• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.588-590
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• 1996

An AC induction motor or constant speed characteristics has been widely used as power source because of simple structure and low maintenance cost in industrial field. The variable frequency AC source with a conventional inverter which is composed or power semi-conductors and drive systems contains much noises in sine wave current due to high speed switching or direct current. In this paper, the low pass LC filter for a variable speed induction motor driven by a full bridge inverter is introduced to solve EMI problem originated by much noise current. The modified LC filter based on the 3rd order Butterworth LC filter is used for the computer simulations and real experiments. The characteristics or proposed LC filter are investigated through FET analysis.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.232-235
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• 2001

This paper presents a circuit of the quasi-resonant DC link to achieve soft-switching three phase inverter using intelligent IGBT power module. The soft-switching operation in this circuit is confirmed simulation and experimental results. Its conductive noise is measured for electrical AC motor drive as compared with that of the conventional hard switching inverter.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.531-536
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• 1991

This paper describes a POWER MOSFET inverter suitable for medium frequency induction heating applications. A series scheme is employed, which is operated at zero phase of the resonant load by PLL control. This ensures maximum power transfer, good efficiency, low EMI noise and reliable operation. Circuit configuration and performance are discussed and design criteria are given. Implementation of a prototype rated at 5KW, $100{\sim}300KHz$ is discribed and experimental results are given.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.2
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• pp.84-89
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• 2013

In this paper, we propose interface circuits for reducing power consumption and EMI when sequences of data from LCD controller to LCD driver IC by transmitting two bit data during one clock period. The proposed circuits are operated in current mode, which is different from conventional voltage-mode signaling techniques, and also employ threshold technique of Modified-LVDS(Low Voltage Differential Signaling) method. We have simulated the proposed circuits using H-SPICE tool for performance analysis of the proposed method. The simulation results show that the proposed circuits provide a faster transmission speed and stronger noise immunity than the conventional LVDS circuits. It might be suitable for the real-time transmission of huge image data in LCD system.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1108-1113
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• 1992

In this paper, the high frequency twin resonant inverter using MOSFET is presented. The output control is excellent and the EMI noise is reduced, because the output appear as the vector sum of current in each unit inverter. The output voltage and the output current of the inverter are controlled by PLL. In this paper, the principle of the twin resonant method is described. And computer simulations and experimental results are shown.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.3
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• pp.343-352
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• 1998

Higher frequency of energy transfer or at least energy conversion has to be used in order to reduce the size of inductors and capacitors required in the power supplies. Conventional PWM switching-mode power supplies have a limitation of operating frequency due to switching losses in the switching transistors and rectifier diodes. Means of reducing switching losses have been developed for high-frequency resonant amplifiers or more exactly dc/ac inverters. Because of smooth current and voltage waveforms resonant convertesrs havelower device switching losses and stresses lower electromagnetic interference(EMI) and lower noise than PWM converters. Therefore in this paper design equations of Classs E resonant low dv/dt rectifier with a series resonant capacitor drived using Fourier series techniques. The theory is compared with simulation results obtained for the rectifier operating at 10[MHz] ac input and 5[V] coutput.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1561-1563
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• 2001

In this paper, an novel optical measuring system based on the electro-optic effect has been proposed and realized using Pockels cell with a view to detecting partial discharge taking place at the needle plane electrode. This system has the following advantages ; nonmetallic probe sensor, immune to external EMI noise and broad band response of the Pockels cell from DC to GHz. And also it is constructed by He-Ne laser, optical fiber, $LiNbO_3$ Pockels cell, photo detector, grin lens, oscilloscope and PC. The characteristics of the developed prototype sensor are investigated under AC and corona discharges.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.324-327
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• 2002

For the characterization of arbitrary shaped printed circuit board, lossy transmission line grid model based on SPICE netlist and analytical plane model based on the segmentation method are proposed in this paper. Two methods are compared with an arbitrary shaped power/ground plane. Furthermore, design considerations for the complete power distribution network structure are discussed to ensure the maximum value of the PDN impedance is low enough across the desired frequency range and to guide decoupling capacitor selection.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.340-343
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• 2002

Electromagnetic(EM) radiation problems and their possible solutions are addressed in this paper for the split power plane of high-speed digital systems. Stitching and decoupling capacitors are proved to be very effective fur reducing signal noise, ground bounce as well as electromagnetic radiation from the split power plane. Simulations based on 3D-Finite Difference Time Domain (FDTD) method are utilized for the analysis of practical high frequency multi-layered PC main board

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.81-88
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• 2003

CISPR has published the limits on the noises emitting from power lines and signal lines. But different measurement environment and measurement methods are used in every countries. This difference causes much confusion in understanding the results measured by different test laboratories. In this paper, we measure EMI noise using the absorbing clamp method that takes short measurement time and is described in CISPR 13, 14-1, 16-2. We analyze the cause of the difference of measurement results and propose the method for improving the uncertainty