Battery residual capacity evaluation method

Abstract

The invention discloses a battery residual capacity evaluation method, comprising steps of calculating the battery residual capacity according to the charge-discharge current of a battery pack, ;detecting open circuit voltage OCV if the static state of the storage pack exceeds a preset period, ;calculating the variation quantity of the battery residual capacity in each period and calculating the variation quantity of the battery residual capacity through checking a meter by lookup according to the open circuit voltage, ;calculating the attenuation weight value of the battery capacity according to the two variable quantities calculated from the calculation,and calculating the current battery residual capacity according to the weight value and the battery residual capacity of the previous moment. The method expresses the attenuation trend of the battery capacity through the weight value, and introduces the weight value during the calculation of the residual battery capacity while correcting the errors so as to realize the accurate estimation on the battery residual capacity. The method can perform residual capacity updating when the battery management system accords with the condition. The battery residual capacity estimation method, can be widely applied in the battery pack management field.

Description

technical field [0001] The invention relates to the field of battery system management, in particular to a battery remaining capacity estimation method. Background technique [0002] In the battery management system of electric vehicles, it is necessary to accurately estimate the remaining capacity (SOC) of the battery pack. Only by knowing the current power consumption, can we estimate the mileage that the vehicle can continue to drive. If the SOC cannot be accurately estimated, there may be a danger of the battery pack over-discharging the cells, causing the battery pack cells to be too low and causing irreversible damage to the battery itself, which will have a great impact on the battery life. In the case of accurately estimating the SOC, it is possible to know how much electricity is charged and how much electricity can be discharged. Just like how much gasoline can be added to a traditional gasoline car, it can accurately estimate how far the vehicle can travel. [...

AI Technical Summary

Problems solved by technology

From these factors, it is still not possible to judge the SOC of the battery well. The problem is to consider the high temperature storage life of the battery, the battery load, the depth of charge and discharge, and the charge and discharge rate.

Unable to accurately estimate the SOC, it is likely to cause the battery to be under heavy load, large charge and discharge depth, etc., which will have a great impact on the life of the battery

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