The Transactions of the Korean Institute of Power Electronics (전력전자학회논문지)

The Korean Institute of Power Electronics (전력전자학회)
권호 표지
DOI QR코드

DOI QR Code

EV Battery State Estimation using Real-time Driving Data from Various Routes

전기차 주행 데이터에 의한 경로별 배터리 상태 추정

  • Received : 2018.09.29
  • Accepted : 2018.12.05
  • Published : 2019.06.20
Download PDF
⟨ Previous Next ⟩

Abstract

As the number of electric vehicles (EVs) in Jejudo Island increases, the secondary use of EV batteries is becoming increasingly mandatory not only in reducing greenhouse gas emissions but also in promoting resource conservation. For the secondary use of EV batteries, their capacity and performance at the end of automotive service should be evaluated properly. In this study, the battery state information from the on-board diagnostics or OBD2 port was acquired in real time while driving three distinct routes in Jejudo Island, and then the battery operating characteristics were assessed with the driving routes. The route with higher altitude led to higher current output, i.e., higher C-rate, which would reportedly deteriorate state of health (SOH) faster. In addition, the SOH obtained from the battery management system (BMS) of a 2017 Kia Soul EV with a mileage of 55,000 km was 100.2%, which was unexpectedly high. This finding was confirmed by the SOH estimation based on the ratio of the current integral to the change in state of charge. The SOH larger than 100% can be attributed to the rated capacity that was lower than the nominal capacity in EV application. Therefore, considering the driving environment and understanding the SOH estimation process will be beneficial and necessary in evaluating the capacity and performance of retired batteries for post-vehicle applications.

Keywords

JRJJC3_2019_v24n3_139_f0001.png 이미지

Fig. 1. Diagram of battery state information acquisition system.

JRJJC3_2019_v24n3_139_f0002.png 이미지

Fig. 2. EV driving routes.

JRJJC3_2019_v24n3_139_f0003.png 이미지

Fig. 3. Altitude of EV driving routes.

JRJJC3_2019_v24n3_139_f0004.png 이미지

Fig. 4. Voltage, current and SOC during driving along different routes and charging mode.

JRJJC3_2019_v24n3_139_f0005.png 이미지

Fig. 5. Battery voltage output for three routes.

JRJJC3_2019_v24n3_139_f0006.png 이미지

Fig. 6. Battery current output for three routes.

JRJJC3_2019_v24n3_139_f0007.png 이미지

Fig. 7. Battery SOC output for three routes.

JRJJC3_2019_v24n3_139_f0008.png 이미지

Fig. 8. Relative frequency of C-rate in log-scale.

JRJJC3_2019_v24n3_139_f0009.png 이미지

Fig. 9. Equivalent circuit of EV battery.

JRJJC3_2019_v24n3_139_f0010.png 이미지

Fig. 10. Frequency of internal series resistance for three routes.

JRJJC3_2019_v24n3_139_f0011.png 이미지

Fig. 11. Estimated SOC for Sungpanak route.

JRJJC3_2019_v24n3_139_f0012.png 이미지

Fig. 12. SOH estimation for 1100-goji route.

JRJJC3_2019_v24n3_139_f0013.png 이미지

Fig. 13. SOH estimation for Sungpanak route.

JRJJC3_2019_v24n3_139_f0014.png 이미지

Fig. 14. SOH estimation for Haeandoro route.

TABLE I AVERAGE C-RATE OF DISCHARGING AND REGENERATIVE CHARGING MODES FOR THREE ROUTES

JRJJC3_2019_v24n3_139_t0001.png 이미지

TABLE II EV BATTERY SPECIFICATION

JRJJC3_2019_v24n3_139_t0002.png 이미지

References

  1. H. J. Hea, "'EV island' Jejudo, over 10,000 EVs in 5 years," The Hankyoreh internet edition, Retrieved Mar. 13, 2018, from http://www.hani.co.kr/arti/society/area/835867.html#csidx7c76441e46b8970ba6828d11ff6b363.
  2. A. Manthiram, "An outlook on lithium ion battery technology," ACS Cent. Sci., pp. 1063-1080, Mar. 2017. https://doi.org/10.1021/acscentsci.7b00288
  3. J. M. Tarascon, "Key challenges in future Li-battery research," Phil. Trans. R. Soc. A, No. 368, pp. 3227-3241, Jul. 2010.
  4. N. Jiao and S. Evans, “Secondary use of electric vehicle batteries and potential impacts on business models,” Journal of Industrial and Production Engineering, Vol. 33, No. 5, pp. 348-354, 2016. https://doi.org/10.1080/21681015.2016.1172125
  5. H. J. Lee, J. H. Park, and J. Kim, "Research of the advanced SOC estimation method for the efficient recycling of the retired Lithium-ion battery," KIPE Power Electronics Conference, pp. 54-55. Nov. 2015.
  6. W. C. Lih, J. H. Yen, F. H. Shieh, and Y. M. Liao, "Second use of retired lithium-ion battery packs from electric vehicles: Technological challenges, cost analysis and optimal business model," 2012 International Symposium on Computer, Consumer and Control, pp. 381-384. Jun. 2012.
  7. I. Semanjski and S. Gautama, "Forecasting the state of health of electric vehicle batteries to evaluate the viability of car sharing practices," Energies 2016, Vol. 9, No. 12, Sep. 2016.
  8. S. S. Choi and H. S. Lim, “Factors that affect cycle-life and possible degradation mechanisms of a Li-ion cell based on $LiCoO_2$,” Journal of Power Sources, Vol. 111, No. 1, pp. 130-136, May 2002. https://doi.org/10.1016/S0378-7753(02)00305-1
  9. The KEEA, "2018 kia soul EV gets 30 kWh battery, range boost," Retrieved Mar. 25, 2017, from https://www.thekeea.com.
  10. Spirit Energy, "Battery storage knowledge bank," Retrieved 15, Aug. 2018, form https://www.spiritenergy.co.uk/kb-batteries?understanding-batteries.
  11. J. Belt, V. Utgikar, and I. Bloom, "Calendar and PHEV cycle life aging of high-energy, lithium-ion cells containing blended spinel and layered-oxide cathodes," Journal of Power Sources, No. 23, Vol. 196, pp. 10213-10221, Dec. 2011. https://doi.org/10.1016/j.jpowsour.2011.08.067
  12. G. Plett, "Battery management systems, volume II: Equivalent-circuit methods: 2," Artech House, 2015.