• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.564-569
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• 2012

This paper proposes a hybrid-excited linear synchronous motor (LSM) that has potential applications in a magnetically levitated vehicle. The levitation and thrust force characteristics of the LSM are investigated by means of three-dimensional (3-D) numerical electromagnetic FEM calculations and experimental verification. Compared to a conventional LSM with electromagnets, a hybrid-excited LSM can improve levitation force/weight ratios, and reduce the power consumption of the vehicle. Because the two-dimensional (2-D) FE analysis model describes only the center section of the physical device, it cannot express the complex behavior of leakage flux, which this study is able to predicts along with levitation and thrust force characteristics by 3-D FEM calculations. A static force tester for a hybrid-excited LSM has been manufactured and tested in order to verify these predictions. The experimental results confirm the validity of the 3-D FEM calculation scheme for the description of a hybrid-excited LSM.

• Journal of Magnetics
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• v.14 no.1
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• pp.47-51
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• 2009

The coreless linear synchronous motor (coreless LSM) has been widely used as a driving source of semiconductor production processes for machine speeding up, positioning accuracy and simple maintenance. However, this coreless LSM suffers the disadvantage of decreased thrust force created by the leakage of magnetic flux. With the goal of increasing the generated thrust force and decreasing the cogging force, the slot of the core part was removed and a moving-coil-type slotless LSM (moving-coil-type slotless LSM) is proposed in this paper. Although this moving-coil-type slotless LSM with a back-yoke at the primary side demonstrated an increase in the generated thrust force, it remained capable of generating the cogging force when the primary side was moved due to the position between the permanent magnet and the back-yoke. Therefore, we attempted to decrease the cogging force of the moving-coil-type slotless LSM. We found that the back-yoke length at the primary side needs to be made $0.5{\tau}$ longer than the integral multiple of the magnetic pole pitch in order to decrease the cogging force created by the moving-coil-type slotless LSM.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.196-202
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• 2017

A very long test track is required for high-speed operation test of the real-scale Linear Synchronous Motor (LSM) for ultra-high-speed trains. The required length results in huge construction cost and economic loss if any error occurs during development. Therefore, validation study of the LSM design technology using a low-cost small-scale model must be carried out in the early research stages. It is possible to deduce an optimal winding method for the armature and determine the mechanical properties of the LSM through a performance tester that applies a rotary-type small-scale LSM model. In addition, it is possible to utilize previous research on LSM control systems. Therefore, a basic design model, comprising a rotary-type LSM tester that meets the requirements for the propulsion of 600km/h-class ultra-high-speed trains, is derived in this study. Finally, an optimal model, which has a stable structure under the condition of 1500rpm or more high-speed rotation, is derived by electromagnetic and mechanical stiffness analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.75-84
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• 2014

A linear synchronous motor (Linear Synchronous Motor, under LSM) is suitable for Maglev train. This is 500km/h or more for running high-speed propulsion system of high-efficiency, high-output characteristics. Also, as high-speed running, it is needed solution to reduce output ripple component cause bad riding like noise and vibration. So this paper was designed 500km/h-class Maglev train and analyzed characteristics of the LSM base model using finite element analysis method. Further, improved model is designed to improve characteristics of thrust and levitation force by enforcing design parameters analysis and sensitivity analysis. And it was applied skew on field in order to reduce the ripple component still remaining. Skew interpretation of the two-dimensional is proposed and this is verified by carrying out three-dimensional finite element analysis comparing two values. It proved to be valid of skew of the two-dimensional analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1602-1607
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• 2014

This paper deals with the design and property analysis of 7kW-class small-scaled superconducting Linear Synchronous Motor (LSM) and testing equipment for a number of performance pre-tests prior to the development of coreless-type superconducting LSM suitable for 600km/h very high speed train. First, the basic design and property analysis are conducted before developing a small-scaled superconducting LSM model with 2-pole superconducting electromagnets, and additionally the cost-down design of the superconducting electromagnets is conducted to use less high-Tc superconducting wire. Finally, the superconducting magnet coil span is selected at 120mm, and input ground armature current of 670Aturns is required to produce 44.7N of thrust based on research findings.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.450-457
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• 1998

Abstract - Linear Synchronous Motor has a large airgap comparing with rotary-type motor and especially, Permanent Magnet Linear Synchronous Motor(PM-LSM) which uses permanent magnet as a magnetic field, has a very large effective magnet airgap owing to permanent magnet structure. Accordingly, in case of 2-D analysis of the motor, the analysis error becomes large because leakage flux by which normal direction of the analysis region can not be considered, In this paper, the characteristic of PM-LSM for Maglev vehicle is analyzed exactly by 3-D Finite Element Method(3-D FEM). As the result, the effect of lateral-direction airgap magnetic flux density distribution on the analysis precision has been investigated and the motor characteristics according to primary motor parameter have been also made clear quantitatively. The accuracy of 3-D FEM has been confirmed by comparing the calculated results with the experimental results.

• International Journal of Railway
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• v.3 no.1
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• pp.14-18
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• 2010

This paper describes design and characteristic analysis of long primary type linear synchronous motor (LSM) for high speed train system. LSM is designed using loading distribution method and magnetic equivalent circuit. For characteristic analysis of LSM, analytical and numerical methods are applied. Analytical method for solving the magnetic field distribution of the analytic model is based on the Maxwell’s equations. Using the characteristic equation and magnetic equivalent circuit, we analyze the effect of variation of parameters, and then we validate the result by comparing with numerical method by finite element method (FEM). We compare the analytical method with numerical method for analyzing the effect by variable parameters. This result will be useful of design and forecast of performance without FEM.

• Journal of Power Electronics
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• v.16 no.2
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• pp.598-609
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• 2016

The good control performance of permanent magnet linear synchronous motor (LSM) drive systems is difficult to achieve using linear controllers because of uncertainty effects, such as fictitious forces. A backstepping control system using adaptive modified recurrent Laguerre orthogonal polynomial neural network uncertainty observer (OPNNUO) is proposed to increase the robustness of LSM drive systems. First, a field-oriented mechanism is applied to formulate a dynamic equation for an LSM drive system. Second, a backstepping approach is proposed to control the motion of the LSM drive system. With the proposed backstepping control system, the mover position of the LSM drive achieves good transient control performance and robustness. As the LSM drive system is prone to nonlinear and time-varying uncertainties, an adaptive modified recurrent Laguerre OPNNUO is proposed to estimate lumped uncertainties and thereby enhance the robustness of the LSM drive system. The on-line parameter training methodology of the modified recurrent Laguerre OPNN is based on the Lyapunov stability theorem. Furthermore, two optimal learning rates of the modified recurrent Laguerre OPNN are derived to accelerate parameter convergence. Finally, the effectiveness of the proposed control system is verified by experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1820-1826
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• 2016

This paper deals with dynamic characteristics of the experimental magnetic levitation vehicle employing LSM(Linear Synchronous Motor) for propulsion. To predict the dynamic characteristics of the system, the dynamic model which is composed of the electrical elements such as electromagnets and LSM and mechanical components and is developed based on multibody dynamics is developed. The resulting system equations of motion for the model are a coupled one representing all the mechanical and electrical parts. To verify the dynamic model of the system, air gaps are measured in both running tests and simulation, and the frequency characteristics of air gaps are analyzed. From the results, it can be seen that the frequency responses are almost the same. Finally, to evaluate the levitation stability and the designed controller, numerical simulations are carried out.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.905-911
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• 2009

The viscosity drive method by the wheel which is widely used in the conventional railway systems needs a large friction force between the wheel and the guide-rail, which brings on a thrust force for a quick acceleration and a high-speed travelling. In addition, the viscosity drive method needs an increase of the vehicle weight for a large friction force. However, a maglev train is possible to be driven by the electro-magnet instead of the wheel, which produces a levitation and thrust force without any contact. In general, low-speed maglev train uses a linear induction motor(LIM) for propulsion that is operated under 300[km/h] due to the power-collecting and end-effect problems of LIM. In case of high-speed maglev train, a linear synchronous motor(LSM) is more suitable than LIM because of a high-efficiency and high-output properties. LSM has a driving principle as same as a conventional rotary synchronous motor(RSM), and the torque of RSM becomes the thrust force of LSM. A conventional LSM has relatively large air-gap compared with a conventional RSM. So, it must be achieved a design that is considered normal force by finite-asymmetric structure, end-effect on the entry and exit part, and support structure of a moving part. Therefore, in this research, authors accomplish a conceptualizing and basic design of a small-scaled LSM, and characteristics analysis using FEM.