• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.53-55
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• 1995

This paper presents the characteristics of linear induction motors fed by a voltage source PWM inverter. In the calculation, 2D finite element method is used considering the movement by moving mesh. Integro-differential approach is adopted for the copper loss calculation considering the skin effect.

• Journal of the Korean Institute of Telematics and Electronics
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• v.5 no.3
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• pp.25-30
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• 1968

The characteristics of single mesh discharge circiut for Xenon flashlamp has been analysised in detail. Since flashlamp voltage characteristics is linear in time, though nonlinear in current, the nonliear differential equation , for this system has beens solved by the analog computer. Also for given lamp type, energy input, pulse duration, and pulse shape factor, the inductance, capacatince and operating voltage were discussed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.259-265
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• 2004

No matter how well the equally spaced grounding grid is designed, there are questions keep rising, such as leakage of current from comer conductor, high voltage of touch voltage in corners of grid than in center, and high material cost for grounding grid. The best-fitted design for unequally spaced grounding grid is a part that must be considered. Explain advantages of unequally spaced grounding grid and lead formula by dividing the number of grid division, j, into 20, instead of 7. Then present $D_{ij}$, which is optimum rate for unequally spaced grounding grid and verify safety and economy of the unequally spaced grounding grid by computer simulation with a poly-nominal function form.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.432-435
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• 1989

This paper presents an algorithm for electric field analysis which is essential to insulation design of extra-high voltage oil-filled cable accessories using finite element method. Governing equation is induced by electromagnetic equation. Variational method is adopted for FEN formulation. Automatic mesh generation which saves time and labor is introduced for the input data. The application results of proposed algorithms were used for insulation design to develop 345kV cable joint.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.245-249
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• 1999

A new type of nonthermal plasma reactor utilizing ferroelectric pellets is proposed to generate nonthermal plasma efficiently, which is used for simultaneous control of various pollutant gases. Electric charges stored on ferroelctric pellets by corona discharge between a corona tip and a mesh electrode provide partial electrical discharges among ferroelectric pellets. These partial electrical discharges can enhance partial discharges around the surface of ferroelectric pellets. This method utilizes wide reacting area of ferroelectric pellets and partial discharge. Positive and negative dc voltage are applied to the corona tip to generate partial discharges, and corona currents are estimated to investigate charge storage on ferroelectric pellets as function of time and charge relaxation time constants of ferroelectric pellects. As a result, charge relaxationtime, dielectric constants of ferroelectric pellets, polarity of applied voltage and applied time influence partial discharges among ferroelectric pellect.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3008-3020
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• 1994

Condensation heat transfer on a single horizontal tube with electric fields (Electro-Hydro-Dynamics, (EHD)) has been studied experimentally. Results are presented for EHD enhanced condensation of R-113 on a single horizontal tube using several electrode geometries. Especially, its attention was focused on the effects of electrode geometry, electric field strength and the gap of the electrode. In this study, single wire, helical, ring and mesh electrode were used. The range of the imposed voltage was 0~20 kV. As the voltage was increased the surface of liquid became an unstable wave, stream jet, liquid column and then liquid extraction in sequence. Among the various kinds of electrodes, the single wire electrode is suitable for practical application.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2071-2073
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• 2000

Grounding electrode design is an important part in lightning protection, and the limit of hazardous voltages (step and touch voltages) below the permissible voltage for human body has been the main goal of grounding electrode design. In this paper, the grounding electrode for the reduction of hazardous voltages was designed and evaluated newly. It was known that the inclined auxiliary grounding conductors installed outside the grounding mesh grid are very effective to reduce the step and touch voltages.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.30-34
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• 2005

This paper describes the design and manufacturing of a focused-ion-beam machining system which can make small features of nano size. We use a SIMION simulator in order to obtain the design data of an ion column. The simulation result shows that the focal length of ion beam decreases as the applied voltage of object lens increases. Finally, we obtained the good images of a mesh of 50 micrometers by using the adjustment of applied voltage, acceleration power, and dimension of each elements.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.37-42
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• 2006

The effect of arc like streamer discharge is investigated on the hydrogen generation using the multineedle-plate electrode geometry plasma realtor(MPER) and the needle-plate electrode geometry plasma reactor(NPER). In order to restrict waves at the water surface when the high voltage applied, two kinds of the insulator such as the rectangular mesh or the hole mesh type are installed under the water surface. The discharge assistant of the two type(the saw type and the $TiO_2$ pellet type) was placed under the water surface to investigate the effect of the water surface conditions. The experimental results are compared in case of the reactor with and without the discharge assistant on the water surface.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.465-470
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• 2005

In this paper. an experimental study, for method of increasing the efficiency of electrostatic precipitator for the collection of submicron-sized particles has been studied. All AC electric field was used to induce agglomeration of bipolory charged Particles. .4 bipolar AC-agglomeration system. consisted with a multineedle-mesh discharge system with a control grid, was proposed and investigated. Systematic experiments were carried out to investigate the agglomeration ratio of the AC-agglomeration system as a function of the different grid spacings and grid resistances for the submicron particles generated from liquid prorhane gas burning. The agglomeration ratios, which indicate the particle numbers before and after agglomeration of the test particles in number concentration base, were found to be 0.87, 1.80, 3.86, 9.50 and, 11.00 times for the particle sizes of 0.3. 0.5, 0.7, 1.0, and 2.0$\mu$m at applied voltage of 3.5kV, respectively which showed that the fine particle numbers were decreased while the larger particle numbers were increase greatly.