• 한국전기전자재료학회논문지
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• 제34권2호
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• pp.136-141
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• 2021

Heating cables, widely used in office buildings, factories, streets and railways, deteriorate in electrical insulation during operation. The insulation deterioration of heating cables leads to electric discharges that can cause electrical fires. With this background, this paper dealt with a condition monitoring technique for heating cables by the analysis of discharge signals to prevent electrical fires. Insulation deterioration was simulated using an arc generator specified in UL1699 under AC operation, and the characteristic and propagation of discharge signals were analyzed on a 100 meter-long heating cable. Discharge signals produced by insulation deterioration were detected as a voltage pulse because they are as small as a few mV and they are attenuated through propagation path. The frequency spectrum of discharge signals mainly existed in the range from 70 kHz to 110 kHz, and the maximum attenuation of the signal was 84.8% at 100 meters away from the discharge point. Based on the experimental results, a monitoring device, which is composed of a high pass filter with the cut-off frequency of 70 kHz, a comparator, a wave shaper and a microprocessor, was designed and fabricated. Also, an algorithm was designed to discriminate the discharge signal in the presence of noise, compared with the pulse repetition period and the number of pulse counts per 100ms. In the experiment, the result showed that the prototype monitoring device could detect and discriminate the discharge signals produced at every discharge point on a heating cable.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2357-2364
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• 2011

Diesel locomotive operates the generator with the power from the diesel engine, and it consists of the typical serial-hybrid system which operates the train wheels by converting its generated electric energy into the torque of DC (or AC) motor. However, the technology of locomotives is only focused on trains' controlling power generation mechanism. Hence, it is a current issue that the efficiency of its engine and its generator is relatively lower than that of auto vehicles'. Particularly, since there are no proper equipment to measure the amount of fuel which is essentially necessary for the efficient use of fuel, it is not easy to confirm the instant amount of fuel use as well as the exact average fuel consumption per an hour. Due to those difficulties, it is urgent to develop the device that measures the fuel consumption. Plus, this use of the developed measuring device allows the various and useful analysis relating to the fuel consumption, and this could lead to establishing the efficient driving pattern regarding to fuel saving. This device consists of two flux (fuel level) measuring censors, MCU for calculating the measured values, the information recorder for saving measured values, and the display device for indicating the fuel amount consumed during driving.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.601-604
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• 2012

최근 유 무선 통신을 이용하여 원격으로 기기의 상태나 센서 등의 입력장치를 모니터링하거나 출력장치를 제어하기 위한 여러 가지 많은 시도가 있었으며 이에 대한 연구 및 개발도 활발하게 진행되고 있다. 본 논문에서는 다수의 세대를 가지고 있는 아파트의 관리사무소와 세대 사이에 전용 통신망을 개설하여 세대에서 사용하는 전력의 사용량을 입주자가 부재시에도 원격으로 전력 사용량을 검침하고 컴퓨터로 에너지 사용량을 정확하게 검침함으로서 검침요원의 수동검침으로 인한 오류를 없애 입주자와 관리자간의 신뢰성을 확보할 수 있는 모니터링 시스템을 개발한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2283-2286
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• 2003

This paper presents conservation of electrical energy in building with harmonics analysis and compensation which occur in electrical system. We use load controlling and management system in order to adjust load factor of system.The maximum demand limiting and controlling are used ,then the system can acquire the prediction and compare it to the maximum demand set point.The electrical signal analysis based on FFT technique. The harmonics are compensated by using harmonic filters.This system consists computer which works as controller, processor , analysis and database unit together with digital power meter in form of multidrop network through serial communication via RS-485.The load control system uses PLC to control load via serial communication RS-485. The A/D converter is used for sampling the electrical signals via parallel port of computer.The harmonic filters are controlled by a computer.The data of measurement such as voltage, current, power, power factor, total harmonic distortion, energy, etc., can be saved as database and analysis. The load factor is adjusted by limiting and controlling maximum demand. The load factor adjustment can reduce the cost of electric consumption and energy generation together with harmonics compensation in order to increase high efficiency of electrical system.

• 한국통신학회논문지
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• 제40권12호
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• pp.2503-2510
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• 2015

본 논문에서는 전력 정보를 측정하기 위한 단상 에너지 측정용 IC의 구현 방법을 제안한다. 제안된 전력 측정용 IC는 2개의 PGA(Programmable Gain Amplifier), 2개의 ${\sum}{\Delta}$ modulator, reference 회로, LDO(Low-dropout) regulator, 온도 센서, 필터부, 계산 엔진, 보정 제어부, 레지스터, 외부 인터페이스로 구성된다. $0.18-{\mu}m$ CMOS 공정으로 제작되었고, 32-pin QFN package로 제작되었다. 구현된 IC는 3.3V 전원을 공급받아 동작하며, 동작 클럭 주파수는 4,096 kHz이고, IC 동작시 소비 전력은 10 mW이다.

• 대한치과기공학회지
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• 제35권3호
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• pp.201-207
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• 2013

Purpose: In this study, the loosening torque test was conducted with three implant products that are produced, approved and sold in Korea, which are manufactured in different fixture and abutment tightening methods (internal submerged type, internal morse taper type, and external type) to examine the loosening torque of the screw according to the method of tightening the implant fixture and abutment. Methods: In the loosening torque test, the three types of fixtures and abutments with different tightening methods were tightened by rotating them clockwise with a $30N{\cdot}cm$ force using a driver equipped with an electric torque meter. The results of the test are as follows. Results: The loosening torque values of the internal submerged type, internal morse taper type and external type implants were $24.10{\pm}0.742N{\cdot}cm$, $29.10{\pm}1.710N{\cdot}cm$, and $26.60{\times}1.636N{\cdot}cm$, respectively. Conclusion: The screw loosening torque values of the three fixture and abutment tightening methods were analyzed via Kruskal Wallis test layout, and they were significantly different (p<0.05).

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.1119-1120
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• 2017

본 논문은 전기 누진요금제의 문제점과 이를 해결하기 위한 해결책으로 드론을 이용한 전력량계 자동 검침 시스템을 제안한다. 전력 사용량을 줄이기 위해 도입된 누진요금제가 도입 의도와는 달리 검침인력부족으로 인한 가구별 검침 시간 차이로 인해 같은 전기량을 사용하더라도 더 많은 요금을 부과 받게 되는 가정이 발생함에 따라 형평성에 대한 논란을 낳았다. 따라서 인건비 상승을 피하고 이를 해결하기 위한 방안으로 검침원을 대신해 드론이 공중에서 비행하며 여러 가구를 대상으로 사용량 정보를 수집하는 시스템을 제안한다. 이를 통해 검침 시간의 차이를 줄여 형평성을 보장하고 측정 데이터를 수기로 기록할 필요 없이 즉각적으로 데이터화 할 수 있다. 또한 사람이 닿기 힘든 오지에서 활용한다면 인력을 사용하는 것 보다 효과적이고 더 나은 편의성을 제공해 줄 수 있다.

• 수산해양기술연구
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• 제32권1호
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• pp.67-77
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• 1996

The heat transfer performance of R - 11 vapor condensing on integral fin tubes has been studied using fin tubes having the fin density from 748 to 1654 fins per meter. Electric heater supplied heat energy to the boiler to generate R - 11 vapor over the range of 25-60W. Condensation rates of each tubes were tested under the condition of cooling water flow rate from 400l/h to 2500l/h. For the seven fin tubes tested, the best performance has been obtained with a tube having a fin density of 1417fpm and a fin height of 1.3mm. This tube has yielded a maximum value of the heat transfer coefficient of 16500W/$m_2$K, at a vapor to wall temperature difference of 3K. Experimental results of integral fin tubes have been compared with available predictive models such as Beatty - Katz's analysis, Webb's analysis, Sukhatme's analysis and Rudy's empirical relation. The experimental results were shown to be in good agreement with that of the Sukhatme's analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.455-458
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• 2002

In this paper, the physical and volume resistivity properties of cross-linked polyethylene (XLPE) for ultra-high voltage investigated due to temperature dependence, and the measurement of volume resistivity used to highmegohm meter is measured from 1 to 30 minutes when the each applied voltage, for example, DC 100[V], 250[V], 500[V] and 1000[V] is applied, according to the step voltage application method. From FT-IR spectrum as an analysis of physical properties, a strong absorption in wavenumbers 700 to 730[$cm^{-1}$ /], 1456[$cm^{-1}$ /] and 2700 to 3000 [$cm^{-1}$ /] observed by the methyl groups(CH$_2$). From the analysis of DSC, the crystalline melting points of the specimen observed in the temperature 60[$^{\circ}C$] and 106.58[$^{\circ}C$].

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.180-183
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• 2000

The Battery Energy Storage System(BESS) has lots of advantages such as load levelling, quick response emergency power(spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. The economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS nationally. In this paper, we proposed the economic assessment model of customer owned Battery Energy Storage System(BESS) which is complemented and improved the existing model. The proposed model is applied to the typical customer type(light-industrial commercial, and residential) which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic assessment performed for each customer type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, overall benefits, ROI, and ROR. The results of this paper are useful to the customer investment decision making and the national energy policy & strategy.