电池管理系统允许用户监控电池组中的单个电池。由于电池组一起工作,向负载释放能量,保持整个电池组的稳定性是至关重要的。
这就是电池管理系统(BMS)发挥作用的地方。BMS允许持续监测、收集并向外部界面传递信息,用户可以观察每个电池的状态和整个电池组的健康状况。BMS监测和管理电池组,以便 保护它不受损害,延长其寿命,并使电池在其安全范围内运行。 这些功能是效率、可靠性和安全性的关键。
BMS测量的是什么?
一个BMS可以测量不同的数字,如 电流、电压、温度和库仑数. 通过这些测量,系统可以评估电池的健康状况,并根据需要重新调整操作以保护电池组。
例如,在给定的负载下,电池电压下降可以表明内阻的增加。然后,这可以指向干涸、腐蚀、板分离或其他诊断。
一个电池的温度突然升高可能表明整个电池组内可能出现热失控事件。然后,BMS可以停止能量的流动,并提醒用户注意潜在的问题,以便在它失去控制之前得到控制。
库仑计数可以帮助估计一个电池的可用容量。这是通过测量充电/放电周期中离开和进入电池的能量来实现的。与一个新的电池单元相比,在一个完整的循环中,库仑计数的减少表明电池容量的下降。
用BMS可以推断出哪些指标?
State of charge (SoC) and state of health (SoH) are important indicators for assessing the usability and capabilities of a battery. Together the SoC and SoH provide a state of function, an overview of the battery and the pack’s capabilities as a whole.
充电状态可能是一个人所遇到的最直接和最常见的衡量标准。手机或笔记本电脑上的电池百分比就是充电状态。在 电动汽车电池, the SoC is used to determine the remaining range left of the car before it needs to be recharged. This, however, by itself, is not indicative of the overall health of the battery. While SoC can show the short term capability of the battery — showing how much energy there is left — it cannot indicate the true capacity of the battery cell or pack. Cell capacity decreases with age so while SoC may read 100%, after a while the true capacity is likely less than that.
尽管如此,SoC仍然是管理电池的一个重要措施。例如,需要知道电池链中各个电池的SoC,以便在电池组中平衡各电池的负载。
Complimentary to SoC, State of Health measures the long-term capabilities of the battery pack. Taking into account charge acceptance, internal resistance, voltage, and self discharge, SoH is an estimation of how much longer a battery can operate optimally. It is usually measured against a fresh battery cell in order to infer the cell’s position within its lifecycle.
没有标准参数来表示SoH,因为它取决于电池单元的功能和应用。不同的参数,如电池电阻或自放电,可以单独加权以评估整体的SoH。
由于SoH通常是针对新电池测量的,BMS必须保持电池初始条件的记录和电池整个生命周期的测量记录,以便更准确地指示电池的健康状况。
为什么BMS很重要?
BMS不仅在显示电池的健康状况方面很重要,而且还能在运行中保护电池。
每个电池单元和化学成分都有电压、温度和电流范围,它可以在这些范围内安全运行。当一个电池低于或超过这些范围时,它可以被BMS检测和控制。例如,锂是一种高活性物质;因此,BMS应监测每个锂电芯,以确保其在预定的限度内运行。这可以保持电池的安全,并在长期内保存它。
Another important safety feature of a BMS is cell balancing. Individual cells within a battery pack do not operate equally. One cell may be weaker or stronger than the other, charging or discharging faster than others within the chain. Without proper compensation, this could degrade the health of the overall pack. If one cell short circuits or fails, this affects the stability of the whole pack. Cell balancing equalizes the charge between individual cells based on each cell’s capability. The BMS helps to monitor and control the charge demanded from each cell in the chain, ensuring that SoC remains evenly distributed.
BMS在电池测试中的作用
BMS在以下方面具有关键作用 电池组测试 以监测每个单独电池的状态及其与整个电池组的运作。它可以帮助检测电池组中的故障和弱点,以及更好地监测整个测试过程中电流、电压、温度和其他参数的变化。SoC和SoH是测试中的重要指标,以了解电池在整个充电/放电周期中的表现。良好 电池测试软件 will be able to communicate these statistics with external interfaces to give researchers a good understanding of the battery pack’s operations.