On-Board State-of-Health Estimation at a Wide Ambient Temperature Range in Lithium-Ion Batteries

Energies

Tiansi Wang²  Lei Pei¹  Tingting Wang²  Rengui Lu²  Chunbo Zhu¹ 

[1] School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China;

关键词: lithium-ion batteries;    state-of-health (SOH);    wide temperature range;    resistance increase;    capacity loss;   

DOI  :  10.3390/en8088467

来源: mdpi

【 摘 要 】

A state-of-health (SOH) estimation method for electric vehicles (EVs) is presented with three main advantages: (1) it provides joint estimation of cell’s aging states in terms of power and energy (i.e., SOH_P and SOH_E)—because the determination of SOH_P and SOH_E can be reduced to the estimation of the ohmic resistance increase and capacity loss, respectively, the ohmic resistance at nominal temperature will be taken as a health indicator, and the capacity loss is estimated based on a mechanistic model that is developed to describe the correlation between resistance increase and capacity loss; (2) it has wide applicability to various ambient temperatures—to eliminate the effects of temperature on the resistance, another mechanistic model about the resistance against temperature is presented, which can normalize the resistance at various temperatures to its standard value at the nominal temperature; and (3) it needs low computational efforts for on-board application—based on a linear equation of cell’s dynamic behaviors, the recursive least-squares (RLS) algorithm is used for the resistance estimation. Based on the designed performance and validation experiments, respectively, the coefficients of the models are determined and the accuracy of the proposed method is verified. The results at different aging states and temperatures show good accuracy and reliability.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.