Base On The Fiber Bragg Grating Sensor For Detecting The Residual Capacity Of The Lead-acid Battery

At present, it is paid more attention for the environmental and energy problems. The fuel oil vehicle is denounced by its high energy consumption and the high pollution. Electric vehicles have been developed for it's benefit of zero emission and low noise. As the battery charge and discharge is a complex electrochemical process.many companies use the logo on their claims to have 10 years of float life, but in practice, due to the simple charging, the battery life of less than the actual float half of its claims. Meanwhile, in practice, these batteries are often multiple series. Electric vehicle battery system for the residual capacity enter the practical stage. The research and used of the system for the residual capacity of the Lead-acid Battery is an important means to effectively extend the battery life, which can not only be to prevent excessive battery discharge or over charge, but also for electric vehicles during the exercise played an important role in motor gasoline table.This paper does research on lead-acid battery. First, describes the electrochemistry characteristic of lead-acid battery, point out the factors of affecting residual capacity(RC) and the difficulties of estimating stage-of-charge. Based on these, this paper raise a new approach to estimate SOC based on the phase shift FBG made by etched. According to the Fiber Bragg Grating refractive index law, refractive index sensor based on phase shift FBG made by etched FBG for measurement of the residual capacity of lead-acid battery is presented. The etched FBG refractive index is related to the measurement on the electrolyte's concentration ,at the same time electrolyte's concentration is related to the residual capacity of lead-acid battery on a corresponding function relation. With the actual needs of the subject and made the following specific tasks:(1) Analysis of the basic working principle of lead-acid batteries, the basic electrical properties of lead-acid batteries, charge and discharge characteristics of battery capacity and its impact factor;(2) In-depth study on its concentration of the refractive index of FBG sensing principle and the principle of evanescent wave fiber-depth ,and to understand the fiber etching process to produce corrosion of equipment, the corrosion test grating to prepare for the relevant measurement;(3) Through experimental research to product the sensors, and through its own characteristics to eliminate the influence of temperature on the signal;(4) Doing a great deal of lead-acid battery charge and discharge test, and making analysis of experimental data to prepare for the follow-up. By the theory of the sensor, the working principle and the composition of the analysis, design a line of lead-acid battery residual capacity detection optical fiber sensor system.This sensor has many merits such as precise measurement,sensitive reaction etc.