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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.

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical fields. Looks at the coupling of fields in a device or a system as a prescribed effect. Points out that there are 12 contributions included ‐ covering magnetic levitation or induction heating, superconducting devices and possible effects to the human body due to electric impressed fields.

The interbar current of a squirrel-cage induction motor (IM) flows in the steel sheets when the secondary conductor is not insulated from the laminated steel sheets. It was reported that the interbar current loss was increased when skewing the rotor core. This paper aims to analyze a skewed IM using the three-dimensional (3D) finite element method. The effects of rotor skew on the interbar current are clarified.

In this paper, a skewed squirrel-cage IM is analyzed in three patterns of skewed angle. The calculated results were compared with each other. If all laminated steel sheets are divided by the mesh with actual thickness, the huge calculation time is required. In the method applied in the study, several steel sheets are divided by the mesh with the actual thickness and some steel sheets are assumed to be the steel lump between them to shorten the calculation time.

The paper describes that the distribution of interbar current loss when rotor is skewed is different from that when rotor is not skewed. In addition, the paper suggests that the larger the skew angle becomes, the larger the interbar current loss becomes.

In this paper, a skewed IM with the consideration of the interbar current in the laminated steel sheets was analyzed using the 3D finite element method. The influences of the rotor skew on the interbar current are clarified.

The purpose of this paper is to clarify the electrical loss of an interior permanent magnet (IPM) motor driven by the pulse‐width modulation (PWM) inverter with various carrier frequencies quantitatively.

An IPM motor driven by the PWM inverter was simulated using the three‐dimensional finite‐element method while changing various carrier frequencies of the PWM inverter. The calculated results are compared with the calculated results differing the number of permanent magnet division.

The eddy current loss in the permanent magnets decreases as the carrier frequency increases. In the case of low‐carrier frequency, the eddy current loss greatly decreases as the number of permanent magnet division increases. However, the effect of the eddy current loss decreases by the number of permanent magnet division as the carrier frequency increases.

The paper describes the electrical loss of an IPM motor driven by the PWM inverter with various carrier frequencies.

When large currents flow near steel plates in large electric machines, the eddy current loss produced in the plates causes local overheating. Therefore, not only the total loss but also the loss distribution should be analyzed accurately. The local loss distribution, however, has not been fully analyzed yet.

An algorithm for simultaneous solution of equations describing transient 3D magnetic field coupled to the Kirchhoff’s equations and the equation of motion has been presented. The nonlinearity and anisotropy of the magnetic core have been taken into account. Numerical implementation of the algorithm is based on the finite element method. In order to solve the 3D problem a special iterative procedure, in which the 3D task is substituted with a sequence of 2D problems, has been proposed. The time‐stepping backward difference algorithm for the time‐discretization of the electric circuit equations has been applied. To determine the moving armature position, an implicit procedure, which is unconditionally stable has been proposed. For the sake of example, the calculations of dynamic operation of the E‐type electromagnetic actuator equipped with the shading coil have been performed.

The purpose of this paper is to present an original study of industrial inductors with different air-gap materials in order to reduce the vibration and noise of inductors. Acoustic comfort is an increasingly important factor at the design stage of industrial inductors associated to converters. In addition, power converters in the railway domain are more and more compact and powerful.

Experiments, simulations and test devices were used to determine the main physical phenomena that generate the undesirable audible noise. Electric and vibratory measurements (modal and operational analysis) were compared with the numerical calculations. PWM and sinusoidal supply were taken into account and different prototypes with different materials in the air-gap were built.

This study analyzes and details the origin of the electromagnetic noise due to the vertical mode, in order to reduce the vibration and noise of inductors. A detailed analysis using finite element simulation and experimental measurements of free-free mode or forced mode under electrical excitation was conducted to interpret the vibrations of the structure. In addition, in order to observe trends and the impact of magnetostriction effect, the authors propose a simplified model.

Electric and vibratory measurements (modal and operational analysis) are compared with the numerical calculations.

This paper gives a response about the origin of the noise with different experimental measurements. Changing the air-gap material is beneficial for the deflection of the inductor. However, it has been presented that, following the shape of the inductor, it is beneficial to reduce or increase the stiffness of the material depending on the column height. For a fixed Young’s modulus air-gap, a ratio Column height/air-gap thickness exists, which makes it possible to cancel the deflection.

The purpose of this paper is to develop a dynamic analysis method of a novel spherical resonant actuator. In this method, the magnetic field equation is coupled with the electric circuit equation and the motion equation with the mesh modification method using the Laplace equation applied to the rotation of the spherical actuator.

The static torque characteristics and dynamic characteristics of the spherical resonant actuator using the proposed method are clarified. The calculated results are compared with the measured ones.

The calculated static torque agrees well with the measured one. The validity of the computation using the proposed method is quantitatively clarified through the comparison with the measurement.

The paper proposes the dynamic analysis method of the complicated spherical resonant actuator using the mesh modification method by the Laplace equation.

In this paper, a new method for estimating iron loss under a distorted elliptical rotating flux is proposed.

In order to precisely analyze the iron loss of rotating machines, the iron loss under distorted rotating flux should be taken into account. However, reports of precise analysis considering measured iron loss data under rotating flux are few.

The iron loss of surface permanent magnet (SPM) motor model proposed by the investigation committee of IEE of Japan is estimated using the proposed method. The experimental examination is carried out by measuring the iron loss of the motor using a torque meter.

Examines an estimation method of iron loss of motors.

This paper aims to describe a novel 3D finite element mesh modification method for motors with the skewed rotor in detail, the method having been developed by solving the Laplace equation.

Using the mesh of the skewed squirrel‐cage induction motor created by the novel method, the torque, the bar‐current, the electrical losses and so on are analyzed by the 3D finite element method.

It was found that the torque ripple, the bar‐current ripple and the losses of the motor with the skewed rotor are smaller than those of the motor with the no‐skewed rotor. In addition, the validity of the analysis is clarified by comparing the calculated and the measured results.

The usefulness of the method is clarified by the 3D finite element analysis of a skewed squirrel‐cage induction motor.