• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.486-487
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• 2012

In this paper, novel three-port active power decoupling (APD) method for applying 250[W] micro-inverter. This type using third port for active power decoupling stores the surplus energy and supplies sufficient energy to grid. Conventional decoupling circuit is applied in single phase grid connected micro-inverter especially single-stage configuration like flyback-type DC-AC inverter. In this passive power decoupling method, electrolytic capacitor with large capacitance is needed for decoupling from constant DC power and instantaneous AC power. However the decoupling capacitor is replaced with film capacitor by using APD, thus the overall system can achieve smaller size and long lifespan. Proposed three-port flyback inverter is verified by design and simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.128.2-128
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• 2001

Since pulse energization can improve the performance of Electrostatic Precipitator(ESP) for high resistivity dusts, high voltage micro-pulse generators, 70kV 140usec duration pulses for instance, are commonly developed by LC resonance for most pulse powered ESPs. Consisting of discharge electrodes and collecting electrodes, ESP has its own capacitance like a capacitor. ESP's capacitance affects the LC resonance phenomenon with resonance inductor and capacitor of micro-pulse power supply, engineers should acquire the value of their ESP to design for proper power supply design. In this study, we describe the ESP's capacitance measuring device which has the same topology with our new developed micro-pulse power supply. In this microcontroller based capacitance measuring equipment, ESP's capacitance can be calculated easily through ...

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.04a
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• pp.65-91
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• 2003

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.242-243
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• 2013

This paper presents a voltage and frequency regulation of a Micro-grid using a Battery energy storage system (BESS) and super-capacitor (SPC). The control methods for the both BESS and SPC are proposed to improve the regulation performance and battery life span. The simulation results using the PSCAD/EMTDC are provided to show the effectiveness of the proposed control.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.247-248
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• 2006

Carbon nitride films were evaluated that they had many advantages for miniature micro-humidity-sensors using the standard CMOS technology humidity sensing properties and CV characteristics of the carbon nitride films have been investigated for fabricating one chip HUSFET(Humidity Sensitive Field Effect Transistor) humidity sensors Carbon nitride films were deposited on silicon substrate with meshed electrodes by reactive RF magnetron sputtering system. The capacitor-type humidity sensor revealed good humidity-impedance characteristics with a wide range of relative humidity changes, decreasing $254k{\Omega}$ to $16k{\Omega}$ according to increase of relative humidity between 5% ~ 95% and the films were very stable on the Si wafer. These results reveal that $CN_x$ thin films can be used for Si based or HUSFET structure one chip micro-humidity sensors.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.3
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• pp.110-116
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• 2020

Grains in the BaTiO₃, which is used for a dielectric layer in MLCC(Multi-Layer Ceramic Capacitor) are necessary to form core/shell structure for a stable TCC(Temperature Coefficient of Capacitance) behavior. The shell property has been deduced from the whole TCC behavior of core/shell structure due to its tiny size, ~ few ㎛. This study demonstrates the individual TCC behavior of the shell phase measured by micro-contact measurement in a temperature range between 35 and 135℃. Pt electrode pairs deposited on an enlarged core/shell structure in a diffusion couple sample made the measurement possible. As a result, the DPT (Diffusion Phase Transition) behavior of the shell phase was revealed as a different TCC behavior from that of the core: a broad peak with T_m at 65℃. This would be also useful experimental data for a modelling that depicts dielectric-temperature behavior of core/shell structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.85-92
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• 2002

In this study, we analyzed and experimented micro-strip line inductors and capacitors for a SAW duplexer, an important devise for mobile communication. For SAW duplexers, micro-strip line lumped elements must have small impedance values, below several tens of nH or several tens of pF, and a small area pattern. In this study, we performed theoretical analysis of flat line type, meander line type, and spiral line type inductors and interdigital capacitors on a LiTaO$_3$ Piezo-crystal. We proposed a measurement method to evaluate small values of lumped elements accurately with network analyzer. In experiments, we confirmed validity of the theoretical analysis method through fabrication and characterization of micro-strip line lumped elements. The analysis method in this paper can be applied to SAW duplexers well as other microwave devices.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2175-2184
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• 2009

This paper describes operational analysis results of the DC micro-grid using detailed model of distributed generation. Detailed model of wind power generation, photo-voltaic generation, fuel-cell generation was implemented with the user-defined model of PSCAD/EMTDC software that is coded with C-language. The operation analysis was carried out using PSCAD/EMTDC software, in which the power circuit is implemented by built-in model and the controller is modelled by user-defined model that is also coded with C-language. Various simulation results confirm that the DC micro-grid can operate without any problem in both the interconnected mode and the islanded mode. The operation analysis result confirms that the DC micro-grid make it feasible to provide power to the load stably. And it can be utilize to develop the actual system design and building.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.6
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• pp.31-38
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• 2013

A pulse driven atmospheric plasma jet controlled by external ballast capacitor is developed. Unlike the most commonly use DBD sources, the proposed device utilizes bare metal electrode. The discharge energy per pulse can precisely be determined by changing voltage and capacitance of the ballast capacitor. It is shown that the device can provide wide range of plasma, from stable glow mode to near arc state. Current-voltage waveforms, optical emission spectra and discharge images are investigated as a function of an injection energy. The OES shows that He and oxygen lines are increased as a function of the external ballast capacitor. Ozone and rotational temperature have similar tendency with a power consumption. The feeding gas is He and the applied DC voltage is from 400V to 800V when the gap distance is $500{\mu}m$.

• Journal of Power System Engineering
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• v.3 no.4
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• pp.57-62
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• 1999

The microaccelerometer using a tunnelling current effect concept has the potential of high performance, although it requires slightly complex signal-processing circuit for servo-system. The paddle of micro accelerometer is pulled to have the gap width of about 2nm which almost allows the flow tunnelling current. This paper demonstrates at capacitor of microaccelerometer the use of the coupled thermo-electric analysis for voltage, current, heat flux and Joule heating then tunnelling current flows. Two electrodes are applied to the microaccelerometer producing a unform difference of temperature gradient and electric potential between the paddle and the substrate.