| 1. |
- Li, Mengting, et al.
(author)
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Dispatch Planning of a Wide-Area Wind Power-Energy Storage Scheme Based on Ensemble Empirical Mode Decomposition Technique
- 2021
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In: IEEE Transactions on Sustainable Energy. - 1949-3029 .- 1949-3037. ; 12:2, s. 1275-1288
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Journal article (peer-reviewed)abstract
- This paper addresses the challenging task of developing a procedure for the day-ahead dispatch planning of wind power which emanates from a wide geographical area. Using the complete ensemble empirical mode decomposition technique, it is shown that the low-frequency components of the area aggregated wind power account for the largest proportions of the perturbing energy harnessed from the wind. By taking advantage of the slow-varying characteristics of the low-frequency components, accurate forecast of these components is readily obtained and incorporated into the developed dispatch planning procedure. The dispatchability of the wide-area wind generation is facilitated by the buffering actions offered by a centralized power dispatch energy storage system, operating under a proposed power flows control strategy. The efficacy of the developed procedure is illustrated using a pumped hydroelectric system as the dispatch energy storage medium.
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| 2. |
- Li, Yang, 1984, et al.
(author)
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A Physics-Based Distributed-Parameter Equivalent Circuit Model for Lithium-ion Batteries
- 2019
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In: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 299, s. 451-469
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Journal article (peer-reviewed)abstract
- A physics-based equivalent circuit model (ECM) is derived by applying the finite volume method to a pseudo-two-dimensional (P2D) model of lithium-ion (Li-ion) batteries. Only standard passive components are used to construct the equivalent circuit, which reflects the fact that a Li-ion battery is an energy storage device. Voltages across and currents through the circuit elements in the ECM are identified with the respective internal electrochemical processes in the battery, thus allowing the parametric values of circuit elements to be expressed as functions of the Li-ion concentrations and temperature. Variations in the parametric values across the thickness of the battery lead to a distributed-parameter ECM amenable for a wide range of applications. Furthermore, in contrast to existing reduced-order models of Li-ion battery which are described by differential algebraic equations, the ECM is governed by ordinary differential equations wherein all the circuit components are expressed as explicit functions of the state and input variables. Hence, the developed model allows solutions to be found directly using matrix algebra, resulting in rapid simulation study suitable for the development of computationally efficient real-time battery control algorithm. Results of simulation based on the developed distributed-parameter ECM show close agreement with those obtained from a partial differential equation based P2D model under a wide range of applied current rates, but at a much reduced computational burden.
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| 3. |
- Li, Yang, 1984, et al.
(author)
-
Combined Primary Frequency and Virtual Inertia Response Control Scheme of Variable-Speed Dish-Stirling System
- 2020
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In: IEEE Access. - 2169-3536 .- 2169-3536. ; 8, s. 151719-151730
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Journal article (peer-reviewed)abstract
- The potential of variable-speed dish-Stirling (VSDS) solar-thermal generating plant in providing grid frequency support is investigated. In the proposed VSDS frequency support control scheme, the reference speed of the Stirling engine is regulated to track a deloaded power curve which is governed by the solar insolation level. The gain of a supplementary speed-frequency droop controller is then set to meet the primary frequency control requirement. Further uniqueness of the VSDS control scheme pertains to the provision of virtual inertia response by regulating the kinetic energy in the rotating mass of the engine-generator and the thermal energy in the heat absorber/receivers. Small-signal analysis shows that the frequency support scheme is inherently stable, and it will provide higher degree of damping as the penetration level of the VSDS system and/or the solar insolation level increase. The efficacy of the proposed scheme is validated by computer simulation.
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| 4. |
- Li, Yang, 1984, et al.
(author)
-
Design of Minimum Cost Degradation-Conscious Lithium-Ion Battery Energy Storage System to Achieve Renewable Power Dispatchability
- 2020
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In: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 260
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Journal article (peer-reviewed)abstract
- The application of lithium-ion (Li-ion) battery energy storage system (BESS) to achieve the dispatchability of a renewable power plant is examined. By taking into consideration the effects of battery cell degradation evaluated using electrochemical principles, a power flow model (PFM) of the BESS is developed specifically for use in system-level study. The PFM allows the long-term performance and lifetime of the battery be predicted as when the BESS is undertaking the power dispatch control task. Furthermore, a binary mode BESS control scheme is proposed to prevent the possible over-charge/over-discharge of the BESS due to the uncertain renewable input power. Analysis of the resulting new dispatch control scheme shows that a proposed adaptive BESS state of energy controller can guarantee the stability of the dispatch process. A particle swarm optimization algorithm is developed and is incorporated into a computational procedure for which the optimum battery capacity and power rating are determined, through minimizing the capital cost of the BESS plus the penalty cost of violating the dispatch power commitment. Results of numerical examples used to illustrate the proposed design approach show that in order to achieve hourly-constant power dispatchability of a 100-MW wind farm, the minimum-cost Li-ion BESS is rated 31-MW/22.6-MWh.
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| 5. |
- Li, Yang, 1984, et al.
(author)
-
Design of Variable-Speed Dish-Stirling Solar-Thermal Power Plant for Maximum Energy Harness
- 2015
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In: IEEE Transactions on Energy Conversion. - 1558-0059 .- 0885-8969. ; 30:1, s. 394-403
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Journal article (peer-reviewed)abstract
- Analysis on a developed dynamic model of the dish-Stirling (DS) system shows that maximum solar energy harness can be realized through controlling the Stirling engine speed. Toward this end, a control scheme is proposed for the doubly fed induction generator coupled to the DS system, as a means to achieve maximum power point tracking as the solar insolation level varies. Furthermore, the adopted fuzzy supervisory control technique is shown to be effective in controlling the temperature of the receiver in the DS system as the speed changes. Simulation results and experimental measurements validate the maximum energy harness ability of the proposed variable-speed DS solar-thermal system.
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| 6. |
- Li, Yang, 1984, et al.
(author)
-
Development of a Degradation-Conscious Physics-Based Lithium-ion Battery Model for Use in Power System Planning Studies
- 2019
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In: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 248, s. 512-525
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Journal article (peer-reviewed)abstract
- A computationally-efficient and reliable method is developed to permit the simultaneous assessment of both the short- and long-term performance of lithium-ion battery in power system planning studies. Toward this end, a physics-based equivalent circuit model of the lithium-ion battery is derived in which side reaction-induced degradation of the battery is included. Whence a computational procedure is developed to enable the parametric values of the circuit elements in the equivalent circuit model to be automatically updated as the battery operates. The resulting model allows the increase in the internal resistance and the decrease in the energy storage capacity of the battery to be determined, based solely on the information of the power flows at the battery terminals. Dynamic simulation results obtained using the developed equivalent circuit model are shown to be in close agreement with those obtained from well-established electrochemical models, but at a much reduced computational burden.
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| 7. |
- Li, Yang, 1984, et al.
(author)
-
Dish-Stirling Solar Power Plants: Modeling, Analysis and Control of Receiver Temperature
- 2014
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In: IEEE Transactions on Sustainable Energy. - 1949-3029 .- 1949-3037. ; 5:2, s. 398-407
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Journal article (peer-reviewed)abstract
- A simplified adiabatic model of the Stirling engine is developed for the study of a grid-connected dish-Stirling solar-thermal power plant. The model relates the average values of the engine state variables and also takes into account the engine losses. As the engine is shown to exhibit nonminimum phase behavior, an improved temperature control scheme for the engine heat absorber is developed. By including the engine speed, pressure, and solar insolation limits into the analysis, a steady-state feasible operating regime of the solar-thermal power plant is obtained. A maximum solar energy harness is shown to be achievable through the variable speed operation of the power plant.
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| 8. |
- Li, Yang, 1984, et al.
(author)
-
Model Order Reduction Techniques for Physics-Based Lithium-ion Battery Management: A Survey
- 2022
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In: IEEE Industrial Electronics Magazine. - 1941-0115 .- 1932-4529. ; 16:3, s. 36-51
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Journal article (peer-reviewed)abstract
- To unlock the promise of electrified transportation and smart grid, emerging advanced battery management systems (BMSs) shall play an important role in health-aware monitoring, diagnosis, and control of widely used lithium-ion (Li-ion) batteries. Sophisticated physics-based battery models incorporated in the advanced BMS can offer valuable battery internal information to achieve improved operational safety, reliability and efficiency, and to extend the lifetime of the batteries. However, developed from the fundamental electrochemical and thermodynamic principles, the rigorous physics-based models are saddled with exceedingly high cognitive and computational complexity for practical applications. This article reviews prevailing order reduction techniques of physics-based Li-ion battery models to facilitate the development of next-generation BMSs. We analyze and comparatively characterize these techniques, mainly from perspectives of model fidelity, computational efficiency, and the scope of applications. By representing many effective and flexible reduced-order models as equivalent circuits, designers and practitioners, who do not have electrochemical expertise but with knowledge of circuit theory, can readily gain insights into multi-physical dynamics as well as their coupling effects inside the batteries. In addition, recommendations are made on how to select appropriate physics-based models for various model-based applications in battery management. Finally, the prospect of physical model-enabled BMSs is discussed, including the potential challenges and future research directions.
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| 9. |
- Li, Yang, 1984, et al.
(author)
-
Primary Frequency Control Scheme for a Fixed-Speed Dish-Stirling Solar-Thermal Power Plant
- 2018
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In: IEEE Transactions on Power Systems. - 0885-8950 .- 1558-0679. ; 33:2, s. 2184-2194
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Journal article (peer-reviewed)abstract
- The ability of an induction generator-based dish-Stirling (DS) solar-thermal power plant in providing primary frequency control is examined. A dynamic model of the power plant is developed, in which the receiver/absorber temperature of the Stirling engine is allowed to vary. Primary frequency control is achieved through the adaptive regulation of the receiver temperature set-point and the droop setting of the output power-temperature characteristics of the DS system. However, the penetration level of the solar-thermal generation into the grid system has to be constrained to avoid the onset of instability due to the nonminimum phase characteristics of the DS system. The transient droop compensation technique is then proposed to alleviate the instability issue and results in an increase in the allowable DS penetration level.
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| 10. |
- Tran, Ngoc Tham, et al.
(author)
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A Computationally Efficient Coupled Electrochemical-Thermal Model for Large Format Cylindrical Lithium Ion Batteries
- 2019
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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 166:13, s. A3059-A3071
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Journal article (peer-reviewed)abstract
- We present a one-dimensional, radial, coupled degradation-electrochemical-thermal (DET) model of a large format cylindrical lithium ion cell. The model consists of reduced order equations that describe the electrochemical phenomena, including that associated with degradation, coupled with an approximate model of thermal behavior. The reduced order electrochemical model, which is approximated from the pseudo-two-dimensional (P2D) electrochemical model using a Padé approximation method, computes the variation of electrochemical variables and heat generation terms. Simultaneously, a coupled thermal model computes the temperature distribution in the radial direction of the cell. The results from DET model compare favorably to those obtained from solving the 1D radial coupled degradation-electrochemical-thermal partial differential equations in COMSOL Multiphysics, however the DET model returns these results in significantly reduced computational times. Importantly, the model capability in providing insightful information of cell degradation and temperature in a computationally efficient manner paves the way for the health-conscious, real-time optimal control of large format cylindrical cells.
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| 11. |
- Tran, Ngoc Tham, et al.
(author)
-
A Padé Approximate Model of Lithium Ion Batteries
- 2018
-
In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 165:7
-
Journal article (peer-reviewed)abstract
- We present a reduced order model for a lithium ion battery in which Padé approximants are used to simplify complex, transcendental, transfer functions associated with the linearized, pseudo 2-dimensional (P2D) electrochemical model of the battery. The resulting transfer functions take the form of simple, rational polynomial functions, which can be used to compute any variable at any location within a one-dimensional representation of the battery domain. Corrections for nonlinear behavior are also incorporated into the reduced model. The results obtained using the reduced model compare favorably to those from the full (nonlinear) P2D model and the computational time required to produce these results is significantly reduced. Importantly, the form of the reduced model means that variables can be evaluated at specific discrete locations within the cell domain, without the need to compute all values of the variable at all discrete locations, as is the case with the spatial discretization methods most commonly used to implement the P2D model. We show that this results in further significant time savings and enhances the suitability of the model for variety of applications.
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