Method for estimating lithium ion battery remaining available capacity

Abstract

The invention discloses a method for estimating lithium ion battery remaining available capacity. The method comprises the steps of acquiring standard temperature, a standard discharging current and battery internal resistance from a battery instruction book, acquiring battery nominal capacity based on battery bench testing data, drawing a temperature-current-SOC three-dimensional surface, estimating the remaining available capacity of a battery under a battery future current according to the current battery temperature, the current battery SOC, the battery standard nominal capacity, the battery internal resistance, the battery future current and the temperature-current-SOC three-dimensional surface, and calculating the battery remaining battery capacity according to the remaining available capacity, a battery current end voltage, the battery internal resistance and the battery future current. According to the method for estimating the lithium ion battery remaining available capacity, influences on the lithium ion battery remaining available capacity by the battery discharging current, the battery temperature and the battery internal resistance are taken into solid consideration, an accurate estimation value of the lithium ion battery remaining available capacity can be offered, and the estimation value of the lithium ion battery remaining available capacity is further used for estimation of remaining mileage of an electric automobile and automobile overall energy management.

Description

technical field [0001] The invention belongs to the field of battery management and battery state estimation, and in particular relates to a method for estimating the remaining available energy of a lithium ion battery. Background technique [0002] At present, global oil resources are becoming increasingly depleted, environmental problems such as the greenhouse effect are becoming more severe, fuel prices are increasing day by day, and emission regulations are becoming more and more stringent. Compared with traditional fuel vehicles, electric vehicles have great advantages in driving economy and environmental friendliness, and have good development prospects. However, electric vehicles have a shorter driving range and are less convenient for daily use. The driving range of an electric vehicle depends on the remaining available energy of the power battery and the energy consumption of the whole vehicle. Among them, the remaining available energy of the power battery involv...

AI Technical Summary

Problems solved by technology

[0004] At present, there are some calculation methods for the remaining available energy of electric vehicle power batteries, but these methods are relatively simple to calculate the remaining available energy of the battery, and will cause large estimation errors when used in real vehicle conditions

Specifically, in the calculation of the remaining available energy of the battery, the previous methods mostly use the method of directly multiplying the battery state of charge (SOC), the battery nominal capacity and the current terminal voltage, and rarely consider the battery temperature, future discharge current, and future discharge process. The temperature rise of the battery in the battery, the voltage change in the future discharge process, the internal resistance of the battery and other factors will affect the estimation accuracy of the remaining available energy of the battery.

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