Computing method for battery electric quantity state

Abstract

A battery electric quantity state calculating method relates to an electric automobile lithium ion battery electric quantity state calculating method, which solves the existing problems that the existing method for calculating the SOC is greatly influenced by the training methods and the training data, has a large amount of data processing, high requirements for the processor performance and a lack of considering the environment temperature and the influence of the cycle number on the battery rated capacity; the results have errors. The method of the invention has the steps that an initialization signal collection system collects the current system parameters and carries out the digital to analog conversion of the collected signals, orderly reads the cycle technical parameters and the resting time parameters, and then selects initial open-circuit voltage; the collected relative parameters are input into a processor to calculate, the results are stored, and a time counter is reset; finally the results are output to display. The calculating method has the advantages of high calculation accuracy and practicality, small data processing amount, low requirements for the processor performance and small errors.

Description

technical field

[0001] The invention relates to a method for calculating the state of charge of a lithium ion battery of an electric vehicle. Background technique

[0002] The state of charge (SOC) of the battery has always been a subject of common concern and research by electric vehicle and battery researchers. In hybrid electric vehicles, SOC is an important basis for the vehicle controller to formulate energy control strategies. SOC, a battery capacity state description parameter, is widely used at home and abroad. The general definition of SOC is to accurately calculate the capacity of the battery, that is, to predict the remaining energy of the battery. SOC is an important parameter to describe the state of the secondary battery. Usually, the SOC when the secondary battery is charged to the point where it can no longer absorb power at a certain temperature is defined as SOC=100%, and the power state when the secondary battery can no longer discharge power is defined. ...

Examples

specific Embodiment approach 1

[0018] Specific implementation mode one: see figure 1 , the method of this embodiment consists of the following steps:

[0019] Step 1, initialize the signal acquisition system 2, and collect the open circuit voltage V of the battery in the power supply system 1 of the current electric vehicle at time t t , working current I t and temperature T t According to the measured open-circuit voltage, query the open-circuit voltage / electricity correspondence table prestored in the memory 3, and obtain the initial electric quantity value Q corresponding to the static open-circuit voltage 0 According to the measured value, query the working temperature / temperature correction coefficient correspondence table stored in the memory 3, and obtain the correction coefficient K T ;

[0020] Step 2, performing analog-to-digital conversion on the collected signal, and inputting it into the memory 3;

[0021] Step 3, read the number of cycles correction parameter K stored in the memory 3 L ,...

technical field

[0001] The invention relates to a method for calculating the state of charge of a lithium ion battery of an electric vehicle. Background technique

[0002] The state of charge (SOC) of the battery has always been a subject of common concern and research by electric vehicle and battery researchers. In hybrid electric vehicles, SOC is an important basis for the vehicle controller to formulate energy control strategies. SOC, a battery capacity state description parameter, is widely used at home and abroad. The general definition of SOC is to accurately calculate the capacity of the battery, that is, to predict the remaining energy of the battery. SOC is an important parameter to describe the state of the secondary battery. Usually, the SOC when the secondary battery is charged to the point where it can no longer absorb power at a certain temperature is defined as SOC=100%, and the power state when the secondary battery can no longer discharge power is defined. ...

Examples

specific Embodiment approach 1

[0018] Specific implementation mode one: see figure 1 , the method of this embodiment consists of the following steps:

[0019] Step 1, initialize the signal acquisition system 2, and collect the open circuit voltage V of the battery in the power supply system 1 of the current electric vehicle at time t t , working current I t and temperature T t According to the measured open-circuit voltage, query the open-circuit voltage / electricity correspondence table prestored in the memory 3, and obtain the initial electric quantity value Q corresponding to the static open-circuit voltage 0 According to the measured value, query the working temperature / temperature correction coefficient correspondence table stored in the memory 3, and obtain the correction coefficient K T ;

[0020] Step 2, performing analog-to-digital conversion on the collected signal, and inputting it into the memory 3;

[0021] Step 3, read the number of cycles correction parameter K stored in the memory 3 L ,...

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