• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.749-751
• /
• 2004

This paper analyzed the characteristics of the claw pole PM step motor by using 3D FEM. In case of analysing this type of motor, 3 dimensional analysis is necessary for an accurate analysis due to the magnetizing component of the z-axis direction. As a main design variable, the magnetization, width and the effects of skewing was selected. The variation of the detent torque and the back EMF depending on the shape of the pole is also shown.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1061-1063
• /
• 2004

This paper deals with the application of cylindrical Halbach array to a PM motor capable of producing pure rotary motion, pure linear motion, or helical motion, The proposed motor consists of an exterior polar Halbach array for a rotary motion and interior cylindrical Halbach array for a linear one. The two- dimensional space harmonic method is employed for predicting the electromagnetic characteristics, with reference to the following parameters as variables: magnetic field, torque/thrust and back emf.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1070-1072
• /
• 2004

In this paper, the characteristic of slotless permanent magnet brushless motors analyze and compare parallel with radial way. This paper derive magnetic field solutions due to the PM. Torque, flux linkage and back emf are then derived. The results are shown in good conformity with those obtained from the commonly used finite element analysis.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.1085-1087
• /
• 2004

The space harmonic analysis, as an analytical method, is used to estimate the flux distribution in the air gap of the brushless motors in this paper. With the flux distribution, back-emf and torque characteristics can be estimated.[1-7] Therefore, the air gap flux distribution of surface type permanent magnet motor according to the motor specifications are studied to estimate the torque characteristics in this paper. To validate the analysis result of this method, 2-dimensional finite element analysis is performed and the air gap flux density is compared to that from space harmonic analysis.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.911-913
• /
• 2004

This paper presents characteristic analysis of claw-pole type generator. The analysis is performed using 2D equivalent model by 2D FEM. 3D FEM is used to check whether 2D equivalent model reflects the magnetic characteristics of the actual machine. Initially, 2D equivalent model of the claw-pole type generator is designed only by 3D geometry. Using 2D equivalent model, back emf characteristics are estimated and compared to measurements. The analysis results agree with measurements well and take less time comparing to 3D FEM.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.12
• /
• pp.576-585
• /
• 2005

This paper deals with the electromagnetic field analysis of slotless brushless permanent magnet machines with three different magnetization patterns such as Halbach, parallel and radial magnetization. The magnetization modeling of Halbach, parallel and radial magnetization is performed analytically. And then, analytical solutions for open-circuit field distributions, armature reaction field distributions, flux linkages due to PMs and stator windings, torque, back-emf and inductance are derived in terms of magnetic vector potential and two-dimensional (2-d) polar coordinate systems. The analytical results are validated extensively by finite element (FE) analyses. The magnet volume required in order to produce identical flux density is compared with each magnetization. Finally, analytical solutions and derivation procedures of those presented in this paper can be applied to slotless and slotted brushless permanent magnet AC and DC machines.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.9
• /
• pp.490-497
• /
• 1999

This paper presents a novel current control method to reduce the current ripple due to commutation in brushless DC motor fed with unipolar PWM voltage source inverter. The proposed current control method can reduce the current ripple due to commutation in high speed range where the DC link voltage of the inverter is less than four times of the phase back-emf. The effectiveness of the proposed current control method is verified with digital simulations and experiments on the 250W brushless DC motor drive systems.

• Journal of Power Electronics
• /
• v.14 no.3
• /
• pp.541-548
• /
• 2014

This paper presents a simple lead angle adjustment method for brushless DC motors. The proposed method is based on the motor current dynamics analysis during the current commutation interval. With the proposed scheme, the phase current and phase back-EMF voltage are in phase and the BLDC motor and drive system have a high efficiency induced by the reduced copper and conduction losses. Experimental results are shown to validate the proposed method.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1048-1050
• /
• 2003

Recently, many linear motion generators and motors are rapidly finding applications that ranges from short stroke linear motion vibrators, such as dynamic con type loud speakers to stilting engine driven linear reciprocating alternators, compressors, textile machines etc. In this paper, we analyze the characteristics of tubular linear motor with Halbach and radial magnet array respectively. We already derived magnetic field solutions due to the PMs and to the currents and Motor thrust. On the basis of analytical field solutions, this paper deals with flux linkages and back emf. The results are validated extensively by comparison with finite element analyses. Then, this parer also presents thrust characteristics according to design parameters for each model.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1057-1059
• /
• 2003

This paper presents drive analysis of slotless air-cored PM linear synchronous motor using two-dimensional analytical method. In order to calculate dynamic characteristic, back-EMF and linkage flux are calculated by Permanent Magnet Field and also inductance are given by slotless winding current coil. PMLSM drive simulation is performed by PI control system.