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Fractional order modeling based optimal multistage constant current charging strategy for lithium iron phosphate batteries

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K. Dhananjay Rao
K. Dhananjay Rao
K. Dhananjay Rao
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Anilkumar Chappa at Sri Vasavi Engineering College
Anilkumar Chappa
SVNSK Chaitanya
SVNSK Chaitanya
SVNSK Chaitanya
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A. Hemachander
A. Hemachander
A. Hemachander
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Abstract and Figures

The primary power source for electric vehicles (EVs) is batteries. Due to the superior characteristics like higher energy density, power density, and life cycle of the lithium iron phosphate (LFP) battery is most frequently chosen among the various types of lithium‐ion batteries (LIBs). The main issues that users encounter are the time required to charge an EV battery and the safety of the EV battery during the charging period. The fast‐charging means, charging a battery with high currents which may lead to a rise in the temperature of a battery. The abrupt rise in battery temperature may cause changes in the internal chemical structures of the battery, reducing battery life even further. In this regard, an optimal charging profile design is of utmost importance in order to satisfy dual objectives simultaneously such as less charging time and improvement in life of the battery. To overcome the conflict between charging speed and rise in temperature an optimal multistage constant current (MSCC) based charging strategy has been investigated under different operating conditions. In addition, the proposed charging profiles have been studied using experimentation.
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RESEARCH ARTICLE
Fractional order modeling based optimal multistage
constant current charging strategy for lithium iron
phosphate batteries
K. Dhananjay Rao
1
| Anilkumar Chappa
2
| SVNSK Chaitanya
1
|
A. Hemachander
3
| B. Phani Teja
4
| Subhojit Dawn
1
| Miska Prasad
5
|
Taha Selim Ustun
6
1
Department of Electrical & Electronics
Engineering, Velagapudi Ramakrishna
Siddhartha Engineering College,
Vijayawada, India
2
Department of Electrical & Electronics
Engineering, Sri Vasavi Engineering
College, Tadepalligudem, India
3
Department of Electrical and Electronics
Engineering, National Institute of
Technology Puducherry, Karaikal, India
4
Department of Electrical and Electronics
Engineering, SRM Institute of Science and
Technology Chennai, Kattankulathur,
India
5
Department of Electrical & Electronics
Engineering, ACE Engineering College,
Hyderabad, India
6
Fukushima Renewable Energy Institute,
AIST (FREA), Koriyama, Japan
Correspondence
K. Dhananjay Rao, Department of
Electrical & Electronics Engineering,
Velagapudi Ramakrishna Siddhartha
Engineering College, Vijayawada, India.
Email: kdhananjayrao@vrsiddhartha.ac.
in;kdhananjayrao@gmail.com
Taha Selim Ustun, Fukushima Renewable
Energy Institute, AIST (FREA), Koriyama,
Japan.
Email: selim.ustun@aist.go.jp
Abstract
The primary power source for electric vehicles (EVs) is batteries. Due to the
superior characteristics like higher energy density, power density, and life
cycle of the lithium iron phosphate (LFP) battery is most frequently chosen
among the various types of lithium-ion batteries (LIBs). The main issues that
users encounter are the time required to charge an EV battery and the safety
of the EV battery during the charging period. The fast-charging means, charg-
ing a battery with high currents which may lead to a rise in the temperature of
a battery. The abrupt rise in battery temperature may cause changes in the
internal chemical structures of the battery, reducing battery life even further.
In this regard, an optimal charging profile design is of utmost importance in
order to satisfy dual objectives simultaneously such as less charging time and
improvement in life of the battery. To overcome the conflict between charging
speed and rise in temperature an optimal multistage constant current (MSCC)
based charging strategy has been investigated under different operating condi-
tions. In addition, the proposed charging profiles have been studied using
experimentation.
KEYWORDS
fractional order battery modeling, lithium iron phosphate battery, multistage constant
current charging, state of charge, thermal modeling
1|INTRODUCTION
Electric vehicle (EV) popularity is highly increasing, with
the goal of reducing automobile emissions through
energy efficiency and environmental preservation.
1
With
the rapid advancement of EVs, the demand for lithium
batteries has been increased in recent years. Battery tech-
nology has become an integral part of human lives with
wide range of applications.
2
There are different battery
chemistries are commercially available.
3
Among them,
LFP batteries are widely preferred owing to their superior
performance.
4
These batteries have a long cycle life, high
Received: 8 June 2023 Revised: 29 December 2023 Accepted: 29 January 2024
DOI: 10.1002/est2.593
Energy Storage. 2024;6:e593. wileyonlinelibrary.com/journal/est2 © 2024 John Wiley & Sons Ltd. 1of14
https://doi.org/10.1002/est2.593
... Moreover, it also provides temperature control and performs cell balancing across the cells [3], [4]. Among these factors, the State of Health (SOH) is the primary parameter defining battery degradation and influencing its performance. ...
... The candidate's hidden state, as derived from equation (4), is employed for computing the present hidden state Ht. The advantage of Gated Recurrent Unit (GRU) over Long Short-Term Memory (LSTM) lies in the utilization of a singular gate, specifically the update gate, which controls the information flow from both the previous hidden state and the candidate hidden state. ...
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