Method and system for judging performance of electric automobile power battery

Abstract

The invention discloses a method and system for judging the performance of an electric automobile power battery. The method includes obtaining the proportion of voltage of each individual battery in the power battery to the total voltage of the power battery at a measuring moment, and recording as an individual proportion, wherein the measuring moment is any moment; calculating a difference value between an ideal weight and the individual weight to obtain a weight deviation of the individual battery; calculating the weight deviations of all the individual batteries, and building a weight deviation matrix; calculating a mean value and standard deviation of the weight deviation matrix; calculating an overall weight deviation; and according to the mean value of the weight deviation matrix, the standard deviation of the weight deviation matrix and the overall weight deviation, judging the performance of the power battery. The method and system for judging the performance of the electric automobile power battery establishes a system for evaluating the difference of the performance of individual batteries in the same electric automobile and a system for evaluating the performance of power batteries of different electric automobiles.

Description

technical field [0001] The invention relates to the field of performance evaluation of electric vehicle power batteries, in particular to a method and system for judging the performance of electric vehicle power batteries. Background technique [0002] In the face of severe energy and environmental crises, countries around the world have recognized the importance of energy conservation and emission reduction from a strategic perspective, and have taken the development of clean and efficient electric vehicles as an important measure. As the only energy source of electric vehicles, especially pure electric vehicles, the power battery system has become one of the main sources of failure of electric vehicles due to reasons such as technology, working conditions and use environment. [0003] The electric vehicle power battery pack consists of multiple single cells connected in series or in parallel. The factors affecting the life of the battery pack include the consistency level ...

AI Technical Summary

Problems solved by technology

[0005] This algorithm aims at the consistency of the lithium-ion battery pack of an electric vehicle, compares the consistency of different monomers, and cannot compare the consistency of battery voltages of different vehicles; it is not clear which type of battery consistency to judge, it is voltage consistency The patent does not clearly state the consistency, internal resistance consistency or internal group consistency; in addition, in the real situation of pure electric vehicles, the actual power demand must fluctuate, such as acceleration and braking, etc., it is difficult to determine the discharge rate, and The patent only proposes standard deviations under three discharge rates (1C, 2C, 3C), which obviously cannot meet the actual frequent charging and discharging conditions.

[0006] Another patent related to the present invention, "Lithium-ion Monomer Battery Consistency Evaluation System and Method", on the voltage consistency, uses a simple monomer voltage and the average value of N monomer voltages to make a difference, and uses the difference value To replace the consistency, it is impossible to judge the voltage consistency of different cars

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