Estimation method and device of cell aging states and cell management system

Abstract

The invention discloses an estimation method and device of a cell aging states and cell a management system. The method comprises steps of acquiring the current parameter value of a preset cell parameter and acquiring current load voltage of the cell; according to the current parameter value, searching corresponding relation data of experiment load voltage of each aging stage and experiment parameters so as to obtain multiple experiment load voltage; comparing the current load voltage with the experiment load voltage, and determining the aging section where the cell is located currently; carrying out counting processing on the aging section where the cell is located currently so as to obtain counting values and judging whether the sum of the counting values of the aging sections reach a preset threshold; if yes, according to the counting value of each aging section, calculating the aging increasing rate of each aging section; and according to the aging increasing rate of each aging section, estimating the cell aging states. According to the invention, a simple and reliable estimation scheme of the cell aging states based on voltage drop rule statistics of the load voltage of the cell is provided and a problem of complex and unreliable estimation of the cell aging states in the prior art are solved.

Description

technical field [0001] The invention relates to the technical field of power batteries, in particular to a battery aging state estimation method, device and battery management system. Background technique [0002] At present, there are mainly the following methods for judging the aging of power batteries of new energy vehicles: judging by the cumulative number of charge and discharge cycles of the power battery; judging by the cumulative charge and discharge ampere hours (AH); [0003] However, in the process of realizing the embodiments of the present invention, the inventors found that there are at least the following problems in the prior art: the method of judging battery aging by the cumulative number of charging and discharging cycles of the power battery has limitations in applicability and large errors in judgment results, for example, for For non-plug-in hybrid electric vehicles, because the power battery is difficult to fully charge and discharge, it is difficult t...

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Problems solved by technology

[0003] However, in the process of realizing the embodiments of the present invention, the inventors found that there are at least the following problems in the prior art: the method of judging battery aging by the cumulative number of charging and discharging cycles of the power battery has limitations in applicability and large errors in judgment results, for example, for For non-plug-in hybrid electric vehicles, because the power battery is difficult to fully charge and discharge, it is difficult to count the number of charge and discharge cycles; the method of judging battery aging by the accumulated charge and discharge ampere hours (AH), due to the accumulated charge and discharge ampere hours The number cannot truly reflect the aging state of the battery. This method is only an estimation method based on statistics. Theoretically, the higher the accumulated ampere-hours of the battery, the longer the battery usage time, and the aging trend will inevitably appear when the battery is used for a long time. , so the reliability of this estimation method is poor; while the estimation method based on battery capacity and internal resistance is mainly based on the battery circuit model, but the battery circuit model cannot reflect the real electrochemical characteristics of the battery, and the battery In the actual use process, it will be affected by complex factors such as working conditions and the environment, which will cause errors in the battery internal resistance and battery capacity calculated based on the battery model, which will affect the reliability of the estimation of the battery aging state, and the circuit model solution algorithm It is more complex and takes up more computing resources of the controller

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