The Experts below are selected from a list of 3948 Experts worldwide ranked by ideXlab platform
Xi Zhang - One of the best experts on this subject based on the ideXlab platform.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 1 lithium concentration estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract To guarantee the safety, high efficiency and long lifetime for lithium-ion battery, an advanced battery management system requires a physics-meaningful yet computationally efficient battery model. The pseudo-two dimensional (P2D) electrochemical model can provide physical information about the lithium concentration and potential distributions across the cell dimension. However, the extensive computation burden caused by the temporal and spatial discretization limits its real-time application. In this research, we propose a new simplified electrochemical model (SEM) by modifying the boundary conditions for electrolyte diffusion equations, which significantly facilitates the analytical solving process. Then to obtain a reduced order transfer function, the Pade Approximation method is adopted to simplify the derived transcendental impedance solution. The proposed model with the reduced order transfer function can be briefly computable and preserve physical meanings through the presence of parameters such as the solid/electrolyte diffusion coefficients (Ds&De) and particle radius. The simulation illustrates that the proposed simplified model maintains high accuracy for electrolyte phase concentration (Ce) predictions, saying 0.8% and 0.24% modeling error respectively, when compared to the rigorous model under 1C-rate pulse charge/discharge and urban dynamometer driving schedule (UDDS) profiles. Meanwhile, this simplified model yields significantly reduced computational burden, which benefits its real-time application.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 2 modeling and parameter estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract The electrochemistry-based battery model can provide physics-meaningful knowledge about the lithium-ion battery system with extensive computation burdens. To motivate the development of reduced order battery model, three major contributions have been made throughout this paper: (1) the transfer function type of simplified electrochemical model is proposed to address the current-voltage relationship with Pade Approximation method and modified boundary conditions for electrolyte diffusion equations. The model performance has been verified under pulse charge/discharge and dynamic stress test (DST) profiles with the standard derivation less than 0.021 V and the runtime 50 times faster. (2) the parametric relationship between the equivalent circuit model and simplified electrochemical model has been established, which will enhance the comprehension level of two models with more in-depth physical significance and provide new methods for electrochemical model parameter estimation. (3) four simplified electrochemical model parameters: equivalent resistance R eq , effective diffusion coefficient in electrolyte phase D e eff , electrolyte phase volume fraction e and open circuit voltage (OCV), have been identified by the recursive least square (RLS) algorithm with the modified DST profiles under 45, 25 and 0 °C. The simulation results indicate that the proposed model coupled with RLS algorithm can achieve high accuracy for electrochemical parameter identification in dynamic scenarios.
A Yan - One of the best experts on this subject based on the ideXlab platform.
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Pade Approximation for stochastic discrete event systems
IEEE Transactions on Automatic Control, 1995Co-Authors: Weibo Gong, S Nananukul, A YanAbstract:We show that Pade Approximation can be effectively used for Approximation of performance functions in discrete-event systems. The method is (1) obtaining the MacLaurin coefficients of the performance function and (2) finding a Pade approximant from the MacLaurin coefficients and use it to approximate the function. We use the method with the expected number of renewals in a random interval, GI/G/1 systems, and inventory systems. The results are very good. >
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Pade Approximation for stochastic discrete event systems
Conference on Decision and Control, 1992Co-Authors: Weibo Gong, S Nananukul, A YanAbstract:It is shown that Pade Approximation can be used effectively for the Approximation of performance functions in discrete event systems. The steps of the method are: (1) obtain the MacLaurin coefficients of the performance function, and (2) find a Pade approximant from the MacLaurin coefficients and use it to approximate the function. The method is used with GI/G/1/1 systems, GI/G/1 systems, and inventory systems. The results are satisfactory. >
Shifei Yuan - One of the best experts on this subject based on the ideXlab platform.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 1 lithium concentration estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract To guarantee the safety, high efficiency and long lifetime for lithium-ion battery, an advanced battery management system requires a physics-meaningful yet computationally efficient battery model. The pseudo-two dimensional (P2D) electrochemical model can provide physical information about the lithium concentration and potential distributions across the cell dimension. However, the extensive computation burden caused by the temporal and spatial discretization limits its real-time application. In this research, we propose a new simplified electrochemical model (SEM) by modifying the boundary conditions for electrolyte diffusion equations, which significantly facilitates the analytical solving process. Then to obtain a reduced order transfer function, the Pade Approximation method is adopted to simplify the derived transcendental impedance solution. The proposed model with the reduced order transfer function can be briefly computable and preserve physical meanings through the presence of parameters such as the solid/electrolyte diffusion coefficients (Ds&De) and particle radius. The simulation illustrates that the proposed simplified model maintains high accuracy for electrolyte phase concentration (Ce) predictions, saying 0.8% and 0.24% modeling error respectively, when compared to the rigorous model under 1C-rate pulse charge/discharge and urban dynamometer driving schedule (UDDS) profiles. Meanwhile, this simplified model yields significantly reduced computational burden, which benefits its real-time application.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 2 modeling and parameter estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract The electrochemistry-based battery model can provide physics-meaningful knowledge about the lithium-ion battery system with extensive computation burdens. To motivate the development of reduced order battery model, three major contributions have been made throughout this paper: (1) the transfer function type of simplified electrochemical model is proposed to address the current-voltage relationship with Pade Approximation method and modified boundary conditions for electrolyte diffusion equations. The model performance has been verified under pulse charge/discharge and dynamic stress test (DST) profiles with the standard derivation less than 0.021 V and the runtime 50 times faster. (2) the parametric relationship between the equivalent circuit model and simplified electrochemical model has been established, which will enhance the comprehension level of two models with more in-depth physical significance and provide new methods for electrochemical model parameter estimation. (3) four simplified electrochemical model parameters: equivalent resistance R eq , effective diffusion coefficient in electrolyte phase D e eff , electrolyte phase volume fraction e and open circuit voltage (OCV), have been identified by the recursive least square (RLS) algorithm with the modified DST profiles under 45, 25 and 0 °C. The simulation results indicate that the proposed model coupled with RLS algorithm can achieve high accuracy for electrochemical parameter identification in dynamic scenarios.
R Gorez - One of the best experts on this subject based on the ideXlab platform.
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discrete interval system reduction using Pade Approximation to allow retention of dominant poles
IEEE Transactions on Circuits and Systems I-regular Papers, 1997Co-Authors: O Ismail, B Bandyopadhyay, R GorezAbstract:This brief presents a method of reduction for discrete interval systems using Pade Approximation to allow the retention of dominant poles. For a given system, the denominator of the reduced model is formed by retaining the dominant poles of the original system, while the numerator is obtained by matching interval time moments. Two numerical examples illustrate the procedure.
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routh Pade Approximation for interval systems
IEEE Transactions on Automatic Control, 1994Co-Authors: B Bandyopadhyay, O Ismail, R GorezAbstract:Presents a method for the reduction of the order of interval system. The denominator of the reduced model is obtained by a direct truncation of the Routh table of the interval system. The numerator is obtained by matching the coefficients of power series expansions of the interval system and its reduced model. A numerical example illustrates the proposed procedure. >
Lei Jiang - One of the best experts on this subject based on the ideXlab platform.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 1 lithium concentration estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract To guarantee the safety, high efficiency and long lifetime for lithium-ion battery, an advanced battery management system requires a physics-meaningful yet computationally efficient battery model. The pseudo-two dimensional (P2D) electrochemical model can provide physical information about the lithium concentration and potential distributions across the cell dimension. However, the extensive computation burden caused by the temporal and spatial discretization limits its real-time application. In this research, we propose a new simplified electrochemical model (SEM) by modifying the boundary conditions for electrolyte diffusion equations, which significantly facilitates the analytical solving process. Then to obtain a reduced order transfer function, the Pade Approximation method is adopted to simplify the derived transcendental impedance solution. The proposed model with the reduced order transfer function can be briefly computable and preserve physical meanings through the presence of parameters such as the solid/electrolyte diffusion coefficients (Ds&De) and particle radius. The simulation illustrates that the proposed simplified model maintains high accuracy for electrolyte phase concentration (Ce) predictions, saying 0.8% and 0.24% modeling error respectively, when compared to the rigorous model under 1C-rate pulse charge/discharge and urban dynamometer driving schedule (UDDS) profiles. Meanwhile, this simplified model yields significantly reduced computational burden, which benefits its real-time application.
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a transfer function type of simplified electrochemical model with modified boundary conditions and Pade Approximation for li ion battery part 2 modeling and parameter estimation
Journal of Power Sources, 2017Co-Authors: Shifei Yuan, Lei Jiang, Hongjie Wu, Xi ZhangAbstract:Abstract The electrochemistry-based battery model can provide physics-meaningful knowledge about the lithium-ion battery system with extensive computation burdens. To motivate the development of reduced order battery model, three major contributions have been made throughout this paper: (1) the transfer function type of simplified electrochemical model is proposed to address the current-voltage relationship with Pade Approximation method and modified boundary conditions for electrolyte diffusion equations. The model performance has been verified under pulse charge/discharge and dynamic stress test (DST) profiles with the standard derivation less than 0.021 V and the runtime 50 times faster. (2) the parametric relationship between the equivalent circuit model and simplified electrochemical model has been established, which will enhance the comprehension level of two models with more in-depth physical significance and provide new methods for electrochemical model parameter estimation. (3) four simplified electrochemical model parameters: equivalent resistance R eq , effective diffusion coefficient in electrolyte phase D e eff , electrolyte phase volume fraction e and open circuit voltage (OCV), have been identified by the recursive least square (RLS) algorithm with the modified DST profiles under 45, 25 and 0 °C. The simulation results indicate that the proposed model coupled with RLS algorithm can achieve high accuracy for electrochemical parameter identification in dynamic scenarios.
