Online battery aging calculation in plug-in hybrid electric vehicle considering driving condition

ABSTRACT

Online calculation of battery capacity loss and its instantaneous remaining life for electric and hybrid electric vehicles is a challenging subject, particularly for designing and optimizing vehicle energy management in real-life driving conditions. This paper presents an online method for estimating plug-in hybrid electric vehicle battery degradation, considering the driving conditions. For this purpose, a national parallel plug-in hybrid electric vehicle is employed, where its components have been sized based on some experimental map characteristics using a genetic algorithm. Also, a real-world driving cycle is developed based on the data gathered in the actual traffic conditions in Tehran. The vehicle’s energy management system is designed using an adaptive equivalent consumption minimization strategy. In addition, an empirical battery life model combined with an online cycle counting method is used for battery aging calculation. To evaluate the effectiveness of the proposed approach, the capacity fade of the vehicle battery over various driving cycles has been calculated. The comparison of the results confirms the efficacy of the proposed algorithm compared to the Rainflow counting algorithm. Applying the Rainflow to all driving cycles yields consistent outcomes. However, when employing the suggested method, capacity losses of approximately 2.4%, 1.9%, 2.1%, and 1.4% are detected in Tehran, FTP-75, WLTP, and NEDC, respectively, following one hundred driving cycles. This means the capacity loss increases by 35%, 50%, and 71% for FTP-75, WLTP, and Tehran, respectively, compared with the NEDC driving cycle.

KEYWORDS:

• Plug-in hybrid electric vehicle (PHEV)
• battery cycle counting method
• battery aging
• component sizing optimization
• energy management system

Nomenclature

Table

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Morteza Montazeri-Gh

Morteza Montazeri-Gh is a professor of mechanical engineering at IUST, Tehran, Iran. He established the Systems Simulation and Control Laboratory in 1996. One of the current research activities in this laboratory is designing and implementing control algorithms for HEVs and PHEVs.

Ehsan Alimohammadi

Ehsan Alimohammadi is a Mechanical Engineering PhD student at the Iran University of Science and Technology (IUST), Tehran, Iran. One of his research interests is estimating battery life during PHEV operation.