• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.813-815
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• 2001

Permanent magnet DC motor is widely used in electrical tools, automotive manufacturing systems, electric vehicles, OA system drives, aircrafts and home appliances PM motors are suited for such an application, since they can be designed for high torque-to-speed ratio and efficiency. This paper deals with permanent magnet DC motor which is used in an electrical wheelchair. The motor has 6 PMs and 25 slots, and is coupled to the wheel with gears. In this study, motor design was carried out using finite element method. This paper discusses the design and construction of the prototype system and reports experimental results achieved from laboratory tests.

• Journal of Magnetics
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• v.17 no.2
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• pp.109-114
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• 2012

The torque characteristics of a surface-mounted permanent magnet synchronous motor (SPMSM) are analyzed in this study. The harmonics of the back electromotive force (EMF) and cogging torque are analyzed by the finite element method to study their effects on the torque ripple. Although low cogging torque can be achieved by varying geometric parameters such as the permanent magnet (PM) offset and notch depth on the stator teeth, the torque ripple is increased in some cases. The analysis results show that the ripple of the generated torque is determined by not only the amplitudes but also the phases of harmonics for the back EMF and cogging torque.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1797-1802
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• 2010

This paper proposes a new fuzzy speed controller based on the Takagi-Sugeno fuzzy method to achieve a robust speed control of a permanent magnet synchronous motor(PMSM). The proposed controller requires the information of the load torque, so the second-order load torque observer is used to estimate it. The LMI condition is derived for the existence of the proposed fuzzy speed controller, and the LMI parameterization to calculate the gain matrices of the controller is provided. It is proven that the augmented control system including the fuzzy speed controller and the load torque observer is exponentially stable. To evaluate the performance of the proposed fuzzy speed controller, the simulation and experimental results are presented under motor parameter and load torque variations. Finally, it is clearly verified that the proposed control method can be used to accurately control the speed of a permanent magnet synchronous motor.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.53-55
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• 2008

In high speed applications, the slotless permanent magnet(PM) motors appear an attractive solution, being almost insensitive to magneto-motive force harmonics and to pulse width modulation(PWM) current ripple and exhibiting lower stator iron losses and rotor losses (significant with square wave current control). So, this paper deals with methods for design of permanent magnet synchronous motor/generator.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.742-743
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• 2015

Magnetic couplings are do not require any mechanical contact with the power transmitted to the secondary side according to the primary side. For this reason, well-suited for isolated systems such as vacuums or high pressure. So, this paper presents the force characteristic analysis of the permanent magnet (PM) linear coupling with vertical magnetized using an analytical magnetic field calculations. Based on the definition of governing equations and magnetic vector potential, we obtained the analytical solutions according to the boundary condition for each of the regions. Also, we derived from the force generated in the permanent magnet surface using the Maxwell stress tensor. The analytical results are proved the validity by comparing to the finite element method (FEM).

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.1
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• pp.16-23
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• 2004

Permanent magnet-excited transverse flux linear motor(TFLM) is known to have more excellent ratio of force to weight than any other linear motors. But, thrust generated by phase current is non-linear with regard to current and relative position like switched reluctance motor. This makes current and speed controller design difficult. This paper presents a method on minimization of thrust ripple of permanent magnet-excited transverse flux linear motor. Using genetic algorithm(GA), optimal current waveform can be found under the constraint conditions such as current limit, minimum of ohmic loss and limited rate of change of current etc. The effectiveness is verified through computer simulation and experimental test results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.12
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• pp.789-796
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• 2000

This paper deals with magnetic field and characteristic analysis for ring type slotless synchronous motors by using analytical method. Since magnetic air-gap in the slotless motors is much larger than mechanical air-gap, it is necessary to analyze the magnetic flux distribution at the whole magnetic airgap region. therefore, this paper analyzes the duplicated magnetic field derived by both Permanent Magnet(PM) and armature current and estimates the back electromotive force and torque characteristic by subdividing the conductor region. The analysis results are verified by comparing with Finite Element Analysis(FEA) results.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.6-8
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• 2002

This paper presents the design and finite-element(FE) analysis of an axial-flux permanent-magnet synchronous generator using neodymium-iron-boron(NdFeB) magnets for directly coupled wind turbines. For the high energy density and light weight, an axial-flux permanent-magnet(PM) generator type is used. The simple magnetic equivalent circuit approach is used for initial design iteration, and the finite-element method is applied to analyze the detailed characteristics.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.40-42
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• 1999

High-speed brushless permanent magnet machines are good for compressor and aerospace applications, etc, since they are conductive to high efficiency, high power density, small size and low weight. This paper describes a diametrically magnetized PM motor with the rating of 4.3kW and 50000 rpm fur high-speed drive applications. To bear strong stress from high speed, rotor was designed cylindrical structure, was magnetized diametrically permanent magnet. The performance characteristic of motor was evaluated by means of FEA(Finite Element Analysis), no-load test And then, in order to find back-EMF constant, used FEA, search coil.

• Journal of Magnetics
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• v.6 no.3
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• pp.101-107
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• 2001

A model to describe the effect of stator slotting in the airgap region of a linear brushless permanent magnet motor (LBLPMM) is proposed for analytical prediction of magnetic field distribution. It is a two-dimensional model based on superposition of the effect of stator slotting and main field due to permanent magnet (PM) without stator slotting. The effect of stator slotting is expressed in form of a generalized equation, which is obtained by numerical analysis and is a function of motor geometric parameters, so the proposed model effectively accounts for the effect of stator slotting in the airgap field distribution according to change of motor geometry or relative motion of stator and armature. Results of prediction from the proposed model are compared with corresponding finite element analysis.