• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.150-152
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• 2004

The number of layers in rigid PCB(printed circuit board) is restricted, so the number of components can be embedded in module is restricted also. But using flexible multilayer PCB, the layers over than 7 can be evaluated. In this study, to verify the possibility of application of flexible multilayer PCB to RF modules, multilayered embedded capacitor is fabricated and analyzed. The characteristics of embedded capacitor is analyzed and compared to that of MLCC and LTCC capacitor. Embedded capacitor has better electrical features than MLCC and compatible one to LTCC capacitor.

• 접착 및 계면
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• 제25권3호
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• pp.100-105
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• 2024

유연 캐패시터는 두 개의 전극 사이에 전기적 에너지를 저장할 수 있으며 동시에 유연성을 갖고 있는 장치로 전자 회로의 중요한 구성요소이다. 이러한 캐패시터는 디스플레이 부품 등 다양한 분야로의 응용을 위해 전극 패터닝이 필수적이며, 패터닝 공정으로는 포토리소그래피 기술이 주로 이용된다. 포토리소그래피 기술은 기술 성숙도가 높다는 장점을 가지는 반면, 값비싼 공정 장비를 필요로 하고 환경에 유해하며 두 개의 전극을 개별적으로 패터닝해야 하므로 공정비용이 높다는 단점을 갖는다. 본 연구에서는 접착력 제어 기반의 비광학적 패터닝 기술을 이용하여 캐패시터의 상부전극과 하부전극을 동시에 패터닝하는 연구를 진행하였으며, 이를 기반으로 유연 캐패시터를 제작하고 외부응력 및 나노소재 첨가가 캐패시터의 특성에 미치는 영향을 연구하였다. 결과적으로 단일 공정 상·하부 전극 동시 패터닝 기술을 기반으로 캐패시터 제작 공정 수를 상당히 감소시킬 수 있었으며, 무기계 나노소재 첨가를 통해 캐패시터의 특성을 향상시키고 다양한 응력에 유연성을 갖는 유연 캐패시터를 제작할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.428-435
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• 2013

Flexible AC Transmission System (FACTS) application study on enhancing the flexibility of AC power system has continued to make progress. A thyristor-controlled series capacitor (TCSC) is a useful FACTS device that can control the power flow by adjusting line impedances and minimize the loss of power flow and voltage drop in a transmission system by adjusting line impedances. Reduced power flow loss leads to increased loadability, low system loss, and improved stability of the power system. This study proposes the optimal location and compensation rate method for TCSCs, by considering both the power system loss and voltage drop of transmission systems. The proposed method applies a multi-objective function consisting of a minimizing function for power flow loss and voltage drop. The effectiveness of the proposed method is demonstrated using IEEE 14- and a 30-bus system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.705-706
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• 2010

• 한국전자파학회논문지
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• 제22권2호
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• pp.236-244
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• 2011

본 논문에서는, Glass 안테나의 특성과 휴대성 및 제작상의 장점이 있는 다이폴 형태의 Flexible T-DMB 안테나를 제안하였다. 차량의 전면 유리 최외각에 위치하는 안테나를 구현하기 위하여 차체의 영향에 따른 안테나의 특성과 안테나의 부착 위치에 따라 달라지는 안테나 특성을 고려하여 급전 선로 사이에 매칭 회로를 추가하여 안테나의 입력 정합 특성을 높였다. 차량의 전면 유리에서의 실험 결과, T-DMB(174~216 MHz) 대역에서 안테나의 입력 반사 손실은 -6 dB 이하를 기준으로 모두 만족하였으며, 위치 변화에도 T-DMB 대역을 만족하였다.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.627-634
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• 2018

Gallium-based liquid metal, e.g., eutectic gallium-indium (EGaIn), is highly attractive as an electrode material for flexible and stretchable devices. On the liquid metal, oxide layer is spontaneously formed, which has a wide band-gap, and therefore is electrically insulating. In this paper, we fabricate a capacitor based on eutectic gallium-indium (EGaIn) liquid metal and investigate its cyclic voltammetry (CV) behavior. The EGaIn capacitor is composed of two EGaIn electrodes and electrolyte. CV curves reveal that the EGaIn capacitor shows the behavior of electric double-layer capacitors (EDLC), where the oxide layers on the EGaIn electrodes serves as the dielectric layer of EDLC. The oxide thicker than the spontaneously-formed native oxide decreases the capacitance of the EGaIn capacitor, due to increased voltage loss across the oxide layer. The EGaIn capacitor without oxide layer exhibits unstable CV curves during the repeated cycles, where self-repair characteristic of the oxide was observed. Finally, the electrolyte concentration is optimized by comparing the CV curves at various electrolyte concentrations.

• 전력전자학회논문지
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• 제9권2호
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• pp.150-157
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• 2004

본 논문에서는 아날로그형 전력 계통 시뮬레이터에 적용하고자 개발 중인 TCSC(Thyristor Controlled Series Capacitor) 시뮬레이터 시스템 제어기의 하드웨어와 소프트웨어 구성에 대하여 제시하고자 한다. 본 연구에서 개발하고자하는 TCSC 시스템의 제어기는 기존의 전력 계통 시뮬레이터의 여러 제어기들과 통합되어 전력 시스템의 특성을 제어하는 장치이기 때문에 제어기는 전력 시스템의 각종 주요 파라메터를 실시간으로 통신할 수 있어야 하며 주어진 시간 내에 제어 기능을 수행할 수 있어야 한다. 따라서, 이러한 요구 조건을 만족시키기 위해서는 제어기 하드웨어의 설계와 구성이 매우 중요하다 본 논문에서는 TCSC 시스템의 복합적인 기능 수행을 위한 제어기 하드웨어와 소프트웨어 구조에 대하여 제시하고자 한다. TSCS 제어기는 고속 부동 소수 연산이 가능한 DSP(Digital Signal Processor) 플랫폼과 실시간 RTOS(Real Time Operating System)로 구성되어 있다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.163.2-163.2
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• 2010

We developed a simple method to synthesis a nitrogen doped graphene, nitrogen plasma treated graphene (NPG) sheets thought nitrogen plasma etching of graphene oxide (GO). X-ray photo electron spectroscopy (XPS) study of NPG sheets treated at various plasma conditions reveal that N-doping is classified to 3 kinds of binding configurations. The nitrogen doping concentration is at least 1.5 at % and up to 3 at% with changing of ratio of nitrogen configuration in NPG. Our group demonstrate ultracapacitor with high capacity and extremely durable using a NPG sheets that are comparable to pristine graphene supercapacitor, and pseudocapacitor using polymer and metal oxide with redox reaction, capacitance that are three-times higher, and a cycle life that are extremely stable. We also realized flexible capacitor by using the paper electrode that are coated by NPG sheets. NPG paper capacitor presented almost same performance compare with NPG on a metal substrate, and durability is much more enhanced than that. To additionally explain that how different kind of atoms in graphene layers can act as the ion absorption sites, we simulated the binding energy between nitrogen in graphene layer and ions in electrolyte. Increasing the energy density and long cycle life of ultracapacitor will enable them to compete with batteries and conventional capacitors in number of applications.

• 대한전기학회논문지:전력기술부문A
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• 제54권4호
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• pp.159-164
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• 2005

Various compensators are installed into the power system to operate the system economically and stably by maximizing the availability of utilities and power transmission capability. Fixed Capacitor(FC), Mechanical Switched Capacitor(MSC), and FACTS(Flexible AC Transmission Systems) are used to regulate voltage and power flow of the system. When a disturbance occurs in the power system, the Fixed Capacitor operates dependently on the voltage of the power system and cannot change the amount of installation automatically. But compared to other equipment, the Fixed Capacitor is more economical due to its low cost. Since MSC can change the amount of installation according to the state of the power system, operates more effectively than the Fixed Capacitor. FACTS have fast dynamic performance for the transient condition, but the cost is high. Therefore, it is needed to develop an optimized installation planning for the reactive power compensators by considering their dynamic performance and cost. In this paper, an optimized compensator combination and the proposed scheme is proposed and it is applied to KEPCO system in order to show its capabilities.

• 한국염색가공학회지
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• 제31권2호
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• pp.65-76
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• 2019

A multi-point touch input sensor having different sizes or different capacitance touch points connected by only one pair of signal transmission lines was fabricated using a polyimide film coated with a thin copper plate. The capacitance increases with the decrease in the number of sheets of fabric spacers placed between the two sheets of the polyimide film. Therefore, the touch input sensor could be manufactured without fabric spacers, which was possible by the action of the polyimide film as a dielectric material in the capacitor. On the multi-point touch sensor, higher capacitance was obtained when pressing wider-area touch points with 10mm to 25mm diameter on average. However, the capacitance of a system comprising two sheets of touch sensors was considerably low, causing a serious overlap of the capacitance values according to the data collected from the reliability test. Although the capacitance values could be increased by stacking several sheets of touch sensors, the overlap of data was still observed. After reducing the size of all touch points to 10mm and stacking up to eight sheets of sensors, reliable and consistent capacitance data was obtained. Five different capacitance signals could be induced in the sensors by pushing touch points simultaneously.