CN-116331062-B - Battery SOC dynamic correction method and system and vehicle with same

CN116331062BCN 116331062 BCN116331062 BCN 116331062BCN-116331062-B

Abstract

The invention provides a battery SOC dynamic correction method, a system and a vehicle with the same, wherein the battery SOC dynamic correction method comprises the following steps of judging the range of displaying the SOC; and adjusting the correction rate of the SOC by increasing or decreasing the current according to the range of the display SOC so as to make the display SOC equal to the real SOC. According to the battery SOC dynamic correction method provided by the embodiment of the invention, different correction rates can be adopted in different SOC ranges according to the actual SOC characteristics and actual charge and discharge service conditions of the battery, so that the display SOC of the large charge and discharge power type battery is more accurate.

Inventors

WANG LEI
WAN XIN
LI DANDONG

Assignees

北京汽车集团越野车有限公司

Dates

Publication Date: 20260505
Application Date: 20230104

Claims (3)

1. The dynamic correction method for the battery SOC is characterized by comprising the following steps of: Judging and displaying the range of the SOC; According to the range of the display SOC, the correction rate of the SOC is adjusted by increasing or decreasing the current so that the display SOC is equal to the real SOC; The correction rate is 5% if the display SOC is not more than 35%, 2% if the display SOC is not more than 35% < 45%, 1% if the display SOC is not more than 45% < 75%, 2% if the display SOC is not more than 75% but less than 85%, and 5% if the display SOC is not less than 85%.
2. A battery SOC dynamic correction system, comprising: The judging module is used for judging the range of the display SOC; The correction module is connected with the judging module, and adjusts the correction rate of the SOC by increasing or decreasing the current according to the range of the display SOC so as to enable the display SOC to be equal to the real SOC; The correction rate is 5% if the display SOC is not more than 35%, 2% if the display SOC is not more than 35% < 45%, 1% if the display SOC is not more than 45% < 75%, 2% if the display SOC is not more than 75% but less than 85%, and 5% if the display SOC is not less than 85%.
3. An automobile comprising the battery SOC dynamic correction system as claimed in claim 2.

Description

Battery SOC dynamic correction method and system and vehicle with same Technical Field The invention relates to the technical field of new energy batteries, in particular to a battery SOC dynamic correction method and system and a vehicle with the same. Background The development of automobiles is advanced from a pure fuel stage to a new energy generation stage of hybrid power of oil and electricity and pure electric. A light mixing project adopts a power assembly of a 2.0T+48V light mixing system. The light mixing system is introduced to make up the delay of the intervening work of the supercharger on one hand, and on the other hand, the engine is enabled to run near the enrichment line more through the torque output by IBSG, so that the engine runs in a high-efficiency area to reduce the oil consumption and the carbon emission. The state of a 48V lithium battery in a light hybrid system is therefore critical to system operation. The key parameter for representing the working capacity of the lithium battery is the state of charge (SOC) of the battery, and the lithium battery selected by the light mixing system is a lithium iron phosphate cell with 1-14 strings, and has the characteristics of small electric quantity (0.4 Kw.h) and large charge and discharge power (13 kW instantaneously) during use. In the use process of the lithium battery, the fluctuation amplitude of the SOC is larger, so that the accurate response of the SOC state is very important. The lithium battery SOC is divided into a display SOC and a real SOC, the real SOC represents the actual state of charge of the battery and can be obtained by looking up a table through an OCV curve according to the internal resistance and voltage change characteristics of the battery core, but the premise that the battery core is required to stand still and no charge and discharge current is required to be met by looking up the table through the OCV curve is that the battery core is difficult to meet the working conditions in the use process of the lithium battery, and the display SOC is generally obtained through ampere-hour integral calculation according to the actual condition of the charge and discharge current in the use process. However, ampere-hour integration is influenced by the sampling precision of the current sensor and the superposition error of an integration algorithm in the calculation process, so that deviation exists between the real SOC and the display SOC. Disclosure of Invention The technical problem to be solved by the embodiment of the invention is that a large deviation exists between the display SOC and the real SOC, and the correction is difficult. In view of the above, the present invention provides a method for dynamically correcting SOC of a battery, comprising the steps of: Judging and displaying the range of the SOC; And adjusting the correction rate of the SOC by increasing or decreasing the current according to the range of the display SOC so as to make the display SOC equal to the real SOC. The battery SOC dynamic correction method according to the embodiment of the invention can also comprise the following technical characteristics: Further, the correction rate is 5% if the display SOC is not more than 35%, 2% if the display SOC is not more than 35% < 45%, 1% if the display SOC is not more than 45% <75%, 2% if the display SOC is not more than 75% and 5% if the display SOC is not less than 85%. According to a second aspect of the present invention, a battery SOC dynamic correction system includes: The judging module is used for judging the range of the display SOC; The correction module is connected with the judging module, and adjusts the correction rate of the SOC by increasing or decreasing the current according to the range of the display SOC so that the display SOC is equal to the real SOC. Further, the correction rate is 5% if the display SOC is not more than 35%, 2% if the display SOC is not more than 35% < 45%, 1% if the display SOC is not more than 45% <75%, 2% if the display SOC is not more than 75% and 5% if the display SOC is not less than 85%. The vehicle according to the second aspect of the invention includes the battery SOC dynamic correction system described in the above embodiment. The technical scheme of the invention has at least the following technical effects: According to the battery SOC dynamic correction method provided by the embodiment of the invention, different correction rates can be adopted in different SOC ranges according to the actual SOC characteristics and actual charge and discharge service conditions of the battery, so that the display SOC of the large charge and discharge power type battery is more accurate. Drawings FIG. 1 is a flowchart of a method for dynamically modifying a battery SOC according to an embodiment of the present invention; FIG. 2 is a graph of OCV according to an embodiment of the present invention; FIG. 3 is a graph of SOC according to an embodiment of the present in