A novel multiobjective lognormal-beta differential evolution approach for the transformer design optimization

2018 ◽  
Vol 35 (2) ◽  
pp. 955-978 ◽  
Author(s):  
Marina Tsili ◽  
Eleftherios I. Amoiralis ◽  
Jean Vianei Leite ◽  
Sinvaldo R. Moreno ◽  
Leandro dos Santos Coelho
Keyword(s):  
Differential Evolution ◽  
Design Optimization ◽  
Numerical Results ◽  
Simultaneous Optimization ◽  
Manufacturing Cost ◽  
Convergence Criteria ◽  
Content Type ◽  
Real World Applications ◽  
Transformer Design ◽  
Beta Differential Evolution

Purpose Real-world applications in engineering and other fields usually involve simultaneous optimization of multiple objectives, which are generally non-commensurable and conflicting with each other. This paper aims to treat the transformer design optimization (TDO) as a multiobjective problem (MOP), to minimize the manufacturing cost and the total owing cost, taking into consideration design constraints. Design/methodology/approach To deal with this optimization problem, a new method is proposed that combines the unrestricted population-size evolutionary multiobjective optimization algorithm (UPS-EMOA) with differential evolution, also applying lognormal distribution for tuning the scale factor and the beta distribution to adjust the crossover rate (UPS-DELFBC). The proposed UPS-DELFBC is useful to maintain the adequate diversity in the population and avoid the premature convergence during the generational cycle. Numerical results using UPS-DELFBC applied to the transform design optimization of 160, 400 and 630 kVA are promising in terms of spacing and convergence criteria. Findings Numerical results using UPS-DELFBC applied to the transform design optimization of 160, 400 and 630 kVA are promising in terms of spacing and convergence criteria. Originality/value This paper develops a promising UPS-DELFBC approach to solve MOPs. The TDO problems for three different transformer specifications, with 160, 400 and 630 kVA, have been addressed in this paper. Optimization results show the potential and efficiency of the UPS-DELFBC to solve multiobjective TDO and to produce multiple Pareto solutions.

Novel Gamma Differential Evolution Approach for Multiobjective Transformer Design Optimization

2013 ◽  
Vol 49 (5) ◽  
pp. 2121-2124 ◽  
Author(s):  
Leandro dos Santos Coelho ◽  
Viviana Cocco Mariani ◽  
Mauricio V. Ferreira da Luz ◽  
Jean Vianei Leite
Keyword(s):  
Differential Evolution ◽  
Design Optimization ◽  
Transformer Design ◽  
Evolution Approach

Design optimization of ferrite assisted synchronous reluctance motor using multi-objective differential evolution algorithm

2017 ◽  
Vol 36 (1) ◽  
pp. 219-239 ◽  
Author(s):  
Nagarajan V.S. ◽  
Balaji Mahadevan ◽  
Kamaraj V. ◽  
Arumugam R. ◽  
Ganesh Nagarajan ◽  
...  
Keyword(s):  
Differential Evolution ◽  
Design Optimization ◽  
Torque Ripple ◽  
Multiple Objectives ◽  
Variable Speed ◽  
Content Type ◽  
Multi Objective ◽  
Synchronous Reluctance Motor ◽  
Reluctance Motor ◽  
Optimization Routine

Purpose The purpose of this paper is performance enhancement of ferrite-assisted synchronous reluctance (FASR) motor using multi-objective differential evolution (MODE) algorithm, considering the significant geometric design parameters. Design/methodology/approach This work illustrates the optimization of FASR motor using MODE algorithm to enhance the performance of the motor considering barrier angular positions, magnet height, magnet axial length, flux barrier angles of the rotor and air gap length. In the optimization routine to determine the performance parameters, generalized regression neural network-based interpolation is used. The results of MODE are validated with multi-objective particle swarm optimization algorithm and multi-objective genetic algorithm. Findings The design optimization procedure developed in this work for FASR motor aims at achieving multiple objectives, namely, average torque, torque ripple and efficiency. With multiple objectives, it is essential to give the designer the tradeoff between different objectives so as to arrive at the best design suitable for the application. The results obtained in this work justify the application of the MODE approach for FASR motor to determine the various feasible solutions within the bounds of the design. Research limitations/implications Analysis, design and optimization of synchronous reluctance motor has been explored in detail to establish its potential for variable speed applications. In recent years, the focus is toward the electromagnetic design of hybrid configurations such as FASR motor. It is in this preview this work aims to achieve optimal design of FASR motor using multi-objective optimization approach. Practical/implications The results of this work will supplement and encourage the application of FASR motor as a viable alternate for variable speed drive applications. In addition, the application of MODE to arrive at better design solutions is demonstrated. Originality/value The approach presented in this work focuses on obtaining enhanced design of FASR motor considering average torque, torque ripple and efficiency as performance measures. The posteriori analysis of optimization provides an insight into the choice of parameters involved and their effects on the design of FASR motor. The efficacy of the optimization routine is justified in comparison with other multi-objective algorithms.

scholarly journals Simultaneous Optimization of Magnet and Flux Barrier in IPMSM by Differential Evolution

2016 ◽  
Vol 24 (3) ◽  
pp. 106-111
Author(s):  
Kosuke UKITA ◽  
Kota ISHIKAWA ◽  
Wataru KITAGAWA ◽  
Takaharu TAKESHITA
Keyword(s):  
Differential Evolution ◽  
Simultaneous Optimization

Numerical simulation of vapor bubble growth on a vertical superheated wall using lattice Boltzmann method

2015 ◽  
Vol 25 (5) ◽  
pp. 1214-1230 ◽  
Author(s):  
Tao Sun ◽  
Weizhong Li ◽  
Bo Dong
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Phase Change ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Nucleate Boiling ◽  
Numerical Results ◽  
Heat Transfer Mechanism ◽  
Content Type ◽  
Boltzmann Method

Purpose – The purpose of this paper is to test the feasibility of lattice Boltzmann method (LBM) for numerical simulation of nucleate boiling and transition boiling. In addition, the processes of nucleate and transition boiling on vertical wall are simulated. The heat transfer mechanism is discussed based on the evolution of temperature field. Design/methodology/approach – In this paper, nucleate boiling and transition boiling are numerically investigated by LBM. A lattice Boltzmann (LB) multiphase model combining with a LB thermal model is used to predict the phase-change process. Findings – Numerical results are in good agreement with existing experimental results. Numerical results confirm the feasibility of the hybrid LBM for direct simulations of nucleate and transition boiling. The data exhibit correct parametric dependencies of bubble departure diameter compared with experimental correlation and relevant references. Research limitations/implications – All the simulations are performed in two-dimensions in this paper. In the future work, the boiling process will be simulated in three-dimensional. Practical implications – This study demonstrated a potential model that can be applied to the investigation of phase change heat transfer, which is one of the effective techniques for enhance the heat transfer in engineering. The numerical results can be considered as a basic work or a reference for generalizing LB method in the practical application about nucleate boiling and transition boiling. Originality/value – The hybrid LBM is first used for simulation of nucleate and transition boiling on vertical surface. Heat transfer mechanism during boiling is discussed based on the numerical results.

Influence of velocity head on filling transients in a branched pipeline

2018 ◽  
Vol 35 (7) ◽  
pp. 2502-2513 ◽  
Author(s):  
Ling Wang ◽  
Fujun Wang ◽  
Bryan William Karney ◽  
Ahmad Malekpour ◽  
Zhengwei Wang
Keyword(s):  
Method Of Characteristics ◽  
Energy Equation ◽  
Transient Flow ◽  
Numerical Results ◽  
Velocity Head ◽  
Piezometric Head ◽  
Content Type ◽  
High Point ◽  
Hydraulic Transient ◽  
Column Separation

Purpose The velocity head is usually neglected in the energy equation for a pipeline junction when one-dimensional (1D) hydraulic transient flow is solved by method of characteristics. The purpose of this paper is to investigate the effect of velocity head on filling transients in a branched pipeline by an energy equation considering velocity head. Design/methodology/approach An interface tracking method is used to locate the air–water interface during pipeline filling. The pressured pipe flow is solved by a method of characteristics. A discrete gas cavity model is included to permit the occurrence of column separation. A universal energy equation is built by considering the velocity head. The numerical method is provisionally verified in a series pipeline and the numerical results and experimental data accord well with each other. Findings The numerical results show that some differences in filling velocity and piezometric head occur in the branched pipeline. These differences arise because the velocity head in the energy equation can become an important contributor to the hydraulic response of the system. It is also confirmed that a local high point in the profile is apt to experience column separation during rapid filling. Significantly, the magnitude of overpressure and cavity volume induced by filling transients at the local high point is predicted to increase with the velocity in the pipes. Originality/value The velocity head in the energy equation for a pipeline junction could play an important role in the prediction of filling velocity, piezometric head and column separation phenomenon, which should be given more attention in 1D hydraulic transient analysis.

Design Optimization of a Special Class of Steel Structures via Genetic Algorithms and Stochastic Sampling

2009 ◽  
Author(s):  
Karim Hamza ◽  
Ashraf O. Nassef ◽  
Mohammed Shalaby
Keyword(s):  
Genetic Algorithms ◽  
Design Optimization ◽  
Special Class ◽  
Steel Structures ◽  
Sampling Technique ◽  
Manufacturing Cost ◽  
Stochastic Sampling ◽  
Optimization Task ◽  
Consistent Performance ◽  
Continuous And Discrete Variables

This paper addresses the design optimization of a special class of steel structures, which is clear-span building built up via off-shelf standard steel-sections. The problem is of particular importance in small to medium span buildings due to an attractive opportunity for reduction of the manufacturing cost compared to trusses and custom-built beams. The problem is also difficult from an optimization perspective as it exhibits both continuous and discrete variables, as well as discontinuities and flat regions in the topology of the objective function. Genetic algorithms (GA) and a special stochastic sampling technique are considered for the problem, as well as a mixed GA and stochastic sampling approach. The stochastic sampling is guided via heuristic rules based on knowledge specific to the problem, and is thus perceived well suited to the optimization task. While all the tested algorithms produced satisfactory results, the mixed approach seemed to yield the most consistent performance.

scholarly journals FEM Based Preliminary Design Optimization in Case of Large Power Transformers

2019 ◽  
Author(s):  
Tamás Orosz ◽  
David Pánek ◽  
Pavel Karban
Keyword(s):  
Design Optimization ◽  
Design Process ◽  
Optimization Problems ◽  
Optimization Method ◽  
Power Transformers ◽  
Design Stage ◽  
Preliminary Design ◽  
Large Power ◽  
Custom Made ◽  
Transformer Design

Since large power transformers are custom-made, and their design process is a labor-intensive task, their design process is split into different parts. In tendering, the price calculation is based on the preliminary design of the transformer. Due to the complexity of this task, it belongs to the most general branch of discrete, non-linear mathematical optimization problems. Most of the published algorithms are using a copper filling factor based winding model to calculate the main dimensions of the transformer during this first, preliminary design step. Therefore, these cost optimization methods are not considering the detailed winding layout and the conductor dimensions. However, the knowledge of the exact conductor dimensions is essential to calculate the thermal behaviour of the windings and make a more accurate stray loss calculation. The paper presents a novel, evolutionary algorithm-based transformer optimization method which can determine the optimal conductor shape for the windings during this examined preliminary design stage. The accuracy of the presented FEM method was tested on an existing transformer design. Then the results of the proposed optimization method have been compared with a validated transformer design optimization algorithm.

Computational investigation of turbulent jet impinging onto rotating disk

2007 ◽  
Vol 17 (3) ◽  
pp. 284-301 ◽  
Author(s):  
A.C. Benim ◽  
K. Ozkan ◽  
M. Cagan ◽  
D. Gunes
Keyword(s):  
Boundary Conditions ◽  
Isotropic Turbulence ◽  
Domain Size ◽  
Rotating Disk ◽  
Turbulent Jet ◽  
Turbulence Structure ◽  
Computational Domain ◽  
Convergence Criteria ◽  
Computational Investigation ◽  
Content Type

PurposeThe main purpose of the paper is the validation of a broad range of RANS turbulence models, for the prediction of flow and heat transfer, for a broad range of boundary conditions and geometrical configurations, for this class of problems.Design/methodology/approachTwo‐ and three‐dimensional computations are performed using a general‐purpose CFD code based on a finite volume method and a pressure‐correction formulation. Special attention is paid to achieve a high numerical accuracy by applying second order discretization schemes and stringent convergence criteria, as well as performing sensitivity studies with respect to the grid resolution, computational domain size and boundary conditions. Results are assessed by comparing the predictions with the measurements available in the literature.FindingsA rather unsatisfactory performance of the Reynolds stress model is observed, in general, although the contrary has been expected in this rotating flow, exhibiting a predominantly non‐isotropic turbulence structure. The best overall agreement with the experiments is obtained by the k‐ω model, where the SST model is also observed to provide a quite good performance, which is close to that of the k‐ω model, for most of the investigated cases.Originality/valueTo date, computational investigation of turbulent jet impinging on to “rotating” disk has not received much attention. To the best of the authors' knowledge, a thorough numerical analysis of the generic problem comparable with present study has not yet been attempted.

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