• Journal of the Semiconductor & Display Technology
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• v.4 no.1 s.10
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• pp.1-8
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• 2005

Linear motor can be directly applied to the system needed linear motions without rotary motions. To control high-speed and high-resolution, the development of the linear motors is recently required in the high-integrated and speed process industry This paper presents thermal and vibration analyses as well as measurement standards of the newly developed linear motors through analyzing the thermal behaviors and vibration characteristics of the advanced products. The thermal measurements are conducted for comparing the developed linear motor with the advanced linear motor and the Finite Volume Method(FVM) is used to identify the measurement results. And then the vibration measurement are carried out in the developed and advanced linear motors with respect to the speed. To identify the measurement results, the Finite Element Method is utilized in the developed and advanced linear motors, respectively. The FVM, FEM, and experiments make it possible to understand these characteristics. The improvement is suggested through their results conducted experiment and analyses.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.316-320
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic oscillator which generates elliptical oscillations. Elliptical oscillations are generated by synthesizing two degenerated modes. The design of a stator for an Ultrasonic linear motor was optimized with respect to vibration mode and direction of vibratory displacement by employing the finite element method. The motors were designed by varying the width of stator vibrator and the thickness, the length and the position of piezoceramics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.411-414
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• 2000

An ultrasonic linear motor was composed of a slider and a stator vibrator including piezoelectric material and elastic material. The ultrasonic linear motors mainly consist of an ultrasonic oscillator which generates elliptical oscillations. Elliptical oscillations are generated by synthesizing two degenerated modes. Direction of vibratory displacement was analyzed by employing the finite element method. So, we could recognize that the direction of the slider's movement was controlled by changing the Phase difference of the drive voltage.

• Journal of Power Electronics
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• v.11 no.1
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• pp.105-111
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• 2011

By having accurate knowledge of the magnetic field distribution and the thrust calculation in linear synchronous motors, assessing the performance and optimization of the motor design are possible. In this paper, after carrying out a performance analysis of a single-sided wound secondary linear synchronous motor by varying the motor design parameters in a layer model and a d-q model, machine single- and multi-objective design optimizations are carried out to improve the thrust density of the motor based on the motor weight and the motor efficiency multiplied by its power factor by defining various objective functions including a flexible objective function. A genetic algorithm is employed to search for the optimal design. The results confirm that an overall improvement in the thrust mean, efficiency multiplied by the power factor, and thrust to the motor weight ratio are obtained. Several design conclusions are drawn from the motor analysis and the design optimization. Finally, a finite element analysis is employed to evaluate the effectiveness of the employed machine models and the proposed optimization method.

• International Journal of Railway
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• v.9 no.2
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• pp.41-45
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• 2016

In this paper, a study on the efficiency improvement of the magnetic levitation train using the LIM (Linear Induction Motor) was presented. The maglev train has the advantage of being environmentally friendly since much less noise and dust is produced. However, due to structural limitation, compared to a rotating induction motor, linear induction motor, the main propulsion engine of the maglev train has a relatively greater air gap and hence has the lower operation efficiency. In this paper, the relationship between the operating condition of the train and the slip frequency has been investigated to find out the optimum slip frequency that might improve the efficiency of the magnetic levitation train with linear induction motor. The slip frequency is variable during the operation by this relationship only within a range that does not affect the levitation system of the train. After that, the comparison of the efficiency between the conventional control method with the slip frequency fixed at 13.5[Hz] and the proposed method with the slip frequency variable from 9.5[Hz] to 6.5[Hz] has been conducted by simulation using Simplorer. Experiments of 19.5[ton] magnetic levitation trains owned by Korea Institute of Machinery and Materials were carried out to verify the simulation results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.154-161
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• 2005

In the machine tool industry, direct drive linear motor technology is an interesting means to achieve high acceleration, and to increase reliability. This paper analyzes and compares the characteristics of a tubular linear motor with Halbach and radial magnet array, respectively. First, the governing equations are established analytically in terms of the magnetic vector potential and two dimensional cylindrical coordinate systems. Then, we derive magnetic field solutions due to the PMs and the currents. Motor thrust, flux linkage and back emf are also derived. The results are shown to be in good conformity with those obtained from the commonly used finite element method. Finally, control parameters are obtained from analytical solutions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.594-599
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• 2007

A dosed-loop sensorless stroke control system for a linear compressor has been designed. The motor parameters are identified as a function of the piston position and the motor current. They are stored in ROM table and used later for the accurate estimation of piston position. Also it was attempted to approximate the identified motor parameters to the 2nd-order surface functions. The 2nd-order surface functions are divided into 2 or 4 sub-sections for more precise identification of motor parameters. Some experimental results are given in order to show the feasibility of the proposed control schemes for linear compressors.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.7
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• pp.1231-1235
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• 2007

This paper presents the dynamic characteristics of a linear brushless dc (BLDC) motor with permanent magnet excitation for the precision conveyor according to the load condition. Dynamic performance of the linear BLDC motor driven with 6 step inverter such as thrust force and speed is simulated by finite element method coupling with external circuit and measured for the prototype motor. The results of finite element analysis are compared to the experimental results and verify reliability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.64-68
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• 1997

In this paper, a controller for the linear motor with high speed and stiffness is implemented using SERCOS interface which is a real time communication protocol between the numerical controller(NC) and the motor driver. The proposed controller is mainly composed of current, speed, and position controller, which are designed using the 32-bit DSP(TMS320C31), a high-integrated logic device (EPM7128), and Intelligent Power Module(IPM) to enhance reliability and compactness of the system. The experimental results show the effective performance of the proposed controller for he linear motor with high speed and stiffness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.404-407
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• 2004

Linear ultrasonic motor by bimorph. Transducer for linear ultrasonic motor with symmetric and anti-symmetric modes was studied. The transducer was composed of two piezoelectric ceramic that cross at right angles with each other at tip. In order to exist length vibration mode two piezoelectric ceramics must have 90-degree phase difference with each other. As a result, tip of transducer moves in elliptical motion. Elliptical trajectory of transducer was analyzed by employing the (mite element method(FEM). From the result, the linear ultrasonic motor was measured for characteristics. In this paper, vibration shape of transducer was simulated and the resonant frequency, stabilization frequency and maximum displacement were calculated using the FEA.