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This paper presents the calculation of pulsating losses in the air‐gap at laminated stator and rotor pole surface of the synchronous reluctance motor (SRM). The calculation is based on change of magnetic flux density in the air‐gap due to the permeance variation on both stator and rotor inner surfaces. These changes are calculated using finite element method. The equation for calculation of the pulsating losses is carried out using reduced Helmholtz's differential equation and the 1st Maxwell equation. Finally, the values measured and calculated are compared to each other.

The purpose of this paper is to derive the geometry‐based equations for inductances which are used in circuit theory analysis of synchronous reluctance motor (SRM). Transient and steady state performance analyze of SRM by using the 2D time‐stepping finite‐element method (FEM).

The analytical approach is used to obtain the equations which describe geometry dependent magnetizing inductances of SRM. Transient and steady state performance of the SRM is analyzed by using the 2D time‐stepping FEM. The external electric circuit connected with the finite‐element model of the SRM geometry allows the study of almost any of the electric and magnetic properties of the machine. Presented SRM model is also connected to the external mechanical loads (friction, rotor inertia and load torque). The use of different materials for the magnetic‐pole part of the rotor and for flux barriers was analyzed. The flux barriers in the first SRM rotor were filled with a pure massive electrically conductive ferromagnetic with a proper B‐H curve, whereas the rotor magnetic segments were made of non‐conductive electric steel described with its B‐H curve. The conductive barriers with their end rings form a squirrel cage and allow SRM to start on‐line. The flux barriers of the second SRM rotor were made of aluminum but between the second and third flux barrier a massive electrically‐conductive ferromagnetic was inserted which during starting‐up acted as a part of the squirrel cage. All of the flux barriers of the third SRM rotor were made of electrically‐conductive aluminum with iron parts axially laminated. The finite‐element SRM models coupled with an electric circuit is also used to evaluate the motor performance at various asynchronous speeds.

Analytical geometry‐dependant equations for the d‐ and q‐axis SRM inductances are derived. On the basis of the proposed 2D time‐stepping finite‐element analysis, the start‐up performance for the SRM rotor design using different materials is established. The torque distribution as a function of time at any of the observed asynchronous speeds is not smooth and uniform. It consists of the stator‐to‐rotor tooth pulsating torque, and the synchronous and asynchronous component.

The main disadvantage of analytical geometry‐dependant equations for the d‐ and q‐axis SRM inductances is the linearization of any of the ferromagnetic parts.

On the basis of the proposed 2D time‐stepping finite‐element analysis, the start‐up performance, asynchronous run and synchronous torque characteristics for the SRM rotor design using different materials are established.

The value of the paper is the closed view about happenings in rotor flux barriers of SRM, mostly regarding the time distribution of induced currents in the rotor flux barriers. On the base of 2D time‐stepping FEM, the use of different materials for the magnetic‐pole part of the rotor and for flux barriers was analyzed.

To analyze the Jiles and Atherton hysteresis model used for hysteresis losses estimation in soft magnetic composite (SMC) material.

The Jiles and Atherton hysteresis model parameters are optimized with genetic algorithms (GAs) according to measured symmetric hysteresis loop of soft magnetic composite material. To overcome the uncertainty, finding the best‐optimized parameters in a wide predefined searching area is done with the proposed new approach. These parameters are then used to calculate the hysteresis losses for the modeled hysteresis. The asymmetric hysteresis loops are also investigated.

The classical GAs are good optimization methods when a pre‐defined possible set of solutions is known. If no assumption on solutions is present and a wide searching area range for parameter estimation is selected then the use of the new approach with nested GAs gives good results for symmetric hysteresis loops and further for the estimation of hysteresis losses.

The use of the Jiles and Atherton hysteresis model for asymmetric hysteresis must be explored further. Only one set of optimized Jiles and Atherton hysteresis model parameters used for estimation of hysteresis losses gives good results for only symmetric hysteresis loops. These parameters have limitations for asymmetric hysteresis loops.

Nested GAs are a useful method for optimization when a wide searching area is used.

The originality of the paper is in the establishment of nested GAs and their application in Jiles and Atherton hysteresis model parameters optimization. Also, original is the use of the Jiles and Atherton hysteresis model for hysteresis loop description of soft‐magnetic composite material.

This study aims to calculate eddy current losses in permanent magnets of BLDC machine in the generator mode of operation with no‐load.

Stator slot openings and special design of the stator poles cause changes in the magnetic flux density changes in permanent magnets. The stator windings are not connected to an outer source and no currents flow in them. The induced eddy currents in permanent magnets are dependent solely on the stator geometry. Analytical approach to calculate the eddy current density distribution in permanent magnets is based on known distribution of magnetic flux density in the air‐gap of BLDC. The magnetic flux density distribution is obtained from magneto‐static finite element model of BLDC. For verification of analytical approach the eddy current density distribution in permanent magnets is also calculated by magneto‐transient finite element model of BLDC.

The eddy current losses in PM obtained with the FEM indicate additional heating of the BLDC machine at high rotational speeds even when it operates at no load. When some special stator designs (the side of the air gap) are needed, the losses in PMs and their heating increase.

To get more precise results, the proposed analytical method for eddy current losses calculation in PM should be further analyzed. More geometric parameters of the BLDC design should be introduced to analytical formulations, especially those which affect variations in reluctance.

When some special stator designs (the side of the air gap) are needed, the losses in PMs should be observed. This is particularly recommended at higher rotation velocities. Any kind of magnetic flux density change induces eddy currents and together with them also power losses. These losses give rise to additional heating of PM. With this, the temperature‐dependent working characteristic of PM (second quadrant of the B‐H curve) moves toward the coordinate origin point. The overall machine performance is reduced. The presented work gives the view about happenings in permanent magnets regarding induced eddy current losses. It is a useful tool for fast estimation and reduction of eddy current losses in PM due to stator geometry.

The value of the paper is the closed view about happenings in permanent magnets regarding induced eddy currents and the calculation of eddy current losses in rotor permanent magnets of BLDC due to stator design. The originality is in the analytical approach to calculate the eddy current losses based only on known magneto‐static flux density distribution in air‐gap of BLDC.

The paper deals with the calculation and reduction of torque pulsation in synchronous reluctance motors (SRM). The analysis is based on finite element modeling and proposes a method of dynamic torque characteristic calculation. The mutual connection between static and dynamic torque characteristic is also established. Several aspects for reduction of torque pulsation are demonstrated and applied with success.

The purpose of this paper is the investigation of eddy currents induced in the axial‐flux permanent‐magnet machine housing by the leakage flux and the introduction of permanent magnets in the steady‐state AC finite‐element analysis and coupling their effects with the transient thermal analysis.

The proposed approach is based on the finite‐element method as well as on using the basic analytical equations. The approach was first applied in the magneto transient analyses. Because of the different physical transient‐time constants, the steady‐state AC analysis coupled with transient thermal should be used.

The permanent magnets in the steady‐state AC analysis coupled with the transient thermal analysis can be simulated by coils with an imposed current of a frequency depending on the number of pole pairs and rotation speed. Using any of the electrically conductive materials for the axial‐flux inner slotless stator permanent‐magnet machine housing should be avoided.

The leakage flux induced by permanent magnets and spreading into the axial‐flux permanent‐machine housing is first defined by using the magneto‐transient finite‐element analysis and further used in the steady‐state AC analysis coupled with the transient thermal analyses, all in 3D. Based on the results of these analyses, the temperature distribution in entire machine is calculated and compared with the measurement results.

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.