• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.33-36
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• 2009

콘덴서는 유도성 부하의 늦은 역률 보상으로도 사용되며, 비선형 부하에서 발생하는 고조파를 저감하기 위해 리액터에 직렬로 연결하여 사용되기도 한다. 콘덴서는 전압이 증가할 경우 전류도 함께 증가하고, 주파수가 증가할 경우 콘덴서에 흐르는 전류가 증가하기 때문에 전류의 증가는 바로 열의 증가로 콘덴서 절연에 스트레스로 작용하여 고장의 원인을 제공할 수 있다. 본 연구에서는 콘덴서에 인가되는 전압의 크기와 주파수를 변화시킬 경우 콘덴서에서 발생하는 열을 열화상 카메라로 측정하여 외부 및 내부에서의 온도분포를 분석하였다. 측정결과 전압과 주파수가 증가할 경우 콘덴서에서 열이 매우 높게 분포함을 확인할 수 있었다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.76-77
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• 2011

태양광 발전 시스템에서 태양광 모듈은 일사량과 온도에 따라 출력특성이 변하고 비선형적인 특성을 지니고 있다. 따라서 최대전력 출력을 얻기 위해서는 컨버터에 의한 최대 전력점 추종제어가 필요하다. 특히 발전시스템에서 요구하는 전기적 특성을 맞추기 위해 다수의 태양모듈을 직병렬로 연결하여 구성하는데 있어서 그림자 혹은 일부 모듈이 정상작동하지 않아 미스매치 손실이 발생하게 된다. 본 연구에서는 미스매치 손실을 극복하는 최대전력점을 추종하는 제어알고리즘을 설계하였고 이를 시뮬레이션을 통해 검증하였다.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.149-154
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• 2000

The purpose of this study is to measure the compression temperature in cylinder by using the fine thermocouple. As for using the thermocouple, it's response time delay should be regarded, even if it is a fine one. So, the output of thermocouple needs some compensation. The compensation circuit, which consists of a differential and an adding circuit is used for the compensate the time lag. And the time constant of the compensation circuit is determined the time between the TDC and the maximum point of the thermocouple output. Using this compensation circuit, the compression temperature is investigated of the cylinder in the diesel engine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.109-113
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• 2013

In order to avoid the electrical fire, AFCI(Arc Fault Cirruit Interrupter) has been obligated to be adopted in the United States of America since 2002. AFCI using line resistor of neutral trace needs to compensate the variation of the line resistance by temperature variation. In this paper, the ASIC including the temperature compensation circuit is implemented. The proposed implementation is verified by showing the effectiveness of an electric and a temperature characteristics for Arc signals by simulation results.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.700-703
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• 2004

본 논문에서는 승압형 컨버터의 온/오프 스위칭 손실을 줄이기 위한 새로운 저손실 스너버 회로를 제안한다 제안하는 회로는 인덕터의 보조 권선을 통해 회로를 구성하며 부가되는 소자의 수가 작은 장점을 갖는다 제안하는 회로는 턴온 때에는 인덕터 보조 권선에 의해 스위치로 흐르는 전류의 상승을 제한하는 효과가 나타나므로 다이오드 역회복 전류에 의한 스위치 손실을 줄여준다. 동시에 턴오프시에는 스너버 회로를 통한 스위치 전압의 상승을 완만히 해주므로 역시 손실을 줄여준다. 본 논문에서는 1kW급의 단상 역률보상회로에 제안하는 회로를 구성하여 이의 동작을 검증하였다.

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.420-424
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• 1994

This paper presents an improved water level control scheme for Pressurized Water Reactor(PWR) Steam Generator(S/G) at the low power operation and transient states. To reduce fluctuations of the water level by the swell and shrink phenomena, the scheme adds feedforward terms considering S/G pressure and the feedwater temperature into the conventional proportional-integral feedback controller. The simulation results using the Compact Nuclear Simulator show that smaller level errors and much faster settling time than those of the conventional scheme can be obtained. The proposed algorithm is easily implementable and has a potential for the real applications.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1174-1177
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• 2012

In voltage measurement by using voltage divider with series resistors, error is generated caused by the variation of resistance. In order to reduce these errors, the hardware cost tends to increase in the previous works. In the proposed method, three resistors are used for the voltage divider of which the organization is adjusted by using switches. Three voltages are measured and the ratio of resistance is calculated based on the measured voltages. Since the resistance ratio is calculated by measuring voltages and additional hardware cost is minimal, the voltage can be measured with high accuracy and low cost. Experimental results show that the mean absolute error is 12.1 mV when the input voltage ranges from 5 V to 50 V.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.238-241
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• 1995

In this paper, a new Maximum Power Point Tractor (MPPT) using Fuzzy Controller is proposed to improve energy convention efficiency. Temperature compensation effect means the photovoltaic voltage is change in condition irradiation, temperature and etc. Fuzzy algorithm is applied to control Boost MPPT converter by Temperature compensation effect. Temperature compensation range is $-40\sim+100^{\circ}C$.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.376-378
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• 1995

A method is presented for the design and fabrication of the temperature compensation circuits on the Clark electrodes for measuring the dissolved oxygen(DO) concentration. The discussion includes a method of the sensor interface circuits for the DO sensor. Typical polarograms for the DO probes under test using this sensor circuits are presented. High accuracy over 99 % of the I to V conversion using the proposed circuit is verified. Temperature dependence for the test DO probe is well compensated automatically using the thermistor($2k\Omega,\;25^{\circ}C$) in series with correction resistor in the feedback loop of the op-amp circuit in the temperature range of the 0-50$^{\circ}C$.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.4
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• pp.8-14
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• 2016

In this study, the effects of prediction and reset control of outdoor air temperature on energy consumption for central heating system are researched by using TRNSYS program package, and the control performances with the suggested methods of prediction and reset control of outdoor air temperature are compared with the existing ones. As a result, the value of coefficient of determination $R^2$ for the predicted outdoor temperatures is improved and the suggested control method shows maximum 21.8% energy saving in comparison with existing control ones.