• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.595-601
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• 2003

For a control of CPS(Contactless Power Supply), the paper deals with the results which are simulated by a equivalent electric circuit on the LIPT(Linear Inductive Power Transmission). In order to control the CPS, the output values is handled with the driving frequency according to the change of a load. The method that controls the driving frequency for adjusting the output power is reasonable to be applied to the controller. But, when the driving frequency meets the resonant frequency and passes, it lead to a serious problem. Therefore, the controlled region of the driving frequency has to be predicted and determined by the simulation of a electric circuit.

• 한국시스템다이내믹스연구
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• 제6권2호
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• pp.25-35
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• 2005

This paper describes the mechanism for new investment to appear in waves of boom and bust causing alternative periods of over and under supply of electricity in Korean market. A system dynamics model was developed to describe the dynamic behavior of new investment in Korean market. The simulation results show the boom and bust cycle in the new investments. When the market price is high, investors decide to build new power plants. However, it takes some delay time to complete new power plants. When the new power plants are being added into the grid, the supply increases and the wholesale price begins to decrease. This causes the cancellation of new power plant or delay the construction. This mechanism causes the boom and bust cycle in new investment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.22-24
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• 2008

Construction of wind power plant is rapidly increasing since Jeju is known as the most suitable regarding wind power plants in Korea. But implementing wind power generation inevitably introduces new challenges due to its intermittent nature. In the paper, it is introduced the influence analysis and Han-Kyung wind power plants contribution on Jeju power system.

• 디지털콘텐츠학회 논문지
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• 제17권6호
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• pp.499-507
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• 2016

사물 간의 인터넷을 통하여 정보를 주고받는 사물인터넷 시대가 열리고 있다. 최근 전력 수요가 급증하면서 기존 공급 위주의 전력에너지 정책 패러다임이 변화하고 있다. 사물인터넷 기술이 발전함에 따라 기존 전력망에 ICT를 융합시켜, 전력 디바이스 및 운영 시스템의 지능화를 가속화시킬 것이다. 전력망에 사물인터넷이 접목되어 개방화함에 따라 국가 전력망에 대한 사이버 위협 및 공격에 대한 우려가 증대되고 있다. 본 논문에서는 기존 사물인터넷에서의 보안 위협을 분석하고 전력산업 사물인터넷에서의 보안 취약점과 보안 요구사항 및 보안 기술을 제시하고자 한다.

• 조명전기설비학회논문지
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• 제29권2호
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• pp.19-26
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• 2015

This paper presents design, fabrication, and performance evaluation of a high voltage power supply for Carbon Nano Tube-based planar light sources. The proposed power supply employs an LLC resonant half-bridge converter and a sixfold voltage-multiplying rectifier. Steady-state characteristics of the voltage-multiplying rectifier are analyzed and used to derive the input-to-output voltage conversion ratio of the power supply. The input-to-output frequency response characteristics of the LLC tank circuit are analyzed and utilized in designing a proto-type power supply which produces a 15 KV output using a 400 V input source. The high-voltage transformer is fabricated using a sectional bobbin structure with an epoxy impregnation, in order to provide sufficient insulation for high voltage operations. The performance of the proposed power supply is confirmed with stable and reliable operations at the 15 KV output from no load to nominal load conditions. The proposed power supply is well suited as an electric ballast required stable operations of Carbon Nano Tube-based planar light sources.

• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.490-498
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• 2019

The intermittent electric power supply of renewable energy can have extremely negative effect on power grid, so long-term and large-scale storage for energy released from renewable energy source is required for ensuring a stable supply of electric power. Power to gas which can convert and store the surplus electric power as hydrogen through water electrolysis is being actively studied in response to increasing supply of renewable energy. In this paper, we proposed the novel concept of hydrogen liquefaction process combined with pre-cooling process using the liquid air. It is that hydrogen converted from surplus electric power of renewable energy was liquefied through the hydrogen liquefaction process and vaporization heat of liquid hydrogen was conversely recovered to liquid air from ambient air. Moreover, Comparisons of specific energy consumption (kWh/kg) saved for using the liquid air pre-cooling was quantitatively conducted through the performance analysis. Consequently, about 12% of specific energy consumption of hydrogen liquefaction process was reduced with introducing liquid air for pre-cooling and optimal design point of helium Brayton cycle was identified by sensitivity analysis on change of compression/expansion ratio.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1192-1195
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• 2002

In this paper, we propose Low-Power Receiver circuits for a wireless communication system using ASK signal. Their structures are suitable for low supply current. The proposed circuits are designed and simulated by Spectre using 0.8m CMOS process parameters, and operate with supply current below 1.5${\mu}\textrm{A}$.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.730-734
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• 2007

National projects on renewable energy and new energy are driven more actively than ever in many countries for the exhaustion of fossil fuel energy from the turn of the century. Such activities began to spread out in railway industry with centering around west European countries. Electric energy is generated on the hybrid vehicle itself, which contributes to reduction of the cost for construction of the infrastructure required for the supply of electric power. Hybrid tram is mainly composed of propulsion system to control electric energy, automatic guidance system to control steering and operation, and central vehicle unit to control and monitor major electronic devices. Generation and supply of electric power are made by the combination of engine generator and battery, or fuel cell and super capacitor.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.255-256
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• 2006

A wind power plant is one of the competitive and effective energy among the regulated 13 renewable energies, especially for the seashore and island. This study is focused on the possibility of wind power plant as a on-site electric power supply system for the common residential building in Youngdo, Busan. The following show the results of this study. 26 apartments' monthly electric power consumptions are surveyed and monthly variations are stable comparing to the metropolitan. With the wind speed measured in Youngdo island and wind power plant efficiency data, the simulation is conducted and the result shows that 35 wind power units are satisfied with full electric power load for all the common residential buildings in Youngdo island.

• Journal of Power Electronics
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• 제17권3호
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• pp.788-797
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• 2017

The power quality of AC electric railways has become an issue worthy of more and more concern. Many active compensators based on power converters have been proposed, but with complex transformers or coupled branches. This paper presents a single-phase cascaded H-bridge multilevel active power filter (APF), which can directly connect to the 27.5-kV power supplies to deal with power quality problems. According to field measured data, the load characteristics are analyzed, and the system configuration and control system are designed based on the load characteristic analysis. Finally, simulation and experimental results verify the effectiveness of the proposed APF system, considering some problems such as the supply voltage fluctuations and transient inrush currents in AC electric railway systems.