Remaining Capacity Measurement And Reliability Evaluation Of Li/SOCl₂ Battery For Smart Electricity Meter

As an important equipment in power grid construction,smart electricity meter plays an important role and has a large number.Li/SOCl₂ battery is the key backup power supply in smart electricity meter,and its faults account for a very high proportion in all kinds of faults.Taking into account the unclear mechanism of battery capacity degradation,the inapplicable traditional battery capacity measurement method,and the lack of accelerated battery degradation test and reliability evaluation methods combined with actual working conditions,related research is carried out in this paper.The main research contents of this paper are as follows:Firstly,the battery failure and capacity degradation mechanism of smart electricity meters are studied.The structure,characteristics and fault condition of Li/SOCl₂ battery for smart electricity meter were analyzed.Based on the battery hardware peripheral circuit and software design,the possible causes of abnormal battery discharge were analyzed.Based on the electrochemical principle and characteristics of the Li/SOCl₂ battery,the capacity degradation mechanism was studied.Secondly,the capacity measurement method of Li/SOCl₂ battery based on pulse load test is studied.By analyzing the impedance composition of the battery,the constant load pulse test and passivation fast elimination method for Li/SOCl₂ battery of smart electricity meter are designed,and the influence of battery passivation and ambient temperature on capacity characteristics is studied.According to the battery voltage response,the capacity feature is extracted,and the battery measurement model of capacity feature remaining capacity is established.The battery tests with different storage times and various load conditions were designed to verify the accuracy of the method.This method provides a basis for reliability evaluation research and a new technical means for rapid non-destructive testing of primary battery capacity.Then,the accelerated degradation test method of the Li/SOCl₂ battery is studied and the corresponding test system is developed.By analyzing the influence of the main environmental stress in the battery mission profile on the capacity degradation process,reliability accelerated degradation test scheme is designed with temperature as the test stress,and a test system is developed to simulate the actual power consumption mode and power consumption of smart electricity meters.After 24 weeks of temperature accelerated battery capacity degradation accelerated test,the obtained test data provide the basis for the reliability evaluation of the Li/SOCl₂ battery.Finally,the life prediction and reliability evaluation of the Li/SOCl₂ battery is studied.According to the results of temperature accelerated battery capacity degradation,a half failure physical degradation model based on capacity degradation data was established,and experimental data verify the accuracy of the model.Combined with the initial dispersion of battery capacity,the life and reliability of the battery in the state of no power consumption current influence and working state are evaluated,and the life and reliability evaluation results of Li/SOCl₂ battery task profile are given,which can provide a reference for reducing the fault of smart electricity meter battery and timely battery replacement.