• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.466-469
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• 1995

This paper presents a design and performance of the 6 D.O.F linear motion table with a magnetic bearing suspension. The linear positioning of the table with a 150mm stroke is driven by a brushless DC Linear motor and the other attitudes of the stage are controlled by the analog PD controller with magnetic bearing actuators. Each magnetic bearing unit which consists of 3 electromagnets, 3 capacitance probes and 3 backup bearings affords controlled forces by detecting the air gap between the probes and guideways. An integral type capacitance probe amplifier is equipped on the upper plate of the table so that the probe line to the probe amplifier can be shorter therefore the problems due to the stray capacitance and noise can be reduced. Form the pitch-yaw errormeasured by the autocollimator, the vertical and horizont straightness errors of the table are derived that they are maintained below 1.mu. m over 100mm stroke. The positioning accuracy of the linear motion is maintained below 2 .mu. m and the repeatability error is below 1 .mu. m

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1995년도 추계학술발표회논문집
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• pp.101-104
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• 1995

The linear control of DC Link voltage in PWM inverter is very importent to estimate the goodness of PWM method. In motor control system, for the maximum torque on full region operating, the whole of DC Link voltage region must be used. 3 phase sinusoidal PWM inverter has a low efficienty at the using of output voltage. according to make better the efficiency, new improved PWM control method is proposed. The results of experimentation and simulation are included to verify the validity of this method.

• 대한기계학회논문집A
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• 제31권12호
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• pp.1173-1179
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• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1017-1018
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• 2011

This paper deals with a magnetic field analysis on brushless DC(BLDC) motor with radial magnetization permanent magnet. In order to analyze the magnetic field, multi-layer analysis based on space harmonics method is employed. Finally, the analytical results are validated by non-linear Finite Element Analysis(FEA).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.6-9
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• 1997

The study is analyzed the thrust fon:e of moving type Linear DC Motor(MM-LDM). The MM-LDM consists of a stator (platen) and mover (forcer). One of the method for calculating tile thrust of an MM-LDM is to analyze the energy gradient which is determined by the distribution of magnet flux. However, this method is very difficult when used to calculate the thrust force of this kind of LDM. The stored energy in the MM-LDM can be obtained by measuring the self-inductance and mutual-inductance of equivalent circuit of the MM-LOM and this energy gradient gives the thrust. The calculation of thrust force included in this motor shows that the mutual inductance has large influence on the generation of thrust force.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.22-24
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• 1997

The 4-pole LHSM was composed of the figure-of-eight shaped 3-phase armature windings. DC field windings, and the segmented secondary with the transverse bar track. The motor was designed on the base of the performance characteristic equations and the equivalent circuit model, with the coefficients of the magnetic shape. These coefficients were computed from the analytical expressions and examined from FEM analysis. The magnetic equivalent circuit of 3-D model of LHSM was obtained. and this concept provided the equivalent models for 2-D FEM analysis. Therefore, the airgap field, the lift and thrust force were calculated and compared with the results of magnetic equivalent circuit method.

• Journal of Power Electronics
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• 제3권1호
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• pp.10-16
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• 2003

Implementation and experimental verification of a simple neuro-controller (SNC) as a speed controller for a brush less DC (BLDC) motor is presented. The SNC with one weight and a linear hard limit activation function is trained on-line using the back propagation algorithm. A modified error function is used to ensure good performance during the on-line training, which has been used without previous off-line training. The SNC has been implemented using a computer-interface card mounted on a PC. The driving system performance has been investigated by a number of experimental tests for a variety of input reference speed trajectories.

• 대한전기학회논문지
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• 제43권7호
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• pp.1186-1192
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• 1994

This paper presents an algorithm to design a robust digital model following servo control system in which optimal linear quadratic regulator problem is used to design the control system that make the step/ramp response of the plant kept close to a specified ideal step/ramp response of the model. The quadratic criterion function for a continuous system is used to design the robust digital servo control system. The feasibility of the design technique is shown by the simulation and the proposed method is applied to the speed control of DC servo motor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.25-29
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• 2001

The BLDCM (Brushless DC Motor) characterized by linear torque to current, and speed to voltage has low acoustic noise, and fast dynamic response. Moreover, it has high power density with high proportion of torque to inertia in spite of small size drive. But, it produce torque ripple due to the motor inductance components in stator windings and back-EMF, when armature current is commutated. Therefore, it is difficult to apply the BLDCM to a precision servo drive system. In this paper is proposed to a new current control algorithm with using fourier series coefficients can minimize torque ripple due to the phase current commutation of BLDCM. Simulation and Experimental results prove the effectiveness the proposed algorithm through comparison with the conventional used unipolar PWM method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.86-88
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• 1994

In this paper, we present the design procedure and analysis the fundamental characteristics for Linear DC motor using permeance method and finite element method. Designed LDM is made of two permanent magnets, three iron core and amateur windings. For the design the LDM, first of all it is nessary to calculate the air gap flux density and thrust force, after that to determine core size, the numbers of winding turns, winding width, motor cross section area and losses in the coil. Also, we analysis the fundamental characteristics for implemented LDM according to proposed design procedure, and we find that the implemented LDM generated constant thrust force for costant current as long as iron of core is not saturated. Finally, we find that the proposed design procedure in this paper is effective to design and implementation of LDM.