• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2156-2159
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• 2001

발전소 보일러 제어시스템 관련 기술은 분산처리 소프트웨어 기술, 네트워크기술, MMI(Man Machine Interface) 기술, 실시간 처리기술, 데이터베이스 기술, 하드웨어 개발기술 등을 총 망라하는 복합기술로써, 선진국들이 기술이전을 기피하는 고급기술이다. 현재 국내에서 사용하고 있는 발전소 보일러 제어시스템은 전부가 Bailey, ABB, Siemens, Westinghouse 사 등의 외국설비로써 보일러 본체와 일괄계약형태로 제어시스템 전체가 외국회사의 설계에 의해서 도입 설치되어 운용되고 있다. 이러한 상황에서 국산 제어시스템의 개발기술 확보와 기술자립 차원에서 오래된 아날로그 제어시스템을 디지털 분산제어시스템으로의 개체작업에 국산 개발 제어시스템을 중용량 석탄화력발전소에 최초로 실용화 적용하고 그 적용사례를 본 논문에서 소개한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.5
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• pp.739-746
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• 1994

This paper present an efficient methodology to solve the unit commitment problem for large scaled power system which involves various type of generation. We introduce the global optimization approach to coordinate the thermal type, hydro type and pumped storage type generation. To overcome the shortcomings in dynamic programming for thermal unit commitment, an improved heurisitic method using lambda(λ) was proposed, Hydro and pumped type allocation was Solved by analytical approach using λ which exculde undisirable iteration for satisfying the energy usage constraints. The case studies for proposed algorithm are proven by sample system and KEPCO practical system, which produced very resonable both computing requirements and convergency.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.138-145
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• 2009

A suspended membrane micro fluidic heat flux sensor that is able to measure the heat flow rate was designed and fabricated by a complementary-metal-oxide-semiconductor-compatible process. The combination of a thirty-junction gold and nickel thermoelectric sensor with an ultralow noise preamplifier, low pass filter, and lock-in amp has enabled the resolution of 50 nW power and provides the sensitivity of $11.4\;mV/{\mu}W$. The heater modulation method was used to eliminate low frequency noises from sensor output. It is measured with various heat flux fluid of DI-water to test as micro fluidic application. In order to estimate the heat generation of samples from the output measurement of a micro fluidic heat-flux sensor, a methodology for modeling and simulating electro-thermal behavior in the micro fluidic heat-flux sensor with integrated electronic circuit is presented and validated. The electro-thermal model was constructed by using system dynamics, particularly the bond graph. The electro-thermal system model in which the thermal and the electrical domain are coupled expresses the heat generation of samples converts thermal input to electrical output. The proposed electro-thermal system model shows good agreement with measured output voltage response in transient state and steady-state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.51-51
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• 2009

In this paper, we proposed GaN trench Static Induction Transistor(SIT). Because The compound semiconductor had superior thermal characteristics, GaN and SiC power devices is next generation power semiconductor devices. We carried out modeling of GaN SIT with 2-D device and process simulator. As a result of modeling, we obtained 340V breakdown voltage. The channel thickness was 3um and the channel doping concentration is 1e17cm-3. And we carried out thermal characteristics, too.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1018-1022
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• 2009

In this paper, we proposed GaN trench Static Induction Transistor(SIT). Because The compound semiconductor had superior thermal characteristics, GaN and SiC power devices is next generation power semiconductor devices. We carried out modeling of GaN SIT with 2-D device and process simulator. As a result of modeling, we obtained 340 V breakdown voltage. The channel thickness was 3 urn and the channel doping concentration is $1e17\;cm^{-3}$. And we carried out thermal characteristics, too.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.180-183
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• 2006

As a final step for developing a small-scale solar thermal power generation technology, a demonstration project for a dish-stirling power system has been carried out by KIER. During the two years project period, 10kW solar-only power system was built in Jinhae city and successful solar operations were demonstrated. In this paper an example of typical clean day operation and analysis results was introduced.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.225-231
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• 2004

Scroll compressor has been used extensively for refrigeration since the early 1980's for its improved efficiency, greater reliability, smoother operation, lower noise and vibration. And also, nowadays, the scroll mechanism is used for expander even though in niche market yet. But scroll expander has not been used for high-temperature and high-pressure gas, because the continuous expansion of the gas causes a wide range of temperature distribution over the whole scroll wrap that leads to differential thermal expansion of scroll elements, which results in system vibrations, noise and efficiency losses. For the scroll expander to produce power more efficiently, all of radial and radial clearances between scroll wrap must be the same. In order to reduce differential thermal expansion in addition to improvements in thermal efficiency and specific power, we propose a scroll expander with heating structure. Heat-pipe heating structure is considered as the most effective method to heat the scroll expander at a uniform temperature. This paper includes some results of preliminary study of the scroll expander with heating structure and proposals of their systems for power generation and refrigeration.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1495-1504
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• 2021

An ultra-compact binary power generation plant converts thermal energy into electric power using temperature difference between heat source and cooling source. In the actual power generation environment, the characteristic value of the plant changes due to any negative effects such as environmental condition or corrosion of related equipment. If the characteristic value of the plant changes, it may lead to unstable output of the turbine in a conventional PID control system with fixed PID parameters. A Neuro PID control system based on Neural Network adaptively to adjust the PID parameters according to the change in the characteristic value of the plant is proposed in this paper. Discrete-time transfer function models to represent the dynamic characteristics near the operating point of the investigated plant are deduced, and a design strategy of the proposed control system is described. The proposed Neuro PID control system is compared with the conventional PID control system, and its effectiveness is demonstrated through the simulation results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.1
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• pp.1-9
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• 2018

Thermal performance of a heat sink for an inverter power stack was analyzed in terms of array and installation location of an Insulated Gate Bipolar Transistor (IGBT). Thermal flow around the heat sink was calculated with a numerical model that could simulate forced convection. Thermal performance was calculated depending on the array and location of high- and low-power IGBTs considering the maximum temperature of IGBT. The optimum array and installation location were found and causes were analyzed based on results of numerical analysis. For the numerical analysis, experiment design considered the installation location of IGBT, ratio of heat generation rates of high- and low-power IGBTs, and velocity of the inlet air as design variables. Based on numerical results, a correlation that could calculate thermal performance of the heat sink was suggested and the maximum temperature of the IGBT could be predicted depending on the installation method.

• The Journal of the Acoustical Society of Korea
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• v.29 no.8
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• pp.491-496
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• 2010

Thermoacoustic power generation by a spiral heater in the Rijke tube was analyzed numerically. In the analysis, variables were normalized by the angular frequency of the sound and the thermal diffusivity of the air. The effect of the heater wire diameter d, the spacing between wires P-d, and the air-current velocity $U_0$, upon the power generation was obtained and discussed. When the spacing is broad enough, the normalized velocity is $U_0{\approx}0.8$ and the diameter is $d{\approx}4$ for the maximum power generation. With decrease of the spacing, however, the power generation increases more than 5 times and becomes maximum around $d{\approx}2$, $P-d{\approx}3$. And the velocity $U_0{\approx}0.8$ for the maximum power generation is almost independent of the wire spacing.