Marcin Lefik

Rotor end effects on FEM-based flux mapping of synchronous reluctance motors

The paper deals with the accurate flux map modeling of synchronous reluctance motors through finite element analyses. By comparing 2D-FEM simulations results with measured flux maps on real machines, non-negligible discrepancies were initially observed, in particular under heavy saturation and cross-saturation conditions. Conversely, the 3D FEM-based flux mapping offers more accurate estimations of the aforementioned linked flux characteristics, and gives evidence of 3D end effects being also a function of the relative positioning between the rotor and the stator magneto-motive force waveforms. The paper investigates such three-dimensional end effects for different rotor geometries and winding structures, utilizing 2D and 3D FEM analysis in comparison to experimental data.

Stator Lamination Geometry Influence on the Building Factor of Synchronous Reluctance Motor Cores

The study investigates the influence of the lamination geometry on the building factor of stator magnetic cores, quantifying by experiments the influence of the punching and the annealing process. The research and the experimental activity are focused on small-fractional-power synchronous reluctance motors, where the effect of the punching process is expected to be very impacting, not only for the stator iron losses increase, but also because the current magnetizing component is dominant in the total input current. However, the obtained results are particularly interesting for any fractional and low power electric machines, whose cores are built with punched or laser-cut laminations.

Influence of Geometry and Assembly Processes on the Building Factor of the Stator Core of the Synchronous Reluctance Motor

This paper deals with the results of measurements, calculations, and computer simulations, leading to the determination of the stator cores building factor (BF) of the fractional power synchronous reluctance motor (350 W). In the process of calculation, the authors indicated the part of the BF factor resulting from the punching process, the geometry of the stator core, and the fabrication process carried out during manufacture of the core. The obtained results indicate that for the analyzed core, the BF factor component resulting from the punching is greater than the sum of the components coming from clamping and pressing the core into the housing. The factor component dependent on geometry is less important. The data necessary for the finite-element method modeling were obtained from the modified SST system, whose idea has been described in detail.

Comparison of the fractional power LSSR motor with cores made of various magnetic materials

Core optimization, realization of new core shapes and powering the motor at high frequency are some of the reasons to use new materials, those limit the core loss and/or have quasi-isotropic properties in any magnetization direction. In addition, commonly used punching of laminations, causes degradation of a core portions, impairing operating parameters of the motor. In this case, a very good solution may be the use of soft magnetic composite (SMC) materials. The authors deal with the impact of the SMC materials utilization on the motor parameters.

Post-annealing behaviors of small-size synchronous reluctance motors

The paper reports the experimental results of a vast test campaign conducted on synchronous reluctance motors of fractional power. These motors have relatively small geometric dimensions and it is important to evaluate the negative effects of lamination punching. Two twin 550 W motor prototypes have been produced, one with annealed magnetic cores. By means of an experimental-based comparison, the usefulness of the annealing thermal process on the final motor performance is discussed. Finally, to further prove the possibility to correctly account for the punching process in numerical models, the obtained measurement results have been compared with finite element method simulations, getting a good agreement.

Numerical modelling of a flux-barrier SynchRel motor including punching effect

Purpose Estimating the punching process’s impact on the operating parameters of an electrical motor is a special problem especially in the case of fractional power motors. The purpose of this paper is to discuss a method of numerical modelling that is useful for this case. Design/methodology/approach The proposed multi-physical FEM approach is based on using professional software in the process of modelling and determining the operating parameters of a low power motor. The basic elements of the approach are built FEM models for which the parameters characterising the damaged portions of the magnetic material were determined. The material properties of this zone were determined both by measurement and by a new analytical approach described in this paper. Findings The paper formulates the impact of punching on the operating parameters of a low power motor. Moreover, it formulates the analytical algorithm for the estimation of properties of material in damaged zones. Research limitations/implications Experimental verification will still be needed to check the model’s accuracy and applicability to various magnetic materials. Practical implications The paper provides an easy approach enabling the calculation of motor operating parameters and a simple and useful algorithm to estimate magnetic material properties in the damaged zone. Originality/value The analytical algorithm, as presented here, in conjunction with the measurement results is useful and applicable to estimating the magnetic material properties, which form the basis for accurate FEM calculation.

Comparison of the fractional power motor with cores made of various magnetic materials

Abstract The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite), reduce the core loss and/or provide quasi-isotropic core’s properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

Three-dimensional computer models of electrospinning systems

Abstract Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.

Comparative study of electrospinning systems using 3-D computer models

This paper presents an overview of the different solutions of electrospinning systems. 3D parameterized numerical models for these systems were prepared too. The 3D models allows to analyze the distribution of the electric field. In addition, examples of calculations for the analyzed systems in the form of electric field quantities distributions are also shown. In this paper the authors used COMSOL Multiphysics — multipurpose software platform for simulating physics-based problems.

Analysis of the impact of the design of HT machines on the cogging torque and losses in permanent magnets

The paper discusses a methodology for assessing computationally the effects of using different materials for magnetic wedges and applying magnet segmentation on the power losses and performance of permanent magnet machines operating at high temperatures. Time stepping finite element simulation in 2D and 3D is employed to obtain field and current distributions, power losses and derive torque ripples under various configurations. Potential consequences on mechanical vibration and local overheating are considered.