• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.9
• /
• pp.1571-1576
• /
• 2007

This report describes the analytical characteristic of sinewave air gap flux density for the brushless AC motor with surface permanent magnet. The analysis of sinewave air gap flux density is the key to expect the performance of back EMF for the design of brushless AC motor. The numerical analysis and FEM analysis are performed to adopt radial and parallel flux magnetization of magnet on the rotor. And it is also executed to vary the magnet arc angle and arc radius for the condition of constant and non constant air gap. This report is focused on the characteristic of sinewave air gap flux density for permanent magnet of surface brushless AC motor. This results also have more reliable data against the previous paper which had the representative numerical analysis of air gap flux density[1][2].

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.12
• /
• pp.1255-1260
• /
• 2004

A moving-magnet type pickup actuator has an assembly error. That is, the actuating Part of an actuator is shifted from initial position after we assemble it into yoke. This Is the result of an effect of magnetic force between magnet and yoke. We performed magnetic-analysis using FEA. As a result of simulation, we improved the assembling efficiency for moving-magnet type actuator.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.6
• /
• pp.1954-1959
• /
• 2014

This paper attempts to design and present a comparison of classical Direct Torque Flux Control (DTFC) for Line-Start Permanent Magnet Synchronous Motor (LSPMSM) and its equal Permanent Magnet Synchronous Motor (PMSM). In order to present an in-depth analysis, both motors for DTFC Voltage Source Inverter (VSI)-fed in the same situations of different conditions are simulated and tested. The advantages of the proposed method for LSPMSM over the PMSM are discussed and analyzed.

• Journal of Magnetics
• /
• v.15 no.3
• /
• pp.128-131
• /
• 2010

In this paper, we propose a new design of the permanent magnet reluctance wheel which will make it possible to attach the robot to a vertical plane and move it. In the newly suggested design, a permanent magnet is utilized to enhance the adhesive force during attachment, and an electromagnet is produced to weaken the magnetic field of the permanent magnet and reduce the adhesive force for easier detachment of wheels from steel plates. To characterize the performance of this new wheel design, a 3-D finite element analysis is executed using a commercial FE program. The results show that the adhesive force is reduced effectively by the electromagnet which flows in the reverse direction of the magnetic loop of the permanent magnet when the current is supplied to the coil.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.37 no.8
• /
• pp.521-527
• /
• 1988

At present superconducting magnets have been feasible for many applications which require high field or highly homogeneous field that it is too difficult to be produced by conventional electromagnets. This paper is a stuny on Donble Helmholtz superconducting magnet and newly configurated superconducting magnet that realize highly homogeneous field with the minimum magnet volume. Nonlinear programming method is effectively used for the minimum volume of superconducting magnet that realizes the desired field intensity and high homogeneity. The results on Double Helmholtz and newly configurated superducting magnets that are presented in this paper are largely improved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.356-361
• /
• 2004

A moving-magnet type pickup actuator has an assembly error . That is, the actuating part of an actuator is shifted from initial position after we assemble it into yoke. This is the result of an effect of magnetic force between magnet and yoke. We performed magnetic-analysis using FEA. As a result of simulation, we improved the assembl ing efficiency for moving-magnet type actuator.

• Proceedings of the KIPE Conference
• /
• 2003.07b
• /
• pp.824-827
• /
• 2003

Recently, Development of Rare Earth Permanent magnet with the high remanence, high coercivity allow the design of brushless motors with very high efficiency over a wide speed range. Cogging torque is produced in a permanent magnet by magnetic attraction between the rotor mounted permanent magnet and the stator teeth. It is an undesired effect that contributes to the machines output ripple, vibration, and noise. This cogging torque can be reduced by variation of magnet arc length, airgap length, magnet thickness, shifting the magnetic pole and varying the radial shoe depth and etc. In this paper, Some airgap length and magnet arc that reduce cogging torque are found by FEM(Finite element method). The SPM type of high-capacity BLDC motor is optimized as a sample model.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.528-538
• /
• 1996

A magent console is critical element since its homogeneity is essential to the performance of a nuclear magnetic resonance (NMR) based sensor. Geometry and properties of magnet materials determine the magnetic flux density and homogeneity of the console. This study is carried out to develop a design scheme of the magnet console using ANSYS to reduce the design error of the magnet console compared . To enhance the performance of the magnet console, corner steel was proposed and validated by simulation and manufactured one. The corner steel increased the magnetic flux density (B) by about 1% and enhanced homogeneity by approximately 3 times. There was about 3% difference between simulated and measured B values.

• Journal of Magnetics
• /
• v.18 no.2
• /
• pp.95-104
• /
• 2013

This paper presents a general analytical method for predicting the magnetic fields of different Halbach magnet arrays with or without back iron mounted on slotless permanent magnet (PM) linear machines. By using Fourier decomposition, the magnetization components of four typical Halbach magnet arrays are determined. By applying special synthetic boundary conditions on the PM surfaces, the expressions of their magnetic field distributions are derived based on the magnetic scalar potential (MSP), which are simpler than those based on the magnetic vector potential (MVP). The correctness of the method is validated by finite element analysis. The harmonics of airgap flux density waveforms of these Halbach magnet arrays with or without back iron are also compared and optimized.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.163-166
• /
• 2001

It leaves much room for improvement that UTM-01 is of practical use. Therefor we will design of longitudinal pole magnet for UTM-02 system. The design of new magnet is based on light weight for bogie system. The new magnet for UTM-02 was reduced weight of magnet is 18kg per one, then it was ratio lift to weight is 10.13.