Equivalent Magnetic Circuit Network Method Research Articles

Performance analysis of skewed PM linear synchronous motor according to various design parameters

This paper deals with the performance variation of permanent magnet linear synchronous motor (PMLSM) with skewed magnet according to various design parameters. The detent force, thrust and normal force characteristics are analyzed according to the variation of air-gap length, thickness of PM, overhang length of PM, width of PM and length of skew. And, the optimal length of skew that the detent force is minimized is determined. For the analysis, a 3-D equivalent magnetic circuit network (EMCN) method is used. To verify the analysis results, the results are compared with the measured ones.

3-D analysis of permanent magnet linear synchronous motor with magnet arrangement using equivalent magnetic circuit network method

In this paper, the fields and forces of permanent magnet linear synchronous motors (PMLSM) with segmented or skewed magnet arrangement are analyzed according to length of segment or skew. And, the effects according to the lateral overhang of magnet are investigated. For the analysis, 3-dimensional equivalent magnetic circuit network (3-D EMCN) method is used. The analysis results are compared with the experimental ones and show a reasonable agreement.

Lateral characteristic analysis of PMLSM considering overhang effect by 3 dimensional equivalent magnetic circuit network method

This paper represents the lateral characteristics of a permanent magnet linear synchronous motor (PMLSM) according to changes of overhang length. In order to analyze the overhang effect of a PMLSM with large airgap and finite width considering lateral displacement, a new 3-dimensional equivalent magnetic circuit network method (3-D EMCN) taking into account movement of the secondary in the lateral direction is introduced, which supplements the magnetic equivalent circuit by using a numerical technique. The 3-D EMCN can consider secondary movement without remeshing the elements because it uses the initial mesh continuously. The authors analyzed the characteristics for three overhang-type cases which must be problems in 3-D. The results are compared with experimental data and show reasonable agreement.

Dynamic analysis of radial force density in brushless DC motor using 3-D equivalent magnetic circuit network method

The distribution of radial force density in brushless permanent magnet DC motors is not uniform in the axial direction. The analysis of radial force density has to consider the 3-D shape of teeth and overhang, because the radial force density causes vibration and acts on the surface of teeth inconsistently. For the analysis, a new 3-D equivalent magnetic circuit network method is used to account for the rotor movement without remeshing. The radial force density is calculated and analyzed by Maxwell stress tensors and discrete Fourier transforms (DFT) respectively. The results of the 3-D equivalent magnetic circuit method have been compared with the results of 3-D FEM.

A method for reduction of cogging torque in brushless DC motor considering the distribution of magnetization by 3DEMCN

A method of reducing cogging torque and improving average torque has been studied by changing the dead zone angle of trapezoidal magnetization distribution of the ring type rotor magnet in a brushless DC motor (BLDCM). Because the BLDCM has a 3-D shape of its overhang, 3-D analysis should be used for exact computation of its magnetic field. A 3-D equivalent magnetic circuit network method (3-D EMCN) which can analyze an accurate 3-D magnetic field has been introduced. The analysis results of cogging torque using this 3-D EMCN are compared with those of the 3-D finite element method (3-D FEM) and experimental data.

Analysis of PMLSM using three dimensional equivalent magnetic circuit network method

This paper presents characteristics of a permanent magnet linear synchronous motor (PMLSM) considering lateral leakage flux and lateral displacement. In order to analyze the PMLSM with large air gap and finite width, a new three dimensional equivalent magnetic circuit network method (3D EMC) is introduced, which supplements the magnetic equivalent circuit by using numerical techniques. It can model flux ripple three-dimensionally by the teeth and slot structure of the PMLSM, and can take nonlinear magnetic phenomenon into account, which results from using the distributed magnetic circuit parameter, permeance. The analysis considering lateral flux and lateral displacement in the PMLSM which is problematic in 3D is performed using 3D EMC and is compared with the experimental value.