Parametric study of limiting cell design variables in a lithium battery pack

Author(s):  
Corina Eva Aimo ◽  
Ignacio Schmidhalter ◽  
Pio Antonio Aguirre
Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1448
Author(s):  
Nam-Gyu Lim ◽  
Jae-Yeol Kim ◽  
Seongjun Lee

Battery applications, such as electric vehicles, electric propulsion ships, and energy storage systems, are developing rapidly, and battery management issues are gaining attention. In this application field, a battery system with a high capacity and high power in which numerous battery cells are connected in series and parallel is used. Therefore, research on a battery management system (BMS) to which various algorithms are applied for efficient use and safe operation of batteries is being conducted. In general, maintenance/replacement of multi-series/multiple parallel battery systems is only possible when there is no load current, or the entire system is shut down. However, if the circulating current generated by the voltage difference between the newly added battery and the existing battery pack is less than the allowable current of the system, the new battery can be connected while the system is running, which is called hot swapping. The circulating current generated during the hot-swap operation is determined by the battery’s state of charge (SOC), the parallel configuration of the battery system, temperature, aging, operating point, and differences in the load current. Therefore, since there is a limit to formulating a circulating current that changes in size according to these various conditions, this paper presents a circulating current estimation method, using an artificial neural network (ANN). The ANN model for estimating the hot-swap circulating current is designed for a 1S4P lithium battery pack system, consisting of one series and four parallel cells. The circulating current of the ANN model proposed in this paper is experimentally verified to be able to estimate the actual value within a 6% error range.


2004 ◽  
Vol 261-263 ◽  
pp. 663-668 ◽  
Author(s):  
Kwang Joon Yoon ◽  
Young Suk Kim ◽  
Young Bae Kim ◽  
J.D. Lee ◽  
Hyun Chul Park ◽  
...  

In this paper, a simple conformal load-bearing antenna structure smart skin with a multi-layer sandwich structure composed of carbon/epoxy, glass/epoxy, and a dielectric polymer was designed and fabricated. The mechanical properties of each material in the designed smart skin were obtained from experiments. Tests and analyses were conducted to study the behavior of the smart skin under compressive loads. The designed smart skin failed due to buckling before compression failure. The stresses of each layer and the first failed layer of the smart skin were predicted using MSC/NASTRAN. The finite element model was verified by comparing the numerical results from geometrical linear/nonlinear analyses with the measured data. The numerically predicted structural behavior of the smart skin agreed well with the experimental data. The results showed that the carbon/epoxy layer took charge of most of the compressive load, and the first failure occurred in the dielectric layer while the other layers remained safe. A numerical model was used to obtain design data from the parametric study. The effect of changing the design variables on the buckling and compressive behavior of the smart skin was also investigated. As a result, it was confirmed that the transverse shear moduli of the honeycomb core had a serious impact on the buckling load of the smart skin when the shear deformation was considerable.


Author(s):  
Mayank Lal ◽  
Feng Wang ◽  
Xiaohua Lu ◽  
Abhilash Sebastian

Abstract Steel Lazy wave risers are being increasingly used for deep water applications due to better strength and fatigue performance in the touchdown zone compared to steel catenary risers. Several parameters govern the design of steel lazy wave risers including the length of the catenary from hang-off to start of buoyancy section and the length of the buoyancy section. In this paper, a parametric study is performed to investigate the trends in strength and fatigue performance of steel lazy wave risers with change in configuration parameters. A normative cost assessment is also performed to show the impact of these design variables on overall cost of the system. Dynamic analysis is performed to check the change in strength and fatigue performance of steel lazy wave risers as the configuration parameters are changed. The results from the parametric study will assist in designing steel lazy wave risers which satisfy the strength and fatigue design criteria.


Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 321 ◽  
Author(s):  
Sorour Alotaibi ◽  
Osama Ibrahim ◽  
Yu Wang ◽  
Tengfei Luo

This paper presents an exergy analysis to evaluate the performance of a continuous directional solvent extraction (DSE) desalination process using octanoic acid. The flow of exergy was calculated for each thermodynamic state and balanced for different components of the system to quantify the inefficiencies in the process. A parametric study was performed to evaluate the impact of three critical design variables on exergy consumption. The parametric study reveals that the total exergy input decreases significantly with an increase in heat exchanger effectiveness. The results also indicate that the heat exchangers account for the highest exergy destruction. The total exergy consumption, however, has a slightly declining trend as the recovery-ratio increases. There is a small variation in the total exergy consumption, within the uncertainty of the calculation, as the highest process temperature increases. When compared to conventional desalination processes, the exergy consumption of the DSE, with heat recovery of 90%, is comparable to those of multi-stage flashing (MSF), but much higher than reverse osmosis (RO). Octanoic acid, which has low product water yield, is identified as the primary factor negatively impacting the exergy consumptions. To exploit the low-grade and low-temperature heat source feature of the DSE process, directional solvents with higher yield should be identified or designed to enable its full implementation.


2021 ◽  
Vol 2083 (2) ◽  
pp. 022071
Author(s):  
Qingyuan Fang

Abstract Aiming at the uneven heat generation in various parts of the electric vehicle lithium battery pack during the discharge process, the heat generation mechanism is studied, and the lithium battery catalytic performance model is established to obtain the current density and heat generation rate distribution law of the lithium battery cell on the cell. The thermal model can simulate the thermal behavior of the battery under application conditions. Study the laws of battery heat production, heat transfer, and heat dissipation, and calculate the temperature changes inside and on the battery and the temperature field information in real time to provide a basis for the design and optimization of the battery and battery pack thermal management system. The simulation results show that the established model can predict the heating distribution and temperature field of the internal layered structure of the lithium-ion battery, which is helpful for the subsequent analysis of key influencing factors.


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