• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.4
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• pp.145-151
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• 1999

This paper presents the characteristic analysis method of PMLSM based on the Space Harmonic Analysis method considering the effect of stator slots. The magnetic field for unslotted primary can be easily calculated by the conventional space harmonic analysis method and the resultant magnetic field including slot effect is obtained using the concept of the virtual Equivalent Magnetizing Current(EMC) on primary core. And the influence of space harmonics in airgap flux density and static thrust due to slots is evaluated. In this paper, the results of the analytical method are compared with not only the experimental ones but ones of FEM to verify the validity of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.8
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• pp.463-468
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• 2004

This paper was applied space harmonic method as a characteristic analysis technique for slotless PMLSM. There is advantages of active response to the change of design parameters as well as reduction of the calculation time. The method can be overcome disadvantages of finite element analysis that needs long times calculation, repetitions of pre and post-process. In this paper, 3D-space harmonic method was applied to consider the precise description of end turn coil shape and the changes of characteristic according to changes of length of z-axis direction. The thrust of optimal design was performed using genetic algorithm to enhance the thrust which is the disadvantage of slotless type PMLSM. For design parameters, width of permanent magnet, width of coil, width of coil inner and lengths of z-axis direction were selected. For objective functions. thrust per weight. thrust per volume. multi-objective function was selected.

• Journal of Electrical Engineering and Technology
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• v.7 no.5
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• pp.730-735
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• 2012

This paper presents a method to design the waveform of a back electromotive force (back EMF) of an axial flux permanent magnet (AFPM) motor using printed circuit board (PCB) windings. When the magnetization distribution of permanent magnet (PM) is given, the magnetic field in the air gap region is calculated by the quasi three dimensional (3D) space harmonic analysis (SHA) method. Once the flux density distribution in the winding region is determined, the required shape of the back EMF can be obtained by adjusting the winding distribution. This can be done by modifying the distance between patterns of PCB to control the harmonics in the winding distribution. The proposed method is verified by finite element analysis (FEA) results and it shows the usefulness of the method in eliminating a specific harmonic component in the back EMF waveform of a motor.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.6
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• pp.255-262
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• 2001

This paper deals with characteristic analysis method of the slotless type Permanent Magnet Linear Synchronous Motor(PMLSM) using the space harmonic method. Analysis models of the PM and the armature current are described by the magnetization configurations taking into account the 2D and 3D distribution. In 3D analysis, the thrust and normal force can be calculated more accurately, because it can consider the z component flux density which is impossible in 2D analysis. In order to verify the validity of the proposed method, the results of the analytic method are compared with not only the experimental ones but ones of Finite Element Method(FEM).

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.162-167
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• 2002

This paper presents the dynamic analysis method for a slotless permanent magnet linear synchronous motor (PMLSM) using the 3-D space harmonic method. Instantaneous emf and thrust are considered by movement of the PM and instantaneous armature current instead of $K_E$ (back-emf constant) and $K_F$(thrust force constant) for accurate results. The results of magnetic field distribution, back-emf, inductance, and thrust are in agreement with 2-D FEM and experimental results. To confirm the validity of this method, the calculated results are compared to measured ones.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.379-386
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• 2002

This paper deals with dynamic analysis method of a slotless type permanent magnet linear synchronous motor(PMLSM) using 3-dimensional space harmonic method. The results are good agreement with FEA results because that slotless type PMLSM has simple structure and no saturation of core. And then, Under open-loop control, starting characteristic is analyzed by voltage equation combining with dynamic equation. In order to obtain more accuracy results, this paper use instantaneous back-EMF and thrust instead of back-EMF constant and thrust constant.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.7
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• pp.352-360
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• 2003

This paper deals with a simple method in order to analyze and compare the harmonic characteristics in the multi-level inverter. Generally, the magnitude of harmonic components becomes different according to the multi-carrier Pulse Width Modulation(PWM) techniques, the modulation index($M_i$) and the switching frequency The previous papers analyzed the harmonic characteristics from the viewpoint of the space voltage vector. Hence, the calculation of the harmonic vector becomes more difficult and complex in 4-level or over 5-level. However, the proposed method has reduced an amount of calculation and simplified the process of it, using the relationship between the reference voltage and the output phase voltage to the load neutral point. It is applied to the 5-level cascade inverter and the harmonic characteristics for each multi-carrier PWM technique are compared through the simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1153-1161
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• 2010

An efficient solution method for harmonic balance techniques with Fourier transform is presented for periodic unsteady flow problems. The present partially-implicit harmonic balance treats the flux terms implicitly and the harmonic source term is solved explicitly. The convergence of the partially Implicit method is much faster than the explicit Runge-Kutta harmonic balance method. The method does not need to compute the additional flux Jacobian matrix from the implicit harmonic source term. Compared with fully implicit harmonic balance method, this partial approach turns out to have good convergence property. Oscillating flows over NACA0012 airfoil are considered to verify the method and to compare with results of explicit R-K(Runge-Kutta) and dual time stepping methods.

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

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1639-1647
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• 2016

This paper deals with eddy current loss analysis of Slotless Double sided Cored type permanent magnet linear generator by using analytical method, space harmonic method. In order to calculate eddy current, this paper derives analytical solution by the Maxwell equation, magnetic vector potential, Faraday's law and a two-dimensional(2-D) cartesian coordinate system. First, we derived the armature reaction field distribution produced by armature wingding current. Second, by using derived armature reaction field solution, the analytical solution for eddy current density distribution are also obtained. Finally, the analytical solution for eddy current loss induced in permanent magnets(PMs) are derived by using equivalent, electrical resistance calculated from PMs volume and eddy current density distribution solution. The analytical result from space harmonic method are validated extensively by comparing with finite element method(FEM).