Do-Hyun Kang

Development of transverse flux linear motor with permanent-magnet excitation for direct drive applications

This paper presents the development of a transverse flux linear motor (TFLM) with permanent-magnet excitation for Stocker system, which is used for transferring glasses in the liquid crystal display industry. Magnetic field is analyzed by three-dimensional equivalent magnetic circuit network method and two-dimensional finite-element analysis is used to determine the influence of the end effect of a mover on the performance of TFLM. The experimental results of a prototyped motor are in good agreement with the analysis ones.

Optimum Design of Transverse Flux Linear Motor for Weight Reduction and Improvement Thrust Force Using Response Surface Methodology

Permanent magnet (PM)-type transverse flux linear motors (TFLMs) are electromagnetic devices which can develop directly powerful linear motion. The unique configuration makes power of output higher than longitudinal motors, but also it makes characteristic analysis difficulties. This paper deals with an effective analysis of PM-type TFLM by 3-D equivalent magnetic circuit network method (EMCNM). This paper presents optimum design of PM-type TFLM to reduce the weight of the machine with the constraints of thrust and detent force using response surface methodology (RSM). RSM was well adapted to make the analytical model of the minimum weight with constraints of thrust and detent forces and enable the objective function to be easily created and a great deal of the time in computation to be saved. Therefore, it is expected that the proposed optimization procedure using RSM can be easily utilized to solve the optimization problem of electric machines.

Static characteristics of linear BLDC motor using equivalent magnetic circuit and finite element method

This paper presents the static characteristics of the linear BLDC motor. An equivalent magnetic circuit model is derived for the prototype motor. The air-gap flux density is calculated using the equivalent magnetic circuit and compared with results from finite element analysis. The thrust force is measured for the prototype motor and is also compared with those from derived circuit model and FEA. These values agree well to show the validity of the equivalent circuit model. Using this equivalent circuit model, the thrust force density variation according to change of coil width to pole pitch can be expected at the design stage.

Tooth shape Optimization for Cogging Torque Reduction of Transverse Flux Rotary Motor using Design of Experiment and Response Surface Methodology

The aim of this paper is to present optimal design process and optimized model of transverse flux rotary motor. The stator and rotor tooth shapes are optimized to reduce cogging torque. Design of experiment and response surface methodology are used as an optimization method and all the experimental samples are obtained from three-dimensional finite-element analysis. The validity of this method is verified by comparing the optimized model to the initial model

Computation of inductance and static thrust of a permanent-magnet-type transverse flux linear motor

This paper proposes an effective method to calculate inductance and static thrust of a permanent magnet (PM)-type transverse flux linear motor (TFLM). The proposed method is a simple and fast way considering three-dimensional (3-D) flux path of the TFLM, and it can be used not only in characteristic assessment, but also in the design process. Two-dimensional (2-D) finite element analysis (FEA) and 3-D equivalent magnetic circuit network (EMCN) analysis are conducted to analyze the magnetic field. The usefulness of the proposed method is verified by comparison with measurement results.

Optimum Design of TFLM With Constraints for Weight Reduction Using Characteristic Function

This paper presents optimum design of transverse flux linear motor (TFLM) to reduce the weight of the machine with the constraints of thrust and detent force. Employing penalty functions, each constraint is included in the characteristic function, and the response value is determined by three dimensional magnetic field analyses. Finally, the contribution and effect of the each design variable on the characteristic function is evaluated by the analysis of means (ANOM), and optimum design set is determined. With this procedure, the weight of initially designed TFLM can be reduced 10% with small variation of thrust and detent force

Determination of Parameters Considering Magnetic Nonlinearity in Solid Core Transverse Flux Linear Motor for Dynamic Simulation

This paper presents methods to calculate motor parameters considering magnetic nonlinearity in solid core transverse flux linear motors (TFLM) for dynamic simulation. The magnetic field characteristics of the machine are analyzed by using 3-D equivalent magnetic circuit network (3-D EMCN) method, and parameters for dynamic simulation such as linkage flux, thrust, attraction force, and core loss are calculated by using the magnetic field analysis results. The calculated parameters are used as a form of lookup table in the dynamic simulation model. The accuracy of the method is examined by the comparison of input currents which are calculated by using the dynamic simulation model and measured for an example TFLM.

A design of transverse flux motor with permanent magnet shield

Transverse flux motors (TFMs) have a structure in which the direction of the current corresponds with the motion direction of the rotor, and a ring-shaped stator winding. The advantages of TFMs are high force density per volume and high efficiency because the resistance loss of winding end-turns is absent and the magnetic circuit is separated from the electric circuit. The authors designed two kinds of TFM, which are a variable reluctance type and a permanent magnet-shield type. The TFM with the PM-shield has a permanent magnet on the teeth of stator to shield it from airgap leakage flux, thereby increasing the power density. By analyzing these motors using 2-D and 3-D FEM and experimental measurements, the authors show the effect of the PM-shield.

Comparative Study of Stator Core Composition in Transverse Flux Rotary Machine

This paper deals with the comparison of magnetic characteristics in transverse flux rotary machine according to different stator core composition with the same rotor. Three different stator designs are considered in the analysis according to the material composition of inner and outer stator cores. Electromotive force (EMF), inductance, torque, and core losses are calculated by threedimensional finite element analysis. Calculated and measured results of back-EMF according to the analysis models in dependency on speed are presented.

Design and analysis of electromagnetic system in a magnetically levitated vehicle, KOMAG-01

An electromagnetically levitated vehicle, KOMAG-01, has been developed with eight axial-flux-type electromagnets for levitation and two single-sided linear induction motors (SLIMs) for propulsion. The magnet is designed using an analytical method and analyzed using the finite-element method (FEM) to find an optimum configuration. The SLIM is analyzed using a 2D FEM with current and magnetic vector potential to investigate end/edge effects in three different analyzing planes. After determining the design parameters, a SLIM was tested using a disc-type simulator. The operating characteristics of the machine are in reasonably good agreement with the analyzed data. >