F. Gillon

Three-Level Output Space Mapping Strategy for Electromagnetic Design Optimization

Optimal design with finite element model is often expensive in terms of computation time. The output space mapping technique allows benefiting both the rapidity of the analytical model and the accuracy of the finite element model. In this paper, a three-level output space-mapping technique is proposed to reduce the computation time. Three models having a different granularity and describing the same device are used jointly within the optimization process. Proposed strategy is applied for solving the optimal design problems of two electromagnetic devices. Results show that three-level output space mapping strategy allows saving a substantial computation time compared to the classical two-level output space-mapping.

A Parallel Multiobjective Efficient Global Optimization: The Finite Element Method in Optimal Design and Model Development

Conceiving electromagnetic devices using finite element modeling tools is a complex task and also time-costly. The Efficient Global Optimization method, based on the progressive construction of surrogate models, is studied. The method uses Kriging models and allows for multiobjective optimization. An original infill criterion, combining the surrogate models and an estimate of their error is proposed. Moreover, two techniques for the calculi distribution, adapted to the algorithm, are tested on an eight-core machine. An advantage of the method consists in its capability of providing sufficiently accurate models for each objective and constraint function around the obtained Pareto front. The SMES device of the TEAM problem 22 is used as benchmark.

Design of permanent magnet synchronous machine in order to reduce noise under multi-physic contraints

This paper describes the modeling of a permanent magnet synchronous machine by lumped models. Several fields of physics, such as electromagnetics, thermics, mechanics and acoustics are necessary for designing electrical machines. The aim of this study is to build a design model of a permanent magnet synchronous machine for traction applications which takes into account all these different physical aspects. Magnetic, electrical, electronic and thermal parts are represented by lumped models, whereas vibro-acoustic and mechanical parts are represented by analytical models. Simulation results are presented and compared with the finite element method and experiments. These fast and entirely parameterized, lumped models make it possible to couple the software with optimization tools. Some optimization results are discussed here.

Techno-economic optimization of induction machines: An industrial application

Current economic situation force manufacturers to find the new ways of designing electrical machines. In order to succeed in competitive market, industry has to create new approaches of finding the solutions which will satisfy customers requirements. Task of determining this set of optimal configurations must be done in the least possible time frame. This problem is becoming more complex when the required electrical machine is not in the standard range of configurations and so the price of the solution cannot be determined with high precision. In this article we propose an example of industrial application which assists in defining the set of optimal configurations of induction machine where the criterions of optimality are the efficiency and total cost of manufacturing.

Multi‐objective optimization of a linear induction motor using 3D FEM

Purpose – The purpose of this paper is to present a low evaluation budget optimization strategy for expensive simulation models, such as 3D finite element models.Design/methodology/approach – A 3D finite element electromagnetic model and a thermal model are developed and coupled in order to simulate the linear induction motor (LIM) to be conceived. Using the 3D finite element coupling model as a simulation model, a multi‐objective optimization with a progressive improvement of a surrogate model is proposed. The proposed surrogate model is progressively improved using an infill set selection strategy which is well‐suited for the parallel evaluation of the 3D finite element coupling model on an eight‐core machine, with a maximum of four models running in parallel.Findings – The proposed strategy allows for a significant gain of optimization time. The 3D Pareto front composed of the finite element model evaluation results is obtained, which provides the designer with a set of optimal trade‐off solutions for ...

Comparison between efficient global optimization and output space mapping technique

The optimization of electromagnetic devices by direct use of finite element models is computationally expensive. This paper presents two effective surrogate-assisted optimization algorithms: Output Space Mapping and Efficient Global Optimization which are employed with regard to a minimum number of finite element model evaluations. A parallel between the two algorithms is made through a single phase safety isolating transformer optimization problem using 3D finite element models.

Comparison of Efficient Global Optimization and Output Space Mapping on the Biobjective Optimization of a Safety Isolating Transformer

The optimal design of electromagnetic devices needs to address two particular aspects: 1) the use of accurate tools and 2) the limited time budget affected to this task. In order to respond to these issues, two low evaluation budget multiobjective optimization techniques-efficient global optimization (EGO) and output space mapping (OSM)-are investigated in this paper with regard to a biobjective optimization benchmark. The device to be optimally sized is a low-voltage safety isolating transformer, represented through two levels of modeling: 1) coarse (analytical model) and 2) fine (numerical 3-D FEM). The biobjective character of the problem is accounted for by OSM through an epsilon-constraint technique. A transformation technique is set up with EGO by considering the constraints as an additional objective function in order to handle the constraints of the initial optimization problem. The biobjective comparison of the two techniques on the transformer benchmark is discussed.

Influence of machine control strategy on electric vehicle range

An optimized control strategy for induction machines is presented and compared to classic strategies. The described method allows to optimize voltage and frequency for a steady state equivalent circuit model of three-phase induction machine. This method is applied to an electric vehicle by simulating driving cycles and calculating energy consumption. The potential gain for the optimized control strategy is discussed.

Proposal of a Kriging Output Space Mapping Technique for Electromagnetic Design Optimization

Using the finite-element model (FEM) to achieve the optimal design of electromagnetic devices is a complex and time-consuming process. Space-mapping techniques reduce computation cost by aligning two models with different granularities, namely, a coarse model and a fine model. In this paper, Kriging output space mapping (OSM), an original space-mapping technique based on adaptive nonlinear corrective projection, is proposed and compared with a conventional OSM technique. The device for optimal sizing is a five-phase linear induction motor, which is represented through two modeling levels: 1) coarse (Kriging model) and 2) fine (2-D FEM). An advantage of this new technique is its ability to provide a sufficiently accurate model for each objective and constraint function and make the coarse model converge effectively toward the fine model.

Optimal design of a linear induction motor for subway system

Optimal design by means of finite element models is complex and time consuming. The Efficient Global Optimization (EGO) based on the progressive construction of a Kriging model used to drive the optimization problem allows for an affordable optimization time. In this paper, a linear induction motor (LIM) with double primaries for the subway system is designed, based on the validated 2D finite element model at reduced scale and the tramways needs. The optimal design problem of LIM is formulated using the rated point design approach and achieved using the EGO algorithm.