Method for fault diagnosis on basis of storage battery state of charge (SOC) and state of health (SOH)

Abstract

The invention discloses a method for fault diagnosis on the basis of storage battery state of charge (SOC) and state of health (SOH), which comprises the steps of: sequentially calculating all the monomer SOC and SOH which form all the battery modules, the equivalent SOC and SOH of all the modules which form a battery pack, and the equivalent SOC and SOH of the whole battery pack, and judging whether a storage battery discharges or not. The method for fault diagnosis online identifies and calculates the equivalent SOC and SOH of the whole battery pack, and accordingly, the real-time fault diagnosis is realized.

Description

technical field [0001] The invention relates to a fault diagnosis method, in particular to a centralized / distributed fault detection method suitable for electric vehicles. Background technique [0002] The electric vehicle battery pack is composed of dozens or even hundreds of single cells or battery modules in series. One of the prominent problems in the use of batteries is the inconsistency between the batteries. The single cells with poor performance in the battery pack directly affect the capacity and remaining energy of the battery pack, and determine the performance and life of the entire battery pack. Battery state of charge (SOC, state of charge) and state of health (SOH, state of health) are important parameters that reflect the working state and health state of single cells and battery packs. The existing problems include: (1) The definition of SOC and SOH is only for the single battery, and the SOC and SOH of the battery pack are not clearly defined; There is a ...

AI Technical Summary

Problems solved by technology

The existing problems include: (1) The definition of SOC and SOH is only for the single battery, and the SOC and SOH of the battery pack are not clearly defined; There is a large deviation between the SOC and SOH values ​​of the battery and the actual value; (3) The SOC and SOH of the single battery cannot accurately reflect the working status and health status of the battery pack

[0003] It is difficult to detect the slow changes of single cells only through parameters such as battery pack bus voltage, current, and battery box temperature, including the aging of the single cells themselves and the cumulative effect caused by the consistency of the single cells, and it is impossible to detect the single cells and the actual capacity of the battery pack

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