State of charge SOC correction method and device for power battery

Abstract

The invention discloses an SOC (state of charge) correcting method of a power battery. The SOC correcting method comprises the following steps: acquiring the estimation value and the exact value of the current SOC of the power battery; comparing the estimation value and the exact value, and judging whether the calculation value of the real-time SOC of the power battery, obtained based on the estimation value, needs to be corrected according to the compared result; if so, generating a correction coefficient according to the state of the power battery and the estimation value and the exact value of the current SOC of the power battery; and calculating the correction value of the real-time SOC of the power battery according to the input and output electricity quantity of the power battery, the correction coefficient and the estimation value of the power battery collected in real time. According to the method provided by the embodiment of the invention, the SOC value deviating from the exact value can be corrected smoothly to be relative exact SOC value, so that the method has the advantages that drivers cannot perceive the correction so as to be prevented from feeling uneasy. The invention also discloses an SOC correcting device of the power battery.

Description

technical field [0001] The invention relates to the technical field of automobile manufacturing, in particular to a method and device for correcting the state of charge SOC of a power battery. Background technique [0002] In electric vehicle technology, the SOC (state of charge) estimation of the power battery is a key link. Correctly displaying the current SOC of the battery system can help the driver estimate the remaining mileage, so it is very important. The commonly used SOC estimation method is based on the power integral, plus measures such as open circuit voltage correction and charging correction to eliminate the cumulative error, but when the accurate SOC point is detected (usually the point where the SOC is 0% or for 100% point) and use it as the new integration starting point, if there is a large difference from the original calculated old SOC value, directly use the new integration starting point, although it is more accurate, but there will be SOC The jump of...

AI Technical Summary

Problems solved by technology

[0007] The idea of ​​the existing technology (open-circuit voltage-assisted power accumulation method) is to estimate SOC based on accumulating the input and output power Ah of the battery system, but when the open-circuit voltage is corrected, due to the difference between the old SOC initial value and the new SOC initial value There may be a relatively large difference between them, and the SOC will change from the old initial value to the new initial value (there may be no driving or charging during the mutation process), which will cause the driver's uneasiness, thinking that the SOC pointer is jumping unpredictably, Cause complaints from drivers and affect the reputation of the vehicle

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