A method for detecting and locating thermal anomalies of cylindrical lithium-ion batteries

Abstract

The invention discloses a thermal abnormality detection and positioning method of a cylindrical lithium-ion battery, comprising: establishing a cylindrical battery temperature spatial distribution model; obtaining the normalized spatial position and time amount through coordinate transformation and establishing when disturbances and thermal abnormalities exist Normalized temperature spatial distribution model; identify the parameters of the normalized temperature spatial distribution model according to the preset optimization objective function; collect battery surface temperature data, battery current and terminal voltage data, and combine the normalized temperature spatial distribution model Construct the backstepping boundary observer; get the error system according to the backstepping boundary observer and the normalized temperature spatial distribution model, and solve the error system by the successive approximation method to obtain the output temperature estimation error; use cubic spline for the output temperature estimation error The interpolation method obtains the distributed residual amount, which is substituted into the preset residual evaluation function to obtain the evaluation value. When the evaluation value is greater than the preset threshold, it is determined that there is a thermal anomaly at the spatial position.

Description

technical field [0001] The invention belongs to the field of new energy vehicles, in particular to a thermal abnormality detection and positioning method of a cylindrical lithium-ion battery. Background technique [0002] As the core component of new energy vehicles, the safe operation of lithium-ion batteries has attracted extensive attention from academia and industry. On the one hand, thermal effects are the main reason for limiting the capacity of Li-ion batteries; on the other hand, the most common response of batteries to abusive conditions is the generation of heat and gas. Therefore, the diagnosis of thermal anomalies in Li-ion batteries is crucial for safe operation. At present, the mainstream battery thermal anomaly detection is mainly completed by checking the battery surface temperature or terminal voltage exceeding the limit, rather than based on the internal thermodynamic model of the battery. A drawback of this type of method is that the measured value lies ...

AI Technical Summary

Problems solved by technology

The anomaly diagnosis method based on the ordinary differential equation model has observation overflow due to the use of a lumped approximation model, and the diagnostic accuracy for distributed anomalies is not enough

In addition, from the perspective of engineering applications and considering the characteristics of the battery thermal process model, there is no good solution to the distributed anomaly spatial positioning problem based on the PDE (Partial differential equation, partial differential equation) model

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