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Optimal energy storage system allocation and operation for improving wind power penetration

IET GENERATION TRANSMISSION & DISTRIBUTION 2015年第16期9卷 2672-2678页

作者： Zheng, Le Hu, Wei Lu, Qiuyu Min, Yong Tsinghua Univ Dept Elect Engn State Key Lab Power Syst Beijing 100084 Peoples R China

In recent years, the energy storage system (ESS) has been demonstrated to be involved in many aspects of the integration of wind power. For ESS application, ESS allocation of the installation location, power rating, and energy rating is the first concern. Different from previous studies, this study emphasises the significance of the ESS operation in the study of ESS allocation. A bi-level-programming-based model is proposed to take the interaction of allocation and operation into consideration at the same time, with the external level optimising allocation and the internal level optimising operation. The complexity assessment and solution algorithm of the model is also discussed. Next, a genetic numerical algorithm is proposed to solve the bi-level model. The authors' results were tested on a modified IEEE 39 bus system and a provincial regional power system to verify both the flexibility and applicability of the proposed model and algorithm. This model is useful for various types of ESS and provides a foundation for ESS application.

关键词： wind power plants energy storage optimisation optimal energy storage system allocation wind power penetration ESS allocation installation location power rating energy rating bilevel-programming-based model external level optimising allocation internal level optimising operation complexity assessment solution algorithm genetic numerical algorithm modified IEEE 39 bus system provincial regional power system

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STRUCTURAL MODEL CORRELATION USING LARGE ADMISSIBLE PERTURBATIONS IN COGNATE SPACE

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AIAA JOURNAL 1991年第12期29卷 2222-2232页

作者： BERNITSAS, MM TAWEKAL, RL University of Michigan Ann Arbor Michigan 48109

A nonlinear perturbation method is developed to solve the problem of correlating a finite element model (FEM) to a structure for which an incomplete set of natural frequencies and mode shapes and/or some static deflections have been measured. The solution algorithm can handle differences between FEM and structure, in design variables and response, as large as 100-300%, depending on the scale of the structure and correlation measures. This is achieved incrementally by making inadmissible predictions, identifying the modal cognate space relevant to the correlation measures, and making admissible corrections in the cognate space. The developed computer code postprocesses results of the FEM modal and/or static analyses of the initial model only. No additional finite element analysis is required. Lagrange multipliers reveal the dominant correlation requirements and the active admissible cognate subspace. Depending on the number of correlation variables and measures, an optimal, a unique, or an inadmissible minimal error solution may be produced. Beam and offshore tower examples are used to lest the algorithm and investigate conflicting requirements, definition of admissible cognate space, limits of allowable differences between FEM and structure, accuracy, and cost of the nonlinear perturbation method.

关键词： Structural Modeling Finite Element Analysis Lagrange Multipliers Perturbation Method solution algorithm Nastran Structural Element Mathematical Models Dynamic Response Computing

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Behavior of concrete-filled steel tubular column at large axial deformation

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STRUCTURES 2024年 70卷

作者： Qi, Hong-Hui Li, Guo-Qiang Lou, Guo-Biao Tongji Univ Coll Civil Engn Shanghai 200092 Peoples R China State Key Lab Disaster Reduct Civil Engn Shanghai 200092 Peoples R China

This paper develops a three-stage load-bearing capacity formulation for concrete-filled steel tubular (CFST) columns throughout the entire deformation process, comprising three stages: prior to buckling, buckling, and large deformation, each characterized by distinct load-bearing mechanisms. The concept of vaulting pole action is introduced to describe the column behavior with large axial deformation. An analytical method is proposed to determine the load-bearing capacity of CFST columns at large axial deformation. To validate the theoretical approach, the axial load test was conducted on the CFST column until large deformation, measuring both the structural force and deformation responses. The experimental results confirmed the substantial load-bearing capacity at large axial deformation, retaining 57 % of its maximum load-bearing capacity when the axial deformation reached one twenty-fifth of the column length. Additionally, a numerical approach using the Newton-Raphson method in displacement control mode was also presented to analyze CFST column behavior under large deformation. The numerical results demonstrate that geometric dimensions and the constraining factor significantly affect the column behavior at large deformation, with the relative load-bearing capacity factor (eta lb) decreasing as the effective length increases and increasing as the constraining factor rises. The parametric study using the analytical method demonstrates that reducing the slenderness and enhancing the material strength can increase the load-bearing capacity of CFST columns under large axial deformation. The considerable load-bearing capacity retained at large deformation highlights the importance of vaulting pole action and suggests that columns should not be simply removed when evaluating the structural collapse of buildings.

关键词： Concrete-filled steel tubular column Large axial deformation Vaulting pole action Relative load-bearing capacity factor solution algorithm

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Unstructured-Grid Third-Order Finite Volume Discretization Using a Multistep Quadratic Data-Reconstruction Method

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AIAA JOURNAL 2010年第4期48卷 808-817页

作者： Caraeni, D. Hill, D. C. ANSYS Inc Lebanon NH 03766 USA

Finite volume discretizations on unstructured grids that are more than second-order-accurate have not yet gained wide acceptance. This is due to the high computational cost and memory requirements of the proposed schemes and the technical difficulties in achieving a high-order-accurate solution. It is especially true when considering flows in complex geometries. In this paper, a third-order cell-centered finite volume discretization is detailed that is based on quadratic data recovery, which is computationally efficient and has optimal memory requirements. The density-based flow-solver discretization and solution algorithm are described briefly, followed by a detailed presentation of the least-squares-based multistep quadratic data-reconstruction methodology proposed here. The paper is concluded with numerical examples to verify the accuracy and numerical efficiency of this high-order finite volume discretization.

关键词： Unstructured Grid solution algorithm Finite Volume Scheme Angle of Attack Mach Number Riemann Problem Turbulent Flow Primitive Variable Singular Value Decomposition Computing

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Thrust generation caused by flapping airfoils in a biplane configuration

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JOURNAL OF AIRCRAFT 2003年第3期40卷 509-515页

作者： Tuncer, IH Kaya, M Middle E Tech Univ Dept Aerosp Engn TR-06531 Ankara Turkey

Unsteady, viscous flows over flapping airfoils in a biplane configuration are computed on moving overset grids. The overset grid solutions are obtained in parallel in a distributed memory environment. Unsteady flowfields are described by particle traces: Time-averaged thrust values are obtained from the integration of the unsteady drag coefficient. It is shown that airfoils in a biplane configuration and oscillating in a combined pitch and plunge motion with a proper phase shift between them produce 20-40% more thrust than a single flapping airfoil. Turbulence in the flow further augments the thrust generation. For a maximum thrust at a given flapping frequency, an optimization of the flapping motion parameters is needed.

关键词： Freestream Velocity Biplane Flapping Airfoil Vortices Flapping Wing solution algorithm Computer Cluster Spalart Allmaras Turbulence Model Propulsion Technology Aerodynamic Performance

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Solving inverse optimal control problems via value functions to global optimality

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JOURNAL OF GLOBAL OPTIMIZATION 2019年第2期74卷 297-325页

作者： Dempe, Stephan Harder, Felix Mehlitz, Patrick Wachsmuth, Gerd Tech Univ Bergakad Freiberg Fac Math & Comp Sci D-09596 Freiberg Germany Brandenburg Tech Univ Cottbus Senftenberg Chair Optimal Control Inst Math D-03046 Cottbus Germany

In this paper, we show how a special class of inverse optimal control problems of elliptic partial differential equations can be solved globally. Using the optimal value function of the underlying parametric optimal control problem, we transfer the overall hierarchical optimization problem into a nonconvex single-level one. Unfortunately, standard regularity conditions like Robinson's CQ are violated at all the feasible points of this surrogate problem. It is, however, shown that locally optimal solutions of the problem solve a Clarke-stationarity-type system. Moreover, we relax the feasible set of the surrogate problem iteratively by approximating the lower level optimal value function from above by piecewise affine functions. This allows us to compute globally optimal solutions of the original inverse optimal control problem. The global convergence of the resulting algorithm is shown theoretically and illustrated by means of a numerical example.

关键词： Bilevel optimal control Global optimization Inverse optimal control Optimality conditions solution algorithm

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Direct search algorithm for bilevel programming problems

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COMPUTATIONAL OPTIMIZATION AND APPLICATIONS 2011年第1期49卷 1-15页

作者： Mersha, Ayalew Getachew Dempe, Stephan Tech Univ Bergakad Freiberg Dept Math & Comp Sci D-09596 Freiberg Germany

In this paper, we study the application of a class of direct search methods to bilevel programming with convex lower level problems with strongly stable optimal solutions. In those methods, directions of descent in each iterations are selected within a finite set of directions. To guarantee the existence of such a finite set, we investigate the relation between the aperture of a descent cone at a non stationary point and the vector density of a finite set of directions. It is shown that the direct search method converges to a Clarke stationary point of the bilevel programming problem.

关键词： Bilevel programming Nonsmooth optimization solution algorithm Direct search algorithm Clarke stationary solution

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VISCOUS SHOCK-LAYER FLOWFIELD ANALYSIS BY AN EXPLICIT-IMPLICIT METHOD

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AIAA JOURNAL 1985年第5期23卷 723-732页

作者： GUPTA, RN GNOFFO, PA MACCORMACK, RW UNIV WASHINGTON DEPT AERONAUT & ASTRONAUTSEATTLEWA 98195

The present work extends the recently reported implicit analog of MacCormack’s earlier, widely used explicit method to external axisymmetric laminar flows with strong entropy gradients. The details of the “numerics” of the implicit part are provided in a body-oriented coordinate system with a moving outer (shock) boundary during the transient part of the solutions. The limiting values of the Courant number are obtained when the shock boundary is treated explicitly. The solution algorithm outlined includes the treatment of the source term associated with the equations in weak conservation form. From the results obtained for two sample problems, it becomes clear that accuracy of predictions is, indeed, very good at higher values of the Courant number. There is a significant saving in overall computing time, depending on the Courant number used and the flow Reynolds number. These properties combined with the simplicity of programming of the implicit analog may appeal to researchers in the analysis of three-dimensional flow problems. © 1985 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.

关键词： Shock Layers In Compressible Viscous Flows Numerical Integration Freestream Mach Number Courant Friedrichs Lewy Heat Transfer Coefficients solution algorithm Gas Constant Viscosity Navier Stokes Equations

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A Simple Lambert algorithm

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2008年第6期31卷 1587-1594页

作者： Avanzini, Giulio Politecn Torino Dept Aerosp Engn I-10129 Turin Italy

A classic result for the two-point boundary value problem in the framework of Keplerian motion allows the derivation of a novel parametrization of orbits passing through two arbitrary points in space. In particular, it is shown that these orbits *** unambiguously identified in terms of their eccentricity vector component in the direction perpendicular to the chord connecting the two points. The parametrization, in terms of transverse eccentricity component, lends itself to an efficient and intuitive solution algorithm for the classical Lambert problem, that is, the determination of the orbit that connects two points in space in a prescribed time. Although, from the computational point of view, the resulting numerical procedure does not provide advantages over the elegant Battin's method, its derivation is considerably less demanding from the mathematical standpoint and physically more intuitive.

关键词： Lambert algorithm Hyperbolic Trajectories Periapsis solution algorithm Elliptical Transfer Orbit Boundary Value Problems Numerical algorithms Kepler's Equation Jet Propulsion Laboratory Trajectory Optimization

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Strategic planning, design, and development of the shale gas supply chain network

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AICHE JOURNAL 2014年第6期60卷 2122-2142页

作者： Cafaro, Diego C. Grossmann, Ignacio E. INTEC UNL CONICET RA-3000 Santa Fe Argentina Carnegie Mellon Univ Dept Chem Engn Pittsburgh PA 15213 USA

The long-term planning of the shale gas supply chain is a relevant problem that has not been addressed before in the literature. This article presents a mixed-integer nonlinear programming (MINLP) model to optimally determine the number of wells to drill at every location, the size of gas processing plants, the section and length of pipelines for gathering raw gas and delivering processed gas and by-products, the power of gas compressors, and the amount of freshwater required from reservoirs for drilling and hydraulic fracturing so as to maximize the net present value of the project. Because the proposed model is a large-scale nonconvex MINLP, we develop a decomposition approach based on successively refining a piecewise linear approximation of the objective function. Results on realistic instances show the importance of heavier hydrocarbons to the economics of the project, as well as the optimal usage of the infrastructure by properly planning the drilling strategy. (c) 2014 American Institute of Chemical Engineers AIChE J, 60: 2122-2142, 2014

关键词： mixed-integer nonlinear programming approach strategic plan supply chain shale gas solution algorithm

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