Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

Charge state evaluation method and system of power lithium ion battery

A lithium-ion battery and state of charge technology, applied in the direction of measuring electricity, measuring electrical variables, measuring devices, etc., can solve problems such as divergence in the filtering estimation process, large estimation errors, and changes in noise statistical characteristics

Active Publication Date: 2013-12-11
GUILIN UNIV OF ELECTRONIC TECH
View PDF7 Cites 89 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, as the actual working conditions fluctuate violently, the change of the statistical characteristics of the noise will cause the estimation error to increase, and even the filtering estimation process will diverge.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Charge state evaluation method and system of power lithium ion battery
  • Charge state evaluation method and system of power lithium ion battery
  • Charge state evaluation method and system of power lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0111] Embodiment of the method for estimating the state of charge of a power lithium-ion battery

[0112] The first step, model building, experiment and formula identification model parameters

[0113] I. Build a model

[0114] Establish a third-order RC equivalent circuit model of an equivalent power lithium-ion battery, such as figure 1 shown, the polarization resistance R 1 , R 2 and R 3 respectively and capacitance C 1 、C 2 and C 3 Three RC circuits are formed, and the three RC circuits connected in series are connected in series with the open circuit voltage OCV and ohmic internal resistance R of the power lithium-ion battery. 00 , the terminal voltage of the equivalent circuit model is the output terminal voltage Y of the power lithium-ion battery L .

[0115] The corresponding mathematical model is as follows:

[0116] dU 1 dt ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention is a charge state evaluation method and system of a power lithium ion battery. According to the method, step one is to establish a circuit model of an equivalent battery. Charging and discharging and standing experiments are performed on the battery, and timing sampling is performed so that a voltage time curve is obtained. Model parameters are identified via a formula so that a non-linear relation between an open-circuit voltage OCV and an SoC is obtained. Step two is to obtain an optical estimation value of the SoC by matrixes of state prediction, prediction error variance, filtering gain, state estimation, estimation error variance, etc., according to Kalman algorithm. According to the system, an analog / digital converter, a program storage device, a programmable storage device, a timer and a displayer are respectively connected with a microprocessor. A current sensor and a voltage sensor are respectively connected in a circuit formed by connecting the battery to be tested and a load, and outputs of the current sensor and the voltage sensor are accessed into the analog / digital converter. The programmable storage device stores battery model parameters obtained by the experiments. The program storage device stores estimation program of the method. Estimation precision of the SoC can reach 1%, and the charge state evaluation method and system is more stable; besides, the system provides estimation values of the SoC in real time.

Description

technical field [0001] The invention relates to the technical field of state of charge estimation of automotive power lithium batteries, in particular to a method and system for estimating the state of charge (SoC) of power lithium ion batteries using multi-state decomposition Kalman filtering. Background technique [0002] Power batteries are the key to the development of new energy vehicles. In the field of electric vehicles, lithium-ion batteries are mostly used as power sources. Lithium-ion batteries have the advantages of high energy, long cycle life, no memory effect, safety and pollution-free, fast charging and discharging, and wide operating temperature range. [0003] The state of charge (SoC) of the battery is an important parameter in the power battery management system BMS (Battery Management System), and it is an important parameter to ensure the safe life of the battery. However, SoC estimation is a difficult problem to solve. Due to the uncertainty of battery...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/36
Inventor 党选举伍锡如姜辉杨青张向文许勇刘振丙赵龙阳许凯莫妍陈波
Owner GUILIN UNIV OF ELECTRONIC TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Eureka Blog
Learn More
PatSnap group products