Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (11): 4078-4088.doi: 10.19799/j.cnki.2095-4239.2024.0434

• Energy Storage Test: Methods and Evaluation • Previous Articles     Next Articles

State of charge estimation of lithium batteries using adaptive unscented H infinity filter

Wei QIAN1,2(), Dazhong ZHAO1, Xiangwei GUO1,2, Yafeng WANG1, Wenjing LI1   

  1. 1.School of Electrical Engineering and Automation, Henan Polytechnic University, Jiaozuo 454003, Henan, China
    2.Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment, Jiaozuo 454003, Henan, China
  • Received:2024-05-16 Revised:2024-05-28 Online:2024-11-28 Published:2024-11-27
  • Contact: Wei QIAN E-mail:qwei@hpu.edu.cn

Abstract:

The state of charge (SOC) is a crucial metric for assessing the remaining power of lithium batteries, playing a significant role in optimizing battery usage and ensuring safety. To address the challenge of SOC estimation using the H infinity frilter (HIF), which offers high robustness but limited accuracy, this study proposes an adaptive unscented H infinity filter (AU_HIF) to enhance estimation precision. The dual polarization equivalent circuit model, known for its balanced accuracy and complexity, is selected to develop the new estimation algorithm. The unscented Kalman filter (UKF), which is more suitable for nonlinear state estimation compared to the traditional extended Kalman filter, is combined with a novel fading factor designed based on the prior error covariance matrix. This design minimizes the impact of outdated measurements on estimation results, improving the tracking capability and accuracy of the filtering algorithm. The effectiveness of the proposed AU_HIF is validated through simulations using data collected from a custom-built experimental platform. Results demonstrate that the adaptive unscented HIF outperforms traditional H infinity filtering, the standard UKF, and other modified H infinity filtering algorithms in terms of estimation accuracy and robustness. This research significantly enhances SOC estimation for battery systems used in new energy vehicles and energy storage power stations.

Key words: lithium battery, SOC, H infinity filter, dual polarization model, fading factor

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