Axially Laminated Anisotropic Rotor Research Articles

Impact of the Current Vector Angle on the Performance of a Synchronous Reluctance Motor With an Axially Laminated Anisotropic Rotor

The impact of the current vector angle on the performance of a synchronous reluctance motor (SynRM) with an axially laminated anisotropic (ALA) rotor intended for high-speed applications is studied. The paper shows that the current vector angle not only impacts on the stator winding Joule losses and iron losses, but also strongly influences eddy current losses in the rotor (when the rated torque is produced). The rotor eddy current losses are determined by the flux density harmonics produced by the stator. The air gap flux is affected both by the magnitude and angle of the current vector. However, the rotor surface harmonics are not directly related to the overall flux level (which can be quite low at a high current angle) but depend more on the values of the individual slot current linkages. Considering the dependence of rotor losses on the current vector angle, the most efficient operating point is suggested to be close to 45° or slightly larger, up to 65°, where a compromise between increasing rotor eddy current losses and winding Joule losses and decreasing stator iron losses is found. The eddy current loss distribution between the layers of an ALA rotor is analyzed in detail. With a larger current vector angle, the eddy current losses increase most in the layers close to the d-axis. This is explained by the largest current linkage in the stator slots that are in front of the layers close to the d-axis. The dependence of torque ripple on the current vector angle is also observed. An analysis of rotor and stator high-order harmonics, which determine the torque ripple, is performed.

Influence of Magnetic and Nonmagnetic Layers in an Axially Laminated Anisotropic Rotor of a High-Speed Synchronous Reluctance Motor Including Manufacturing Aspects

The impact of the thickness of the magnetic and nonmagnetic layers in an axially laminated anisotropic (ALA) rotor in a synchronous reluctance motor (SynRM) aimed at high-speed applications was studied. Considering possible manufacturing issues, the layers are desired to be thick rather than thin. At the same time, the layer thickness is related to the electromagnetic capabilities of the ALASynRM. In the study, a 12 kW ALASynRM was considered. As a reference, a 12 kW IM with a smooth solid rotor with copper end rings was used for comparison with the designed ALASynRM. The manufacturing procedures of an ALA rotor with certain materials were verified in practice. Strength tests of the samples were implemented showing the suitability of the selected materials for application in the prototype. In the electromagnetic design, the thickness of the ALA rotor layers has shown to have a significant impact on the rotor eddy current losses. The stator iron losses and the winding Joule losses also depend on the rotor design. Torque ripple is considerably affected by the thickness of the rotor layers and their position in relation to the stator slots.

축 방향 성층 이방성 동기형 릴럭턴스 전동기의 최적설계 및 유도전동기와의 특성 비교

The performance of a Synchronous Reluctance Motor (SynRM) in terms of torque and power factor depends on the two-axis inductances L<SUB>d</SUB> and L<SUB>q</SUB> of the machine. The Axially Laminated Anisotropic (ALA) rotor should be proposed in an effort to increase the L<SUB>d</SUB>/ L<SUB>q</SUB>ratio and the L<SUB>d</SUB>-L<SUB>q</SUB> difference to secure high torque density and high power factor. So, ALA rotor is suitable for high speed instruments. This paper deals with optimum design of Axially Laminated Anisotropic Synchronous Reluctance Motor (ALA-SynRM) and comparison of characteristics with induction motor. Coupled Finite Element Methodology (FEM) & Response Surface Methodology (RSM) have been used to evaluate optimum design solutions. Comparisons are given with characteristics of a same rated wattage induction motor and those of ALA-SynRM respectively.

Particle Swarm Design Optimization of ALA Rotor SynRM for Traction Applications

Particle swarm optimization (PSO) algorithm is applied to the design optimization problem of axially laminated anisotropic (ALA) rotor synchronous reluctance motor (SynRM) drive. The objective of the optimization is to maximize the developed torque while minimizing the torque ripple as well as the ohmic and core losses for traction applications. The number of flux paths, stator tooth width, and rotor flux path width define the 3-D search space for the optimization problem. An artificial intelligence modeling approach utilizing PSO and finite element-state space (FE-SS) models is used for the characterization and design optimization of a prototype ALA rotor SynRM drive for traction applications.

Design Optimization of ALA Rotor SynRM Drives Using T-AI-EM Environment

An integrated team artificial-intelligence electromagnetic (T-AI-EM) environment is developed to accurately determine the performance of synchronous reluctance motors (SynRM) with axially laminated anisotropic (ALA) rotor configurations. This identifier coupled to a Fuzzy Logic optimization model is used to predict an optimal design of the machine for any given input torque. The main objective of this optimization is to minimize the torque ripple, as well as Ohmic and core losses at a given torque-speed condition. This environment is applied for the characterization and design optimization of a prototype 100-kW, 6000-rev/min ALA Rotor SynRM drive system for traction applications. The T-AI-EM environment resulted in an optimized machine design. The simulation results were compared to measured performance data for verification

Parameters evaluation of ALA synchronous reluctance motor drives

A method to evaluate the parameters and to predict the performance characteristics of axially laminated anisotropic (ALA) rotor synchronous reluctance motor (SynRM) drive systems is presented. The method is based on the use of an iterative approach which indirectly couples a two dimensional (2D) nonlinear finite element (FE) model, which accounts for anisotropy, to a state space model describing the SynRM drive system. At the heart of this method is an inductance computation technique which is based on the use of a reluctivity tensor. The results of applying this approach to a prototype ALA rotor SynRM drive system are presented.

Effects of anisotropy on the performance characteristics of an axially laminated anisotropic-rotor synchronous reluctance motor drive system

The effects of accounting for anisotropy on the performance characteristics of axially laminated anisotropic (ALA) rotor synchronous reluctance motor (SynRM) drive systems are studied. These effects are evaluated from the simulations of a computer aided model. The model is based on the use of an iterative approach which indirectly couples a two dimensional (2D) nonlinear finite element (FE) model, which accounts for anisotropy, to a state space model describing the SynRM drive system. The simulation results are also validated by comparison to test data of a prototype ALA rotor SynRM drive system.

High-performance reluctance generator

The paper introduces the axially laminated anisotropic (ALA) rotor reluctance synchronous machine as a brushless high-performance generator. A new theory for steadystate performance analysis and determination of maximum power-conversion capability of reluctance generators is presented. The high efficiency, high power factor, and high power density of the ALA-rotor reluctance generator are demonstrated through load tests on a laboratory model obtained from a 1.5 kW, 2-pole induction machine whose rotor was replaced by a single lamination/insulation-layer ALA rotor built for demonstration purposes. Unusually high values of Ld/LL ratio have been measured (Ld/Lq &gt; 16). The reluctance generator should be ideal as a DC-output brushless generator, with power electronics for voltage control.