Battery capacity active estimating method for pure electric vehicle

Abstract

The invention relates to a battery capacity active estimating method for a pure electric vehicle. The method is used for performing periodical active estimation on the battery capacity of the pure electric vehicle and comprises the following steps of determining whether a battery capacity periodical estimation time of the pure electric vehicle is reached, if yes, entering a next step, and otherwise, returning to determining; determining whether a first SOC value of the battery can be accurately acquired, if yes, acquiring the first SOC value, and otherwise, abandoning estimation; calculating a total current integral quantity of the pure electric vehicle in an operation state; determining whether a second SOC value can be estimated according to the battery offline time of the pure electric vehicle, if yes, estimating the second SOC value, and otherwise, abandoning estimation; and performing calculation according to the first SOC value, the total current integral quantity and the second SOC vale, thereby obtaining the battery capacity estimated value of the pure electric vehicle. Compared with the prior art, the battery capacity active estimating method has advantages of high estimation precision, easy realization, high adaptability, etc.

Description

technical field [0001] The invention relates to the field of automobile batteries, in particular to an active battery capacity estimation method for pure electric vehicles. Background technique [0002] There are many high-voltage electrical components in electric vehicles, such as high-voltage battery packs, high-voltage junction boxes, motor controllers, air-conditioning controllers, DC / DC, chargers, etc. The power battery is one of the most critical components, and the performance of the power battery usually becomes weaker with the degree of use and the time of use and storage. This weakening has two manifestations: battery capacity changes (decreases), and charge and discharge power capability changes (decreases) at the same storage level and temperature. In the industry, for battery capacity, a loss of more than 20% generally indicates that the battery no longer has sufficient capacity. [0003] If the change of battery capacity cannot be estimated effectively and ac...

AI Technical Summary

Problems solved by technology

Due to its relatively strict requirements for OCV acquisition, it may not be able to learn the battery capacity in time in practical applications

[0006] The existing capacity calculation based on the second method does not take into account the special characteristics of pure electric vehicles: pure electric vehicles must be charged after a period of use, so the existing calculation method, when obtaining the second OCV It will be affected by leakage, current balance, etc., which will reduce the accuracy of capacity calculation

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