光纤铅酸蓄电池安全在线监测技术研究

Research on optical fiber lead-acid battery safety on-line monitoring technology

铅酸蓄电池的电解液变化对于电池安全运行状态至关重要,研究植入性传感技术有助于精确监控蓄电池内部电解液变化等过程,及时在线获得蓄电池的实时工作性能与状态,在蓄电池安全监测领域具有重要意义。文章提出并设计了一种基于全光纤法布里-珀罗(Fabry-Perot,FP)干涉仪的液体浓度传感器,其探头是由两段单模光纤和一段U形毛细石英玻璃管构成的开放式FP腔,可以使液体轻松进入空腔,不易形成气泡。该结构具有耐强酸强碱、侵入性低、体积小、抗电磁干扰和绝缘体特性等优势,可植入铅酸蓄电池内部,实现对电解液中的硫酸溶液浓度的实时在线监测。结果表明:在硫酸为0~30%的体积分数范围内,FP腔的有效腔长和硫酸溶液的体积分数具有良好的线性度,其拟合系数达0.995,硫酸溶液的体积分数测量值与真实值之间的最大偏移量<±1.05%。

The electrolyte change of lead-acid battery plays a rucial role in the safe operation status of the battery,and the research of implantable sensing technology can help to precisely control the processes such as electrolyte change inside the battery and obtain the real-time working performance and status of the battery online in time,which has important applications in the field of battery safety monitoring.This paper proposed and designed a liquid concentration sensor based on the all-fiber Fabry-Perot interferometer,whose probe consists of two segments single-mode optical fibers and a U-shaped capillary quartz glass tube to form an open FP cavity,which allows the liquid to enter the cavity easily and is not easy to form air bubbles.The structure has the advantages of strong acid and alkali resistance,low intrusion,small size,anti-electromagnetic interference and insulator characteristics,etc.It can be implanted inside the lead-acid battery for real-time online monitoring of sulfuric acid concentration in electrolyte.The results indicate that the effective cavity length of FP cavity and sulfuric acid concentration has good linearity in the range of sulfuric acid concentration from 0 to 30%,and the fitting coefficient reaches 0.995,and the maximum offset between the measured and real values of sulfuric acid concentration is within±1.05%.