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Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

This paper aims to introduce an original application of the corrected response surface method (CRSM) in the context of the optimal design of a permanent magnet synchronous machine used as an integrated starter generator. This method makes it possible to carry out this design in a very efficient manner, in comparison with conventional optimization approaches.

The search for optimal conditions is achieved by the joint use of two multi-physics models of the machine to be optimized. The former models most finely the physical functioning of the machine; it is called “fine model”. The second model describes the same physical phenomena as the fine model but must be much quicker to evaluate. Thus, to minimize its evaluation time, it is necessary to simplify it considerably. It is called “coarse model”. The lightness of the coarse model allows it to be used intensively by conventional optimization algorithms. On the other hand, the fine reference model makes it possible to recalibrate the results obtained from the coarse model at any instant, and mainly at the end of each classical optimization. The difference in definition between fine and coarse models implies that these two models do not give the same output values for the same input configuration. The approach described in this study proposes to correct the values of the coarse model outputs by constructing an adjustment (correcting) response surface. This gives the name to this method. It then becomes possible to have the entire load of the optimization carried over to the coarse model adjusted by the addition of this correction response surface.

The application of this method shows satisfactory results, in particular in comparison with those obtained with a traditional optimization approach based on a single (fine) model. It thus appears that the approach by CRSM makes it possible to converge much more quickly toward the optimal configurations. Also, the use of response surfaces for optimization makes it possible to capitalize the modeling data, thus making it possible to reuse them, if necessary, for subsequent optimal design studies. Numerous tests show that this approach is relatively robust to the variations of many important functioning parameters.

The CRSM technique is an indirect multi-model optimization method. This paper presents the application of this relatively undeveloped optimization approach, combining the features and benefits of (Indirect) efficient global optimization techniques and (multi-model) space mapping methods.

The relative motion between the inductor and the work‐piece to be heated, the magnetic non‐linearity and the dependence of physical properties on temperature are considered in the numerical simulations of continuous transverse flux induction heating of metallic sheets and scanning type induction heating of billets. Using the translating air‐gap technique, the transient and the steady state electromagnetic and thermal fields are evaluated.

A general approach to the formation of magnetic equivalent circuit describing the magnetic process inside the electric machines is proposed. This formation is based on tooth contour method. Coupling with external and internal electric circuits of electric machines is emphasized as well as mechanical coupling with load. The resulting model allows the simulation of electromechanical converter, but with the number of element being fewer by several orders compared to traditional finite element models. Non‐linearity such as saturation or electronic switch is taken into account. General equations for the magnetic fields and electric circuits of electrical machines are written using a common basis – the nodal potential method. The whole process is illustrated on the simulation of a claw poles alternator compared with measurements.

The purpose of this paper is to present an optimal sizing methodology. It is applied to a foil-coil powder core power inductor used in new generation inverters designed for hybrid and full-electric vehicles. The methodology includes a preliminary analytical calculation and a numerical optimization aimed at minimizing the component size.

Unlike bulk magnetic alloys or ferrites, the magnetic non-linearity of powder materials cannot be neglected in the analytical calculation. This non-linearity requires the use of an iterative calculation to search the set of parameters for which the target inductance value and the minimum volume are simultaneously reached. The numerical optimization process is based on 2D Finite Element (FE) analysis carried out with FEMM software tool and a simplex-type algorithm run in Scilab software. These two freewares are coupled using the scifemm.sci script which is included in the FEMM distribution.

The association of analytical and FE approaches provides a relevant and quick sizing methodology. It was successfully applied to size a new power inductor.

The strong non-linearity of the powder material is correctly taken into account in the analytical model thanks to an iterative calculation process. Thus, the preliminary analytical solution is quite relevant. Consequently, a local FE-based optimization is enough to find the optimal solution close by the analytical one. No global optimization is required. A local optimum is sufficient.

The purpose of this paper is to provide a comprehensive analysis of different material models when observing the magnetisation dynamics and power losses in non-oriented soft magnetic steel sheets (SMSSs).

During the analysis four different magnetic material models were used for describing the static material characteristics, which characterised the materials’ magnetisation behaviour with increasing accuracies: linear material model, piecewise linear material model, non-linear H(B) characteristic and the static hysteresis material model proposed by Tellinen. The described material models were implemented within a parametric magneto-dynamic model (PMD) of SMSSs, where the dynamic responses as well as power loss calculations from the obtained models were analysed.

The momentous influences of various levels of detail on the calculation of dynamic variables and power losses inside SMSS with non-uniform magnetic fields were elaborated, where various static material characteristic models were evaluated, ranging from linear to hysteretic constitutive relationships.

The resulting PMD model using different static models was analysed over a frequency range from quasi-static to f=1,000 Hz for different levels of magnetic flux density up to B _max=1.5 T.

The presented analysis provides fundamental insight when calculating dynamic electromagnetic variables and power losses inside non-linear SMSSs, which is instrumental when selecting an adequate model for a specific application.

This paper provides closer insight on the way non-linearity, magnetic saturation and hysteresis affect the energy loss and magnetisation dynamics in SMSSs through the level of detail in the used material model. The strongly coupled model addresses both induced eddy currents and the ferromagnetic materials’ magnetisation behaviour simultaneously using varying levels of detail so that the interplay between skin effect (i.e. eddy currents) across laminations and hysteresis can be resolved accurately. Therewith, adequate models for specific applications can be selected.

The paper presents a method of creating electrical equivalent diagrams of magnetic circuits. The method is based on bond‐graph techniques, using flux derivative as flow variable. Couplings between magnetic and electric part of the system are represented by gyrators. Simple models of magnetic branches, including non‐linear effects due to saturation, hysteresis and eddy currents, are presented. These models can be easily combined into magnetic circuit models, which can be transformed into dual electric equivalent circuit. Various equivalent circuits of transformers are discussed. The proposed models are simple and particularly useful for system‐level simulation of power electronic and motion control systems with magnetic elements. These models can be easily developed if needed. Theoretical considerations are illustrated by examples of digital simulation and experimental results.

To study the magnetic shielding and the losses of non‐linear, hysteretic multilayered shields by using fast to evaluate analytical expressions.

In order to evaluate the shield in the frequency domain, the non‐linear shield is divided into a sufficient number of piecewise linear sublayers. Each sublayer has a permeability that is constant (space independent) and complex (to model hysteresis). This expression for the permeability is found from the Preisach model by a Fourier transform. Once H is known in the entire shield, analytical expressions calculate the eddy current losses and hysteresis losses in the material. The validity of the analytical expressions is verified by numerical experiments.

In the Rayleigh region, the shielding factor of perfectly linear material is better than the one of non‐linear metal sheets, but also the eddy current losses are higher. The results of the optimization show that steel is only a useful shielding material at low frequencies.

The analytical method is valid for infinitely long shields and for weak imposed fields in the Rayleigh region.

As the analytical expressions can be evaluated very fast (in comparison with slow finite elements models), many magnetic shields can be compared in parametric studies.

Analytical expressions exist for the shielding factor and the losses of linear materials. In this paper, the method is extended for non‐linear hysteretic materials. The effects of several parameters (material parameters, incident fields parameters) on the shielding and the losses are shown.

Introduces papers from this area of expertise from the ISEF 1999 Proceedings. States the goal herein is one of identifying devices or systems able to provide prescribed performance. Notes that 18 papers from the Symposium are grouped in the area of automated optimal design. Describes the main challenges that condition computational electromagnetism’s future development. Concludes by itemizing the range of applications from small activators to optimization of induction heating systems in this third chapter.

To study effects in the Fourier spectra of cage motor phase currents due to saturation of the main magnetic circuit by the fundamental MMF harmonic.

An idea of an equivalent magnetizing current is applied, which allows to consider an influence of all currents of stator and rotor windings on the main magnetic circuit permeability. The energy base approach is used to write machine equations and the harmonic balance method is used to determine the Fourier spectra of currents.

It has been shown that the saturation generate additional harmonics in phase currents, which are shifted by 100 Hz from the so called slot harmonics.

A model and a solving method allows to predict all slot harmonics quantitatively, but qualitative difference of the Fourier spectra to measurement still exist.

More precise prediction of the Fourier spectra of stator phase currents for on‐line diagnostic systems.

A circuit model of a cage motor accounting for saturation by slot harmonics and an algorithm for determination of additional components in the phase current Fourier spectra.