Journal of IKEEE (전기전자학회논문지)

Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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Real-time EKF-based SOC estimation using an embedded board for Li-ion batteries

임베디드 보드를 사용한 EKF 기반 실시간 배터리 SOC 추정

  • Lee, Hyuna (Dept. of Electronic Engineering, koreaTech) ;
  • Hong, Seonri (Dept. of Energy ICT Convergence Research, Korea Institute of Energy Research) ;
  • Kang, Moses (Dept. of Energy ICT Convergence Research, Korea Institute of Energy Research) ;
  • Sin, Danbi (Dept. of Computer Engineering, koreaTech) ;
  • Beak, Jongbok (Dept. of Energy ICT Convergence Research, Korea Institute of Energy Research)
  • Received : 2021.12.28
  • Accepted : 2022.03.16
  • Published : 2022.03.31
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Abstract

Accurate SOC estimation is an important indicator of battery operation strategies, and many studies have been conducted. The simulation method which was mainly used in previous studies, is difficult to conduct real-time SOC estimation like real BMS environment. Therefore, this paper aims to implement a real-time battery SOC estimation embedded system and analyze problems that can arise during the verification process. In environment consisting of two Raspberry Pi boards, SOC estimation with the EKF uses data measured by the Simscape battery model. Considering that the operating characteristics of the battery vary depend on the temperature, the results were analyzed at various ambient temperatures. It was confirmed that accurate SOC estimation was performed even when offset fault and packet loss occurred due to communication or sensing problems. This paper proposes a guide for embedded system strategies that enable real-time SOC estimation with errors within 5%.

정확한 SOC 추정은 배터리 운영 전략을 제시하는 중요한 지표로 많은 연구가 진행되었다. 기존 연구에서 검증을 위해 주로 사용되던 시뮬레이션 방식은 실제 BMS 환경처럼 실시간 SOC를 추정하기 어렵다. 따라서 본 논문에서는 실시간 배터리 SOC 추정이 가능한 임베디드 시스템을 구현하고 검증 과정에서 발생 가능한 문제 분석을 목표로 한다. 2개의 라즈베리파이 보드로 구성된 환경은 Simscape 배터리에서 측정된 데이터로 EKF 기반 SOC 추정을 진행한다. 검증 단계에서는 온도에 따라 달라지는 배터리 특성을 고려하여, 다양한 주변 온도에서 결과를 확인하였다. 또 임베디드 환경에서 발생하는 오프셋 오류와 패킷 손실에 대비하여, 문제 상황에서 SOC 추정 성능을 검증하였다. 이를 통해 안정범위의 5%내의 오차를 갖는 실시간 SOC 추정이 가능한 임베디드 시스템 구현을 위한 전략을 제시한다.

Keywords

Acknowledgement

This work was conducted under framework of the Ministry of Trade and Industry&Energy (MOTIE) and Korea Institute of Energy Technology Evaluation and Planning (KETEP) of the Republic of Korea. (No. 20182410105280)

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