dynamic characteristics, which is easy to cause inaccurate SOC estimation. How to estimate SOC accurately is a hot and difficult topic for BMS manufacturers. Based on market demand and development cost, a SOC estimation module with modification of influence factors is developed. The test results show that the accuracy of the module estimation is high, which meets the requirements of commercialization and has a good development reference.

Key words: Power battery; SOC estimation; Battery capacity; Correction factor