• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1513-1520
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• 2009

Renewability and pollutant free energy source makes hydrogen energy popular rapidly. Hydrogen gas pressure which is after passing through reciprocating compressor part has high pulsation wave form. A unit, snubber is used as compressor components to reduce the harmful pulsation waveform and to remove the impurities in the hydrogen gas. An experiment has been conducted to investigate the pulsation reduction performance of a steel pipe used in snubber system. The amplitude of pressure reduction were varied from $0.054{\sim}0.321\;kPa$ for 10 hz to 60 hz motor speed. Compressor operation by motor with 10 to 60 hz were resulted in reduction of pressure pulsation from 16.415% to 35.151%. Pressure losses were varied from $0.001%{\sim}0.759%$, and pressure drop per centimeter of the steel pipe were varied from $0.0160{\sim}16.03\;Pa$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1055-1060
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• 2002

The noise and vibration of rolling piston-type compressors used in the most of the airconditional system is a serious and important problem occurred during turning on and off as well as during operating. To analyze the vibration occurred during turning on and oft, the vibration analysis of motor-compressor coupling is required. In this paper, through modeling of the motor, solving the force from the equations of motion of the moving parts and considering the stiffness of the rubber mounts, the analysis of vibration was performed.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.606-611
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• 2007

Pulsation is an inherent phenomenon in reciprocating compressors. It interacts with piping to cause vibrations and performance problems. Indiscriminately connecting to a compressor can be dangerous and cost money in the form of broken equipment and piping, poor performance, inaccurate metering, unwanted vibration, and sometimes noise. Piping connected to a compressor can materially affect the performance and response. To minimize these detrimental effects, reciprocating compressor system should be equipped by pulsation suppression system. This study discusses pressure pulsation phenomena occurred in a reciprocating compressor system. An experiment applied air compressor unit, as pulsating pressure generator, has been done. The compressor was connected sequentially to a snubber model and pressure tank. Sensor probes were placed on the inlet and outlet pipes of snubber. Compressor was driven by a motor controlled by a frequency regulator. The experiment was conducted by adjusting the regulator at 40Hz. General information about an internal gas flow can be achieved by numerical analysis approach. Information of the velocity, pressure and turbulence kinetic energy distribution are presented in this paper. Based on this result, the design improvement might be done.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.71-78
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• 2006

Thermodynamic irreversibility analysis of an air-to-water heat pump system is analyzed in this study. This analysis shows the distribution of irreversibilities(true losses in thermodynamic sense) through the system components and informs us of a potential improvements with the irreversibility factor decreases. The results show that the largest irreversibilities occur in the motor-compressor unit. The remaining irreversibilities are distributed relatively uniformly through the other parts including utilization system. The increase of performance can be attained through either the improvement of adiabatic efficiency of motor-compressor unit(${\eta}_{mc}$) or the reduction of temperature difference(${\Delta}T$). With the decrease of utilization temperature($T_u$) COPH also increases but the exergetic efficiency decreases. The increase of COPH of about 0.05 can be accomplished with 1K decrease of ${\Delta}T$ or $T_u$.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.122-127
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• 1999

In this paper, the power factor correction circuit using a parallel drive method is proposed so that the high power inverter air-conditioner with 3[hp] compressor motor may obtain the cost down and the improved performance. The adequate design porcedures are presented to reduce the material costs by eliminating the power factor imprving LC filter and derating output capacitor and inverter switches. Using the determined components. the proto-type circuit with 6[kW] power consumption is built and tested to verify the operation of the proposed circuit.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.712_713
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• 2009

This paper deals with the analysis on eddy current looses of high speed permanent magnet synchronous motor (PMSM) for turbo compressor according to voltage source driving. This paper presents analytical procedures for calculation of the eddy current losses using Poynting theorem. On the basis of the magnetic vector potential and a two-dimensional (2-D) cylindrical coordinate system, this paper derived analytical solutions of the eddy current looses using phase current analysis. The eddy current losses of each harmonic obtained by fast Fourier transform (FFT) analysis of phase current are with results obtained from finite-element method (FEM).

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.731-732
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• 2008

This paper deals with design and characteristics analysis of 7.5-kW, 60,000-rpm class permanent magnet synchronous motor for turbo compressor. In order to determine the design parameters of rotor, torque per rotor volume method is applied. And, to analyze the magnetic field distribution and estimate the electrical parameters such as back EMF constant, inductance and torque constant, electromagnetic transfer relations theorem is employed. We compare the characteristics analysis results of model designed by proposed method with those by nonlinear FEA. As a result of this, the design have been validated.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.50-54
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• 2007

In this paper, a dual-servo type VCM (Voice Coil Motor) for the measuring of nano-level displacement and small thrust is proposed and developed. The shape of VCM for improving the resolution of displacement and ensuring a large displacement are presented. The FEM (finite element method) is utilized to analyze the characteristics of VCM that produces linear driving thrust and satisfies the thrust that the measurement system requires. The Prototype is fabricated and an experiment is performed in order to measure displacement. As a result of simulation and testing, the proposed VCM shows the applicable possibility for a nano-level measurement system.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.684-686
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• 2003

Until recently, the 2-D FEA neglects the magnetic field fringing and end-leakage, it leads to the approach of a trial and error experimental design. Since 3-D FEA is investigated for exact side force analysis of Linear Motor for Linear compressor. For the 3-B FEA, ANSYS as commercial tool are used.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.211.1-211.1
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• 2008