Nonlinear Adaptive Observer for a Lithium-Ion Battery Cell Based on Coupled Electrochemical–Thermal Model

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
S. Dey ◽  
B. Ayalew ◽  
P. Pisu
Keyword(s):  
Thermal Model ◽  
Adaptive Observer ◽  
Parameter Estimates ◽  
Physical Parameters ◽  
Model Parameters ◽  
Battery Cell ◽  
Thermal Dynamics ◽  
Adaptive Scheme ◽  
Li Ion ◽  
Battery Cells

Real-time estimation of battery internal states and physical parameters is of the utmost importance for intelligent battery management systems (BMS). Electrochemical models, derived from the principles of electrochemistry, are arguably more accurate in capturing the physical mechanism of the battery cells than their counterpart data-driven or equivalent circuit models (ECM). Moreover, the electrochemical phenomena inside the battery cells are coupled with the thermal dynamics of the cells. Therefore, consideration of the coupling between electrochemical and thermal dynamics inside the battery cell can be potentially advantageous for improving the accuracy of the estimation. In this paper, a nonlinear adaptive observer scheme is developed based on a coupled electrochemical–thermal model of a Li-ion battery cell. The proposed adaptive observer scheme estimates the distributed Li-ion concentration and temperature states inside the electrode, and some of the electrochemical model parameters, simultaneously. These states and parameters determine the state of charge (SOC) and state of health (SOH) of the battery cell. The adaptive scheme is split into two separate but coupled observers, which simplifies the design and gain tuning procedures. The design relies on a Lyapunov's stability analysis of the observers, which guarantees the convergence of the combined state-parameter estimates. To validate the effectiveness of the scheme, both simulation and experimental studies are performed. The results show that the adaptive scheme is able to estimate the desired variables with reasonable accuracy. Finally, some scenarios are described where the performance of the scheme degrades.

Adaptive Observer Design for a Li-Ion Cell Based on Coupled Electrochemical-Thermal Model

2014 ◽  
Author(s):  
Satadru Dey ◽  
Beshah Ayalew ◽  
Pierluigi Pisu
Keyword(s):  
Thermal Model ◽  
Design Procedure ◽  
State Parameter ◽  
Observer Design ◽  
Adaptive Observer ◽  
Accurate Estimation ◽  
Parameter Estimates ◽  
Physical Parameters ◽  
Thermal Dynamics ◽  
Li Ion

Accurate real-time knowledge of battery internal states and physical parameters is of the utmost importance for intelligent battery management. Electrochemical models are arguably more accurate in capturing physical phenomena inside the cells compared to their data-driven or equivalent circuit based counterparts. Moreover, consideration of the coupling between electrochemical and thermal dynamics can be potentially beneficial for accurate estimation. In this paper, a nonlinear adaptive observer design is presented based on a coupled electrochemical-thermal model for a Li-ion cell. The proposed adaptive observer estimates distributed Li-ion concentrations, lumped temperature and some electrochemical parameters simultaneously. The observer design is split into two separate parts to simplify the design procedure and gain tuning. These separate parts are designed based on Lyapunov’s stability analysis guaranteeing the convergence of the combined state-parameter estimates. Simulation studies are provided to demonstrate the effectiveness of the scheme.

Real-Time Estimation of Lithium-Ion Concentration in Both Electrodes of a Lithium-Ion Battery Cell Utilizing Electrochemical–Thermal Coupling

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Satadru Dey ◽  
Beshah Ayalew
Keyword(s):  
Real Time ◽  
Unscented Kalman Filter ◽  
Lithium Ion ◽  
Time Estimation ◽  
Li Ion Battery ◽  
Battery Cell ◽  
Thermal Dynamics ◽  
Estimation Scheme ◽  
Real Time Estimation ◽  
Li Ion

This paper proposes and demonstrates an estimation scheme for Li-ion concentrations in both electrodes of a Li-ion battery cell. The well-known observability deficiencies in the two-electrode electrochemical models of Li-ion battery cells are first overcome by extending them with a thermal evolution model. Essentially, coupling of electrochemical–thermal dynamics emerging from the fact that the lithium concentrations contribute to the entropic heat generation is utilized to overcome the observability issue. Then, an estimation scheme comprised of a cascade of a sliding-mode observer and an unscented Kalman filter (UKF) is constructed that exploits the resulting structure of the coupled model. The approach gives new real-time estimation capabilities for two often-sought pieces of information about a battery cell: (1) estimation of cell-capacity and (2) tracking the capacity loss due to degradation mechanisms such as lithium plating. These capabilities are possible since the two-electrode model needs not be reduced further to a single-electrode model by adding Li conservation assumptions, which do not hold with long-term operation. Simulation studies are included for the validation of the proposed scheme. Effect of measurement noise and parametric uncertainties is also included in the simulation results to evaluate the performance of the proposed scheme.

Thermal Analysis of Li-ion Battery

2013 ◽  
Vol 401-403 ◽  
pp. 450-455
Author(s):  
Gaoussou Hadia Fofana ◽  
You Tong Zhang
Keyword(s):  
Thermal Behavior ◽  
Thermal Model ◽  
Air Cooling ◽  
Li Ion Battery ◽  
Battery System ◽  
Cooling Conditions ◽  
3D Fea ◽  
Li Ion ◽  
Prismatic Cell ◽  
Battery Cells

Abstract. The paper has built 3D-FEA models to simulate the electro-thermal behavior of Li-ion battery cells with Pouch Cell and Prismatic Cell by ANSYS. As for two models, the Li-ion battery system is simplified as a single equivalent battery layer (Pouch Cell) or multiple equivalent battery layers (Prismatic Cell) with the equivalent electrodes and separator. They were simulated under air cooling conditions. Simulations were compared with available battery temperature measurements. This shows that the 3D electro-thermal model applied in this study characterizes the electro-thermal behavior of the Li-ion battery cells reasonably well.

Estimation of Cumene Cracking Reaction-Diffusion Model Parameters: Uniqueness and Parametric Sensitivity Analysis

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Peter Schwan ◽  
Klaus P Möller
Keyword(s):  
Sensitivity Analysis ◽  
Steady State ◽  
Parameter Estimates ◽  
Physical Parameters ◽  
Model Parameters ◽  
Response Curves ◽  
Cumene Cracking ◽  
Irreversible Reaction ◽  
Reaction Diffusion Model ◽  
Order Of Magnitude

The pulse response of cumene cracking over ZSM5 extrudates has been measured using a Jetloop recycle reactor. A model assuming first order irreversible reaction with constant macro-pore diffusivity and linear adsorption was used to describe the response curves of the reactants and products. The model parameters adsorption, diffusion and reaction rate are in general highly correlated. Relationships for regions of parameter insensitivity and correlation functions between dependent parameters are given. With the aid of independent measurement of adsorption, a sensitivity analysis and a similarity analysis between equations, it was possible to reduce the 7 parameter model into a 2 parameter model for conditions of strong diffusion limitation observed in these experiments. Although good model fits could be achieved, a high degree of uncertainty in the parameter estimates remained, which reflects the high correlation of the physical parameters. Comparison with steady state results shows that the transient diffusivity for cumene is approximately equal to the Knudsen diffusivity, but an order of magnitude lower than the steady state diffusivity. The transient Thiele modulus for cumene was an order of magnitude higher than the steady state value.

A Reduced-Order Model for the Thermal Dynamics of Li-Ion Battery Cells

2010 ◽  
Vol 43 (7) ◽  
pp. 192-197 ◽  
Author(s):  
Matteo Muratori ◽  
Marcello Canova ◽  
Yann Guezennec ◽  
Giorgio Rizzoni
Keyword(s):  
Reduced Order Model ◽  
Li Ion Battery ◽  
Order Model ◽  
Thermal Dynamics ◽  
Reduced Order ◽  
Li Ion ◽  
Battery Cells

A Model Order Reduction Method for the Temperature Estimation in a Cylindrical Li-Ion Battery Cell

2010 ◽  
Author(s):  
Matteo Muratori ◽  
Ning Ma ◽  
Marcello Canova ◽  
Yann Guezennec
Keyword(s):  
Model Order Reduction ◽  
Dynamic Models ◽  
Reduction Method ◽  
Order Reduction ◽  
Li Ion Battery ◽  
Battery Cell ◽  
Thermal Dynamics ◽  
Model Order ◽  
Li Ion ◽  
Order Reduction Method

The thermal characterization of Li-ion batteries for EVs, HEVs and PHEVs is a topic of great relevance, especially for the evaluation of the battery pack state of health (SoH) during vehicle operations and for battery life estimation. This work proposes a reduced-order model that estimates the thermal dynamics of a cylindrical Li-ion battery cell, with respect to time-varying current demands. Unlike most “black-box” dynamic models, based on system identification techniques, the proposed approach relies on the definition of a boundary-value problem for heat conduction, in the form of a linear partial differential equation. The problem is then converted into a low-order linear model by applying model-order reduction method in the frequency domain. The resulting model predicts the temperature dynamics at the center and at the external surface in relation with the rate of heat generation and the coolant temperature. In this paper, the model is applied to estimate the internal temperature of a cylindrical cell during a discharging transient. The model uses electrical data acquired from experimental tests and is validated by comparison with experimental data and 3D FEM thermal simulation.

scholarly journals Effect of parameters on thermal and fluid flow behavior of battery thermal management system

2020 ◽  
pp. 290-290
Author(s):  
Asif Afzal ◽  
Awatef Abidi ◽  
Ad Samee ◽  
Rk Razak ◽  
Manzoore Soudagar ◽  
...  
Keyword(s):  
Nusselt Number ◽  
Fluid Flow ◽  
Friction Coefficient ◽  
Thermal Management ◽  
Lateral Surface ◽  
Maximum Temperature ◽  
Battery Cell ◽  
Battery Thermal Management ◽  
Li Ion ◽  
Battery Cells

In modern electric vehicles the thermal stability problems associated with Lithium-ion (Li-ion) battery system is of major concern. Proper battery thermal management systems (BTMS) is required to ensure safety and efficient performance of battery cells. A realistic conjugate heat transfer and fluid flow analysis of Li-ion prismatic battery cell is performed. The flow of air as coolant, is laminar, flowing between the heat generating battery cells. The effect of few important working parameters like volumetric heat generation ( q), conduction-convection parameter (?cc), Reynolds number (Re), Aspect ratio (Ar), and spacing between the cells ( f) is investigated in this work. For the wide range of parameters considered, the temperature variations in battery cell and coolant is carried out. Focusing mainly on effect of Re and f, behavior of local Nusselt number (Nux), local friction coefficient (Cf, x), average Nusselt number (Nuavg), average friction coefficient (Cf, avg), maximum temperature, mean fluid temperature, heat removed from the lateral surface of cell are discussed. Nuavg increased with increase in Re but decreased with increase in f, whereas Cf, avg decreased with increase in Re and f. It is also found that their exists an upper and lower limit on Re and f above and below which the change in Cf, avg and Nuavg is negligible. Maximum temperature is significantly influenced at low Re and for all f. From the lateral surface of battery over which the coolant flows, more than 96% of heat generated in cell is removed.

scholarly journals New Experimental Approach for the Determination of the Heat Generation in a Li-Ion Battery Cell

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6972
Author(s):  
Rouven Christen ◽  
Björn Martin ◽  
Gerhard Rizzo
Keyword(s):  
Heat Generation ◽  
Experimental Approach ◽  
Equivalent Circuit Model ◽  
Lithium Titanate ◽  
Model Parameters ◽  
Battery Cell ◽  
Flow Measurements ◽  
Additional Information ◽  
Generation Mechanisms ◽  
Battery Cells

With regard to safety, efficiency and lifetime of battery systems, the thermal behavior of battery cells is of great interest. The use of models describing the thermoelectric behavior of battery cells improves the understanding of heat generation mechanisms and enables the development of optimized thermal management systems. In this work, a novel experimental approach is presented to determine both the irreversible heat due to ohmic losses and the reversible heat due to entropy changes directly via heat flow measurements. No additional information about thermal properties of the battery cell, such as heat capacity or thermal conductivity, are required. Thus, the exothermic and endothermic nature of reversible heat generated in a complete charge/discharge cycle can be investigated. Moreover, the results of the proposed method can potentially be used to provide an additional constraint during the identification process of the equivalent circuit model parameters. The described method is applied to a 23Ah lithium titanate cell and the corresponding results are presented.

scholarly journals Thermal Model Parameter Identification of a Lithium Battery

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Dirk Nissing ◽  
Arindam Mahanta ◽  
Stefan van Sterkenburg
Keyword(s):  
Thermal Model ◽  
Lithium Battery ◽  
Least Square ◽  
Model Parameters ◽  
Battery Management ◽  
Single Measurement ◽  
Cell Temperature ◽  
Battery Cell ◽  
Battery Management Systems ◽  
Method Of Least Square

The temperature of a Lithium battery cell is important for its performance, efficiency, safety, and capacity and is influenced by the environmental temperature and by the charging and discharging process itself. Battery Management Systems (BMS) take into account this effect. As the temperature at the battery cell is difficult to measure, often the temperature is measured on or nearby the poles of the cell, although the accuracy of predicting the cell temperature with those quantities is limited. Therefore a thermal model of the battery is used in order to calculate and estimate the cell temperature. This paper uses a simple RC-network representation for the thermal model and shows how the thermal parameters are identified using input/output measurements only, where the load current of the battery represents the input while the temperatures at the poles represent the outputs of the measurement. With a single measurement the eight model parameters (thermal resistances, electric contact resistances, and heat capacities) can be determined using the method of least-square. Experimental results show that the simple model with the identified parameters fits very accurately to the measurements.

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