Comparative study for generic battery models used for electric vehicles

Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are the most appropriate and feasible solutions. In this article, three different battery modeling approaches are considered, and their parameters’ identification are described. Two of the chosen models require no laboratory tests for parametrization, and most of the information are derived from the manufacturer’s datasheet, while the last battery model requires some laboratory assessments. The models are then validated at steady state, comparing the simulation results with the datasheet discharge curves, and in transient operation, comparing the simulation results with experimental results. The three modeling and parametrization approaches are systematically applied to the LG 18650HG2 lithium-ion cell, and results are presented, compared and discussed.

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“…One of the best-known mathematical models for constant-current discharge is the Shepherd model [30,31]:…”

Section: Shepherd Modelmentioning

confidence: 99%

Battery Models for Battery Powered Applications: A Comparative Study

et al. 2020

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“…Several battery equivalent circuit models can be found in [29]- [31], [34], [40]. The general conclusion is, that the Randles model, as shown in Fig.…”

Section: A Dynamic Battery Modelingmentioning

confidence: 99%

Battery Modeling and Parameter Extraction for Drive Cycle Loss Evaluation of a Modular Battery System for Vehicles Based on a Cascaded H-Bridge Multilevel Inverter

Theliander

Kersten

Kuder

et al. 2020

IEEE Trans. on Ind. Applicat.

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This article deals with the modeling and the parameterization of the battery packs used in cascaded H-bridge multilevel propulsion inverters. Since the battery packs are intermittently conducting the motor currents, the battery cells are stressed with a dynamic current containing a substantial amount of low-order harmonic components up to a couple of kHz, which is a major difference in comparison to a traditional two-level inverter drive. Different models, such as pure resistive and dynamic RC-networks, are considered to model the energy losses for different operating points (OPs) and driving cycles. Using a small-scale setup, the models' parameters are extracted using both a low-frequency, pulsed current, and an electrochemical impedance spectroscopy (EIS) sweep. The models are compared against measurements conducted on the small-scale setup at different OPs. Additionally, a drive cycle loss comparison is simulated. The simple resistive model overestimates the losses by about 20% and is, thus, not suitable. The dynamic three-time-constant model, parameterized by a pulsed current, complies with the measurements for all analyzed OPs, especially at low speed, with a maximum deviation of 3.8%. Extracting the parameters using an EIS seems suitable for higher speeds, though the losses for the chosen OPs are underestimated by 1.5%-7.9%.

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“…To get the same operating points for the small scale system, the operating points in TABLE II are down-scaled according to ( 13) and (15) and are shown in Table III. In this way, each single cell is stressed with the same current as in the example hybrid vehicle.…”

Section: Small Scale System and Model Verificationmentioning

confidence: 99%

LiFeP0₄Battery Modeling and Drive Cycle Loss Evaluation in Cascaded H-Bridge Inverters for Vehicles

Theliander

Kersten

Kuder

et al. 2019

2019 IEEE Transportation Electrification Conference and Expo (ITEC)

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This paper deals with the modeling and parameterization of LiFePO4 batteries when used in cascaded H-bridge multilevel inverter drive systems. Since the battery packs are intermittently conducting the motor currents, the battery cells are stressed with a dynamic current waveform containing a substantial amount of low order harmonic components in the range of a couple of kHz. Different battery models like a pure resistive or different RC networks are considered, to determine the battery losses. Measurements of the voltage drop for a pulsed current of variable frequency and magnitude are done to be able to determine the model parameters. The models are then verified against measurements on a battery pack placed in a small scale multilevel inverter operated at 6 different operating point that are representative for the operation of an electrified vehicle. It is shown that the dynamic model agrees very well with the measurements for all operating points analyzed with a maximum deviation of 4 %. The results are also compared with the commonly used resistive model which overestimates the losses with typically around 20 % for the evaluated points. Simulations of 4 full drive cycles are performed where it is stated that the resistive model always shows about 20 % more losses compared to the 3 time constant model.

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Comparative study for generic battery models used for electric vehicles

Cited by 19 publications

References 12 publications

Battery Models for Battery Powered Applications: A Comparative Study

Battery Models for Battery Powered Applications: A Comparative Study

Battery Modeling and Parameter Extraction for Drive Cycle Loss Evaluation of a Modular Battery System for Vehicles Based on a Cascaded H-Bridge Multilevel Inverter

LiFeP0₄Battery Modeling and Drive Cycle Loss Evaluation in Cascaded H-Bridge Inverters for Vehicles

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Comparative study for generic battery models used for electric vehicles

Cited by 19 publications

References 12 publications

Battery Models for Battery Powered Applications: A Comparative Study

Battery Models for Battery Powered Applications: A Comparative Study

Battery Modeling and Parameter Extraction for Drive Cycle Loss Evaluation of a Modular Battery System for Vehicles Based on a Cascaded H-Bridge Multilevel Inverter

LiFeP04Battery Modeling and Drive Cycle Loss Evaluation in Cascaded H-Bridge Inverters for Vehicles

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LiFeP0₄Battery Modeling and Drive Cycle Loss Evaluation in Cascaded H-Bridge Inverters for Vehicles