scholarly journals Multi-objective Pareto and GAs nonlinear optimization approach for flyback transformer

2019 ◽  
Vol 101 (3) ◽  
pp. 995-1006 ◽  
Author(s):  
Sobhi Barg ◽  
Kent Bertilsson
Keyword(s):  
High Frequency ◽  
Cost Optimization ◽  
Optimization Approach ◽  
Cost Models ◽  
Huge Number ◽  
Design And Optimization ◽  
Multi Objective ◽  
Design Variables ◽  
Transformer Design ◽  
Conduction Mode

Abstract Design and optimization of high-frequency inductive components is a complex task because of the huge number of variables to manipulate, the strong interdependence and the interaction between variables, the nonlinear variation of some design variables as well as the problem nonlinearity. This paper proposes a multi-objective design methodology of a 200-W flyback transformer in continuous conduction mode using genetic algorithms and Pareto optimality concept. The objective is to minimize loss, volume and cost of the transformer. Design variables such as the duty cycle, the winding configuration and the core shape, which have great effects on the former objectives but were neglected in previous works, are considered in this paper. The optimization is performed in discrete research space at different switching frequencies. In total, 24 magnetic materials, 6 core shapes and 2 winding configurations are considered in the database. Accurate volume and cost models are also developed to deal with the optimization in the discrete research space. The bi-objective (loss–volume) and tri-objective (loss–volume–cost) optimization results are presented, and the variations of the design variables are analyzed for the case of 60 kHz. An example of a design (30 kHz) is experimentally verified. The registered efficiency is 88% at full load.

scholarly journals RANGE EXTENDER ICE MULTI-PARAMETRIC MULTI-OBJECTIVE OPTIMIZATION

2021 ◽  
Vol 18 (1) ◽  
pp. 10
Author(s):  
Mikuláš Adámek ◽  
Rastislav Toman
Keyword(s):  
Simulation Model ◽  
Combustion Engine ◽  
Raw Materials ◽  
Single Point ◽  
Fuel Efficiency ◽  
Optimization Approach ◽  
Multi Objective Optimization ◽  
Electric Generator ◽  
Design And Optimization ◽  
Multi Objective

Range Extended Electric Vehicles (REEV) are still one of the suitable concepts for modern sustainable low emission vehicles. REEV is equipped with a small and lightweight unit, comprised usually of an internal combustion engine with an electric generator, and has thus the technical potential to overcome the main limitations of a pure electric vehicle – range anxiety, overall driving range, heating, and air-conditioning demands – using smaller battery: saving money, and raw materials. Even though several REx ICE concepts were designed in past, most of the available studies lack more complex design and optimization approach, not exploiting the advantageous single point operation of these engines. Resulting engine designs are usually rather conservative, not optimized for the best efficiency. This paper presents a multi-parametric and multi-objective optimization approach, that is applied on a REx ICE. Our optimization toolchain combines a parametric GT-Suite ICE simulation model, modeFRONTIER optimization software with various optimization strategies, and a parametric CAD model, that first provides some simulation model inputs, and second also serves for the final designs’ feasibility check. The chosen ICE concept is a 90 degrees V-twin engine, four-stroke, spark-ignition, naturally aspirated, port injected, OHV engine. The optimization goal is to find the thermodynamic optima for three different design scenarios of our concept – three different engine displacements – addressing the compactness requirement of a REx ICE. The optimization results show great fuel efficiency potential by applying our optimization methodology, following the general trends in increasing ICE efficiency, and power for a naturally aspirated concept.

Multi-objective optimization approach to reliability-based robust global optimization of electromagnetic device

2013 ◽  
Vol 33 (1/2) ◽  
pp. 191-200 ◽  
Author(s):  
Ziyan Ren ◽  
Dianhai Zhang ◽  
Chang Seop Koh
Keyword(s):  
Design Sensitivity ◽  
Target System ◽  
Stray Field ◽  
Optimization Approach ◽  
Multi Objective Optimization ◽  
The Finite Element Method ◽  
Content Type ◽  
Multi Objective ◽  
Reliability Based Design ◽  
Design Variables

Purpose – The purpose of this paper is to propose a multi-objective optimization algorithm, which can improve both the performance robustness and the constraint feasibility when the uncertainty in design variables is considered. Design/methodology/approach – Multi-objective robust optimization by gradient index combined with the reliability-based design optimization (RBDO). Findings – It is shown that searching for the optimal design of the TEAM problem 22, which can minimize the magnetic stray field by keeping the target system energy (180 MJ) and improve the feasibility of superconductivity constraint (quenching condition), is possible by using the proposed method. Originality/value – RBDO method applied to the electromagnetic problem cooperated with the design sensitivity analysis by the finite element method.

scholarly journals Design Analysis of High Frequency Linear Transformer with Ārtap Framework

2021 ◽  
Author(s):  
Tamás Orosz ◽  
Mariusz Stępień ◽  
Peter Poór
Keyword(s):  
High Frequency ◽  
Mass Density ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Design Analysis ◽  
Leakage Inductance ◽  
Design Variables ◽  
Calculation Results ◽  
Transformer Design ◽  
2D And 3D

This paper presents the design and a design analysis of a coaxial, linear transformer. This is a novel high frequency transformer concept for energy conversion. The examined transformer was designed for 1 MHz nominal frequency. One of the main advantages of the proposed transformer design is its simple winding system. It contains only two coaxial copper tubes, which can be easily manufactured and modeled with high precision. One of the key design tasks is the minimization of the leakage inductance. The inductance of the straight coils depends on the ratio of the height and the diameter of the coil. Therefore, a three-dimensional FEM analysis is sufficient to calculate the optimal length of the linear transformer. The planar 2D model and the 3D model of the transformer are presented in this paper. The accuracy of the 2D and 3D calculation results were compared to each other and to the measurements to show the applicability of the planar 2D models. Moreover, the sensitivity of the losses and the leakage inductance with respect to the winding parameters is presented. The dependencies of the design variables on the performance parameters, such as the power mass density and the leakage inductance of this transformer concept were examined. It was shown that the value of the leakage inductance is a linear function of the ratio of the length and the diameter of the transformer windings.

scholarly journals Automated Design Optimization of a Mono Tiltrotor in Hovering and Cruising States

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1155
Author(s):  
Lifang Zeng ◽  
Jianxin Hu ◽  
Dingyi Pan ◽  
Xueming Shao
Keyword(s):  
Design Parameters ◽  
Optimization Approach ◽  
Optimized Design ◽  
Multi Objective Optimization ◽  
Optimal Point ◽  
Propulsive Efficiency ◽  
Multi Objective ◽  
Coaxial Rotor ◽  
Design Variables ◽  
Single Objective

A mono tiltrotor (MTR) design which combines concepts of a tiltrotor and coaxial rotor is presented. The aerodynamic modeling of the MTR based on blade element momentum theory (BEMT) is conducted, and the method is fully validated with previous experimental data. An automated optimization approach integrating BEMT modeling and optimization algorithms is developed. Parameters such as inter-rotor spacing, blade twist, taper ratio and aspect ratio are chosen as design variables. Single-objective (in hovering or in cruising state) optimizations and multi-objective (both in hovering and cruising states) optimizations are studied at preset design points; i.e., hovering trim and cruising trim. Two single-objective optimizations result in different sets of parameter selections according to the different design objectives. The multi-objective optimization is applied to obtain an identical and compromised selection of design parameters. An optimal point is chosen from the Pareto front of the multi-objective optimization. The optimized design has a better performance in terms of the figure of merit (FM) and propulsive efficiency, which are improved by 7.3% for FM and 13.4% for propulsive efficiency from the prototype, respectively. Further aerodynamic analysis confirmed that the optimized rotor has a much more uniform load distribution along the blade span, and therefore a better aerodynamic performance in both hovering and cruising states is achieved.

Research on Structural Design and Optimization of Turbine Blade Shroud

2012 ◽  
Author(s):  
Jiang Fan ◽  
Le Han ◽  
Rongqiao Wang ◽  
Xiuli Shen ◽  
Weiwei Zeng ◽  
...  
Keyword(s):  
Turbine Blade ◽  
Structural Design ◽  
Twist Angle ◽  
Optimization Procedure ◽  
Optimization Approach ◽  
Optimized Design ◽  
Design And Optimization ◽  
Structural Intensity ◽  
Design Variables ◽  
Angle Parameter

An automatic optimization approach for the structural design of turbine blade shroud is presented and applied to the optimal design of a zigzag shroud in this paper. It integrates commercial CAD and CAE softwares into optimization procedure iSIGHT. According to the normal rules of the shroud design and experience, this paper advises a zigzag shroud which is fit for a kind of turbine blade. The parametric model of the shroud is established and the pre-twist angle parameter is taken into consideration. The structural intensity performance of the shroud, which is used to compute the optimal objective and constraints during optimization, is determined by conducting coupled thermal-structural analysis of shrouded turbine blade using the commercial Finite Element code ANSYS. Two application examples of the optimization approach are presented, with optimal objective functions of shrouded blade mass and maximum shroud contact pressure respectively. The latter includes the pre-twist angle as one of design variables. Mechanical and geometry constraints are applied on the design to ensure that the optimized design meets requirements for feasibility of engineering criteria. Simulation results from shroud optimizations by means of the optimization approach prove that the performance of the shroud can be improved significantly through structure optimization. The optimization approach provides an effective method to design and optimize the similar complicated models.

Multi-Objective Design Problem of Tire Wear and Visualization of Its Pareto Solutions2

2006 ◽  
Vol 34 (3) ◽  
pp. 170-194 ◽  
Author(s):  
M. Koishi ◽  
Z. Shida
Keyword(s):  
Inverse Problems ◽  
Conceptual Design ◽  
Dimensional Space ◽  
Design Stage ◽  
Objective Functions ◽  
Pareto Solutions ◽  
Design Problems ◽  
Multi Objective ◽  
Design Engineers ◽  
Design Variables

Abstract Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good design of tires is to solve the multi-objective design problems, i.e., inverse problems. However, due to the lack of suitable solution techniques, such problems are converted into a single-objective optimization problem before being solved. Therefore, it is difficult to find the Pareto solutions of multi-objective design problems of tires. Recently, multi-objective evolutionary algorithms have become popular in many fields to find the Pareto solutions. In this paper, we propose a design procedure to solve multi-objective design problems as the comprehensive solver of inverse problems. At first, a multi-objective genetic algorithm (MOGA) is employed to find the Pareto solutions of tire performance, which are in multi-dimensional space of objective functions. Response surface method is also used to evaluate objective functions in the optimization process and can reduce CPU time dramatically. In addition, a self-organizing map (SOM) proposed by Kohonen is used to map Pareto solutions from high-dimensional objective space onto two-dimensional space. Using SOM, design engineers see easily the Pareto solutions of tire performance and can find suitable design plans. The SOM can be considered as an inverse function that defines the relation between Pareto solutions and design variables. To demonstrate the procedure, tire tread design is conducted. The objective of design is to improve uneven wear and wear life for both the front tire and the rear tire of a passenger car. Wear performance is evaluated by finite element analysis (FEA). Response surface is obtained by the design of experiments and FEA. Using both MOGA and SOM, we obtain a map of Pareto solutions. We can find suitable design plans that satisfy well-balanced performance on the map called “multi-performance map.” It helps tire design engineers to make their decision in conceptual design stage.

scholarly journals Failure Analysis of Premature Corrosion of HF Seam-Welded Steel Pipe in Central Heating System

2021 ◽  
Author(s):  
Dorota Tyrala ◽  
Bogdan Pawlowski
Keyword(s):  
High Frequency ◽  
Energy Dispersive Spectrometry ◽  
Weld Line ◽  
Welding Process ◽  
Heating System ◽  
Bond Line ◽  
Steel Pipe ◽  
Huge Number ◽  
Welded Steel ◽  
Central Heating

AbstractPremature corrosion in the form of longitudinal cracking in a high-frequency (HF) induction seam-welded steel pipe occurred after just 24 months in service. The failed pipe was investigated to reveal the main cause of its failure, and the results of microstructural examinations (light optical microscopy, scanning electron microscopy with energy-dispersive spectrometry) suggest that the failure resulted from an HF induction welding process defect—a so-called cast weld, that is, a huge number of iron oxides in the weld line caused by insufficient ejection of the molten metal from the bond line.

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