Optimization of selected electroheat models based on calibration of material properties
Faculty of electrical engineering, University of West Bohemia, Czech Republic
A novel technique of optimizing selected models of electroheat processes (laser or induction-assisted laser welding, cladding, etc.) is presented, based on calibration of temperature-dependent material properties. These properties often exhibit uncertainties that negatively influence the quality of results. Their calibration starts from experimental investigation and evaluation of temperature profiles of welds or tracks and the goal is to obtain the same profiles by solving the numerical models. The technique is illustrated with an example of induction-assisted laser welding.
A Study on the Increase of Inductance according to the Construction of an Induction Heater for Electric Vehicles
hanbat national university, Korea, Republic of (South Korea)
Induction heaters have a faster heating rate than positive-temperature-coefficient (PTC) heaters. In addition, PTC heaters have weight reduction limits due to the complicated insulation structure of the package. On the other hand, induction heaters have no insulation structure, and their production is simple, making them favored in terms of weight and production cost. Therefore, induction heaters are more appropriate than PTC heaters for use as the heating system of electric vehicles (EVs). In the design of an induction heater, maximizing the inductance size is one of the most important elements. The capacity of the capacitor connected to the circuit for LC resonance can be reduced by increasing the inductance generated by the induction heater. The capacity of the capacitor is proportional to the price and weight. An optimal design for maximizing the inductance of the induction heater was made using the finite element method (FEM) and the Taguchi method. In addition, the inductance value obtained from the FEM simulation was compared with the measured value
Series coupled magnetic gear design for high torque density at high gear ratio
1Chosun university, Gwangju, Korea, Republic of (South Korea); 2Sungkyunkwan University, Suwon, Korea, Republic of (South Korea)
Regardless of gear ratio, if gearboxes have the same torque density, the higher the gear ratio, the higher the overall system torque density of the geared motor. Coaxial magnetic gears (CMGs) are expected to improve the overall system torque density because they have a high torque density (exceeding 100kNm/m3). However, since the gear ratio and the torque density are inversely proportional to the conventional CMG, it is confirmed that the CMG is not suitable for the gear box. Therefore, in this paper, we propose a new structure of CMG and improve the torque density more than 2 times compared with the conventional CMG. Also, it shows the effective 3D numerical analysis of the CMG, thereby improving the analysis error and the design completeness of the proposed model.
Worst Case Scenario Robust Optimization Utilizing Adaptive Dynamic Taylor Kriging surrogate Model
1Shenyang University of Technology, China, People's Republic of; 2Chungbuk National University, Korea
For the robust optimal design of electromagnetic problems under uncertainties, the robustness evaluation is the critical problem. This paper presents a surrogate model based worstcasescenario optimization algorithm, where the adaptive dynamic Taylor Kriging is incorporated to construct a higher accurate surrogate model. Finally, an improved differential evolution algorithm, DE/λ-best/1/bin, is adopted to search for the global robust optimal solution.
Design Optimization of Ironless Permanent Magnet Synchronous Linear Motor Using Co-Kriging Surrogate Model
1Shenyang University of Technology, China, People's Republic of; 2Kwangwon National University, Korea; 3Chungbuk National University, Korea
A numerically more efficient and accurate co-Kriging model is developed, and incorporated into particle swarm optimization to be applied to optimal design of electromagnetic devices. The sampling points in the co-Kriging consist of a few expensive data and many cheap data to save the computational efforts while increasing modeling accuracy. The proposed algorithm is validated through the TEAM 25, and applied to an optimal design of ironless permanent magnet synchronous linear motor.
Multi-Objective T.E.A.M. Benchmark Problem with Gaussian Regressor
University of West Bohemia, Czech Republic
A novel solution of the multi-objective T.E.A.M. benchmark problem is proposed and compared with results obtained by other approaches. The solution based on algorithm NSGA II combined with the Gaussian regression process makes it possible to significantly reduce the number of evaluations of the fitness function and shorten the computation time.
Optimization Design for Electromagnetic Devices Using an Enhanced Salp Swarm Algorithm
1Department of Electrical Engineering, University of Hafr Al Batin, Hafr Al Batin, KSA; 2Institut Polytechnique des Sciences Avancées, France
An Enhanced version of the Salp Swarm Algorithm (SSA) is proposed in this paper for the optimization design of electromagnetic devices. The basic steps of the SSA as well as the proposed modifications on the SAA are discussed. Furthermore, the performance of the proposed algorithm is tested on TEAM Workshop Problem 22 and the loudspeaker design problem
Improved Performance of a Transmission Line Based on a Hybrid Evolutionary Multi-Objective Optimization
1Federal University of Minas Gerais, Brazil; 2Federal Center of Technological Education of Minas Gerais, Brazil
The transmission of electric energy is a fundamental factor for the development of a country. Therefore, technologies applied in the electric power system is so important to provide energy for consumers, establishing a favorable environment for economic growth and social improvements. The main objective of this paper is the development of a mathematic model in order to optimize the performance of a high-power overhead transmission line (TL) by the determination of the optimal conductor bundles geometric configuration. A hybrid evolutionary multi-objective optimization algorithm is applied to address this optimization problem based on the non-dominated sorting genetic algorithm II (NSGA-II) framework and on the differential evolution (DE) recombination. This paper presents results for a three-phase TL of 500 kV, with one circuit of three conductor per phase and two ground wire.
_A Posteriori_ Strategy to Identify Robust Solutions in the Many-Objective Design Optimization of an Axial-Flux Permanent Magnet Synchronous Generator
Federal University of Minas Gerais, Brazil
Parametric uncertainties inherently exist in most real-world equipment design. In a generator design optimization process, parametric uncertainties pose a very important issue that directly affects its efficiency. In this work, after the use of a NSGA-III algorithm to optimize the design of an Axial-Flux Permanent Magnet Synchronous Generator subjected to parametric uncertainties, an a posteriori strategy is applied to identify robust solutions with low parametric sensitivity and high nominal efficiency to be implemented in practice. This methodology was applied with the aim to select the best robust optimum solution from the Pareto set in a many-objective environment.
Model-Based Source Optimisation for Eddy-Current Thermography in Planar Specimens Using Meta-Modelling
1CEA LIST; 2Laboratoire des Signaux et Systèmes, UMR8506, CNRS-CentraleSupélec-Univ. Paris Sud, Université Paris-Saclay
The design and optimization of the eddy current source (coil and current signal) in induction thermography applications is not a trivial task due to the increased number of tuning parameters and the multi-physics nature of the problem. Numerical simulation can be a valuable aid for revealing the parameters with the highest impact to the inspection performance and consequently optimizing the excitation configuration. However, consideration of all possible parameters combinations can lead to excessive computational times. To overcome this problem, meta-modelling approaches in conjunction with sophisticated interpolators can be used, which allow nearly real-time evaluations in the optimization process. In this work, the optimisation problem for a two-dimensional inspection scenario will be presented together with the corresponding sensitivity study of the most influential parameters be resorting to a meta-modelling strategy.
Continuum Sensitivity Analysis for Electrode Shape Optimization in Electrostatic System with State Variable Constraint
SungKyunKwan University, Korea, Republic of (South Korea)
This paper proposes an electrode shape optimization in an electrostatic system with state variable constraints. The continuum sensitivity formula for the electrostatic system is used to find the extremum of objective functions with state variable constraint. We use the gradient projection method and restoration process in order to consider the geometric and state variable constraints. The geometric change of the design parameter is determined by the velocity field calculated from the continuum sensitivity analysis and is expressed by the level set method. The application model is tested to show the feasibility and utility of the proposed method.
Optimal Design of a Notched Circular Patch Antenna for L1 GPS and Iridium Bands
1Department of Electronic and Computer Engineering, Brunel University, Uxbridge, UB8 3PH, U.K.; 2Department of Engineering & Technology, University of Huddersfield, Huddersfield HD1 3DH, U.K.; 3Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece; 4Hellenic Telecommunications Organization S.A., Maroussi 15122, Greece
In this paper an attempt to optimize the geometry of a patch antenna with notches is made using 3D electromagnetic simulation and the Invasive Weed Optimization algorithm (IWO). IWO is a very powerful tool for optimizing antenna geometries and electromagnetic designs in general. The goal is to generate an antenna, which is characterized by a small form factor, ease of fabrication and an appropriate geometry for operation at the L1 GPS band (1.57 GHz) and at the Iridium band (1.62 GHz). Since the antenna is designed for satellite communications, its radiation characteristics should consist of high realized gain, low return loss and small axial ratio for the frequencies of operation. IWO achieves satisfactory results with a relatively small number of evaluations.
Numerical toolbox used for the magnetic design of the PUMA Penning trap
1Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Germany; 2Technische Universität Darmstadt, Institut für Kernphysik, Germany
PUMA (antiProton Unstable Matter Annihilation) is a nuclear physics project aiming at probing the structure of radioactive nuclei at CERN by use of low-energy antiprotons. The keystone of PUMA is a transportable Penning trap for antiprotons. From an electromagnetic point of view, this apparatus is able to confine charged particles by exploiting an homogeneous magnetic field and a quadrupole electric field. This work describes and discusses the methodology followed for the design of the 4T magnet of the PUMA trap.
Shape optimization of quadrupole resonator for the RF characterization of superconductors
1University of Rostock, Germany; 2DESY & Universit ̈at Hamburg; 3Helmholtz-Zentrum Berlin
This paper discusses the application of the shape derivative for the multi-objective optimization of a quadrupole resonator designed for characterization of superconducting materials. For this purpose, the parameterized model of the device is simulated using a Finite Element (FE) approach to solve an eigenvalue problem resulting from the Helmholtz equation.
Furthermore, to assess the impact of the particular geometrical parameters onto objective functions, the variance-based sensitivity analysis is proposed. Thereby, the velocity method is used to derive a shape sensitivity of objective functions. Finally, we show the efficient approximation of the Pareto front using a gradient based on the multi-objective steepest decent algorithm for a three dimensional (3D) model of the quadrupole resonator.
Optimal Design of Bitter Magnet Cooling Channels Based on Hybrid Algorithm Using Shape and Topology Optimization
Seoul National University, Korea, Republic of (South Korea)
Optimal design of cooling channels of a water-cooled Bitter magnet is important to limit peak magnetic stress of the magnet as well as to enhance its cooling capacity. Key design parameters include topology of the cooling channels and their arrangement along the radius and the perimeter on the Bitter plates. This paper presents an optimal design of a 10 T Bitter magnet cooling channel configuration using the HASTO method, i.e., a hybrid algorithm using shape and topology optimization. Magneto-static and structural finite element analyses (FEAs) are adopted to calculate electromagnetic fields and consequent magnetic stress by the Lorentz force, while an analytic approach is used to perform thermal analysis of the magnet in consideration of the cooling channel configuration and the water coolant pressure drop. Results from our optimal design are compared with those of a previously designed 10 T Bitter magnet. Improvement on electromagnetic, mechanical, and thermal performances of the magnet after our optimization is discussed to together with some practical issues on implementation of the newly designed magnet.
Design and Optimization of the Dual-PM Machine with a Novel Model
The Hong Kong Polytechnic University, Hong Kong S.A.R. (China)
The optimal configuration of the stator for dual-PM machine (DPMM) is investigated in this paper. The slot and pole combinations are investigated firstly. The effect of the location of PMs at different position of stator is studied in terms of output torque, torque ripple, and power factor. It is found that the PMs at stator slots contribute more to the output torque than PMs on stator teeth. The stator PMs will bring extra cogging torque to the machine compared with rotor-PM machine. The power factor of dual-PM machine with proper stator slots and rotor poles combinations can reach near 0.9 which is relatively higher compared with both rotor-PM machine and stator-PM machine.
Design of Stator-PM Machine with Double Winding for Hybrid AC/DC Microgrid Application
The Hong Kong Polytechnic University, Hong Kong S.A.R. (China)
A novel stator-PM machine with two sets of armature winding is proposed in this paper. The proposed machine can be seen as a combination of a double salient machine and a stator-PM machine. For the double salient machine, since half of the stator teeth is open through the permanent magnets on the surface of stator teeth, a double salient machine with 12 stator slots and 10 poles is obtained and concentrated winding can be adopted. The key of the design is to employ two sets of the armature winding to utilize the abundant harmonics exist in the airgap brought by the flux modulation effect. The performances of the proposed machine will be analyzed through the time-stepping finite-element method.
Simplified Prediction of Cogging Torque Considering Uneven Magnetized Permanent Magnet and Teeth Curvature
Incheon National University, Korea, Republic of (South Korea)
This paper proposes a simplified prediction of cogging torque considering uneven magnetized permanent magnet (UPM) and teeth curvature. First, an impact of UPM on cogging torque is analyzed. Second, an analytical method of cogging torque by teeth curvature is investigated. Finally, a simplified deduction for cogging torque with teeth curvature in a UPM motor is suggested, comparing with the analysis through a finite element method.
Robust Optimization of a Permanent Magnet Synchronous Machine Considering Uncertain Driving Cycles
1Institut Theorie Elektromagnetischer Felder, Technische Universität Darmstadt, Darmstadt, Germany; 2Graduate School of Computational Engineering, Technische Universität Darmstadt, Darmstadt, Germany
This work focusses on the optimization of a permanent magnet (PM) synchronous machine while considering uncertainties in the PM geometry and the driving cycle. The aim is to reduce the PM volume such that the energy efficiency over the driving cycle and the machine's maximal torque are maintained. The driving cycle under consideration is the European urban driving cycle. Its uncertainties are linked to changing road conditions and to different driving styles. Using sequential quadratic programing a robust optimization is performed in which the stochastic quantities are determined by stochastic collocation. The obtained optima are tested for robustness. It is found that the uncertainties in the driving cycle significantly influence the optimal size of the PMs.
Topology Optimization of Electric Motor Using Gaussian Basis Functions for Reduction of Mechanical Vibration
Hokkaido University, Japan
This paper proposes a topology optimization method of an electric motor aiming at reduction of mechanical vibration in the stator caused by the electromagnetic force. In proposed method, the rotor structure is represented by the Gaussian basis functions for the topology optimization. The rotor structure is optimized so that displacement in the stator, which is computed by the mode-superposition method based on the finite element method, is suppressed in a wide frequency range.