Battery capacity consistency estimation method and system

Abstract

The invention provides a battery capacity consistency estimation method and system, and the method comprises the steps: inputting a plurality of battery capacity observation values into a consistency statistical model, and obtaining a battery capacity distribution statistical characteristic and an abnormal value recognition result; verifying the estimation result of the consistency statistical model, and judging whether the battery capacity distribution statistical characteristics described by the estimation result of the consistency statistical model are consistent with the distribution statistical characteristics of the actual battery capacity observation value or not based on the verification result; and using an estimation result of the consistency statistical model to evaluate battery capacity consistency and identify an abnormal value of battery capacity distribution. According to the method, the consistency statistical model is established based on the three-parameter Weibull model, the improved Weibull parameter estimation method is adopted to obtain the estimation result of the Weibull characteristic parameters, the method is used for evaluating the battery capacity consistency and identifying the abnormal value of battery capacity distribution, the model calculation amount can be greatly reduced, the observation precision is improved, and the influence of abnormal variables on the estimation result is avoided.

Description

technical field [0001] The invention relates to the technical field of battery detection, and in particular, to a method and system for estimating battery capacity consistency. Background technique [0002] Batteries have large consistency differences in battery capacity due to manufacturing deviations and different battery performance decay rates during use. Under conventional manufacturing conditions, the battery capacity obeys a normal distribution, that is, a symmetrical distribution on both sides of the probability peak. The consistency characteristics of the battery capacity distribution can be obtained through the parameters of the Gaussian probability model. However, when an abnormality occurs in the battery preparation process or use process, the battery capacity distribution is no longer symmetrical, and turns from a normal distribution to a skewed distribution. collection. Usually, the Weibull probability model can obtain the asymmetric characteristics of random...

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Problems solved by technology

[0004] Obviously, the above scheme has the following defects: due to the existence of the position parameter C, the Weibull model parameter estimation is more complicated. If the value of C cannot be accurately estimated, it will affect the estimation results of the size parameter A value and the shape parameter B value, resulting in random Identification error of variable statistical characteristics

In practical applications, when there are too small abnormal variables in the random variable, the Weibull parameter estimation result will have a large deviation due to the too small estimated value of the position parameter C, which leads to the inability to accurately predict the statistical characteristics of the random variable distribution

At present, the existing Weibull distribution estimation method cannot rule out the interference of abnormal variables on the parameter estimation results, and the estimation results have low reliability, which is difficult to meet the accuracy requirements in practical applications.

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