• Proceedings of the Korean Magnestics Society Conference
• /
• 2015.11a
• /
• pp.178-178
• /
• 2015

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.761-763
• /
• 2004

Due to the high peripheral speed of the rotor and the relatively high conductivity of the magnets used, rotor eddy current loss can be substantial. On the basis of the coupled FEM and analytical method, this paper deals with the rotor loss analysis in permanent magnet high-speed machine with 3-phase rectifier.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1001-1003
• /
• 2004

In this paper, the vibration control of CPM(Controlled-Permanent Magnet) type magnetic levitation system of 1ton is designed and implemented. The target to be controlled has 8 magnets and 4 corners of the maglev module are levitated using a digital feedback controller. The designed controller includes PID type gap controller and speed observer. Its performance is validated by some kinds of experiments.

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.83-85
• /
• 1995

In a permanent magnet motor, cogging torque arises from the intersection of the rotor magnets with the steel teeth on the stator. This paper describes design measures which can be taken to reduce the cogging torque. In this paper for the optimal shape design of brushless DC motor, evolution strategy is investigated to find the dimension of stator of BLDC motor that minimizes the cogging torque. The corresponding field analysis is performed by two-dimensional finite element method.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1553-1555
• /
• 2005

This paper presents a design of lossless hybrid-type magnetically-levitated vehicle. The lossless hybrid-type system is implemented by a permanent magnet and electromagnet. The target plant consists of eight hybrid-type magnets and in the steady-state, no current is needed to support the load. The design procedure is described and the results of this work are shown.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.6 s.171
• /
• pp.70-75
• /
• 2005

Many researches have been focused on optimal designs of a pole shape in order to reduce cogging torques, which are generated between permanent magnets and slots. In this paper, an adaptive controller is proposed fur reducing the effect of cogging torques in servo motors. The controller stabilizes the control system and shows an excellent trajectory tracking performance compared to the conventional PD controller.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2008.12a
• /
• pp.224.1-224.1
• /
• 2008

• Proceedings of the Korean Magnestics Society Conference
• /
• 2016.11a
• /
• pp.47-47
• /
• 2016

• Tribology and Lubricants
• /
• v.23 no.6
• /
• pp.283-287
• /
• 2007

Permanent-magnet (PM) passive bearings use the repulsive forces between the rotor and the stator magnets for the bearing function. It is desirable that the stiffness of the bearing is maximized with the given volume of the magnet. The stiffness is affected by the magnet strength, the number of layers, and the magnetization patterns. Previously, finite-element method (FEM) has been used to maximize the stiffness of the bearing. In this paper, we used the equivalent current sheet method to calculate the stiffness. The validity of this approach is checked against FEM results. The optimized bearing is applied to a micro flywheel energy storage system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.11
• /
• pp.1541-1543
• /
• 2013

This paper presents a spherical motor which can control in multi-degree of freedom operation. The spherical motor has been researched by many types of structure. Thhis paper shows a spherical shaped airgap and surfaced permanent magnets. Especially, The motor consists of dual rotor cores. Unlike a cylindrical motor, the spherical motor design can be considered with azimuth direction on spherical coordinates. Therefore the permanent magnet surfaced on the rotor need to be designed optimally in order to generate a sinusoidal magnetic flux density in the airgap. This paper presents results of optimal design for reducing torque ripple of the multi-degree of freedom spherical motor.