Modeling of Open Circuit Voltage Hysteresis for LiFePO 4 Batteries

Paper #:
  • 2015-01-1180

Published:
  • 2015-04-14
DOI:
  • 10.4271/2015-01-1180
Citation:
Zhu, L., Sun, Z., Dai, H., and Wei, X., "Modeling of Open Circuit Voltage Hysteresis for LiFePO4 Batteries," SAE Technical Paper 2015-01-1180, 2015, https://doi.org/10.4271/2015-01-1180.
Pages:
9
Abstract:
This paper aims at accurately modeling the nonlinear hysteretic relationship between open circuit voltage (OCV) and state of charge (SOC) for LiFePO4 batteries. The OCV-SOC hysteresis model is based on the discrete Preisach approach which divides the Preisach triangle into finite squares. To determine the weight of each square, a linear function system is constructed including a series of linear equations formulated at every sample time. This function system can be solved by computer offline. When applying this approach online, the calculated square weight vector is pre-stored in advance. Then through multiple operations with hysteresis state vector of squares updated online at every sampling time, the SOC considering the influence of OCV-SOC hysteresis is predicted. To solve the problem that SOC errors become large for non-training hysteresis input, a novel method based on an online adaptive discrete Preisach model (ADPM) is proposed, which reckons the prior offline weights as initial model parameters and introduces the difference between current derived from the model and the measured current as a feedback to adjust the square weight vector at every sampling time when batteries are in actual applications. Through choosing a proper fixed step factor, the maximum modeling error can be less than 1%. The results prove the efficiency and accuracy of the proposed model which contributes to battery management.
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Select
Price
List
Download
$27.00
Mail
$27.00
Members save up to 40% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Technical Paper / Journal Article
2011-04-12
Book
2015-11-09
Technical Paper / Journal Article
2010-10-25
Technical Paper / Journal Article
2011-04-12
Technical Paper / Journal Article
2011-04-12