• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.767-769
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• 2004

The linear motor is widely used to generate linear motion. In this paper, the iron loss analysis of the linear motor is performed by using ANSYS, a commercial FEA tool and iron loss curves obtained by an Epsteiin test apparatus. For the validation of the iron loss analysis result, the experiment measuring the iron loss of the linear motor is peformed and this result is compared with iron loss analysis result.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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• pp.172-174
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• 2002

Concerns for wind energy as alternative energy have been highly increased, because of the problems such as the global warming effect, environmental pollution, the exhausting fossil fuel, and so on. Recently, the number of variable-speed wind turbines adopted pitch control apparatus has increased. In this paper, the mechanism between the wind energy and power generating system has been presented to specify the relationship of the energy transfer using the Pitch Control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3162-3164
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• 1999

In this paper, a temperature compensating system(TCS) for LPG dispenser has been developed. A TCS includes a processor(80C196) with an AID converter. I/O port(82C55) and 6-digit vacuum fluorescent display. Based on encoding signals from the gas flow meter, different calibration values from each apparatus and temperature compensating values from the temperature sensor, the TCS controls the LPG dispensing quantity with switching on or off the solenoid valves. The temperature compensation is performed with analog-to-digital conversion of the temperature sensor. The resolution of temperature compensation is nearly $0.5^{\circ}C$ using 10-bit ADC. The field test of the TCS shows the exact temperature compensation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1879-1881
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• 2003

In this paper, acoustic signals in $SF_6$ gas were analyzed using wavelet transform. For this, the PD sources in the $SF_6$ gas were divided into corona discharge surface discharge void discharge and crossing particle and acoustic signals were used to detect the PD sources. The measured signals were time-frequency distribution by wavelet transform and the features were extracted from the PD sources. As a result the characteristics of the PD sources were different. And this results is going to be used for basis diagnosis of $SF_6$ gas insulated apparatus.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.888-890
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• 2003

In the distribution networks, it is required to develop compact and smart current and voltage sensors for compact and digital switchgears. The sensor developed newly adopt the priciple of rogowski coil for current sensing and resistive voltage divider for voltage sensing. The sensing characteristics and reliabilities were improved compared to conventional ones. In the near future, these voltage and current sensing apparatus will be widely used with electronic protection units for the distribution switchgear.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기설비전문위원
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• pp.97-100
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• 2004

HFPD(High Frequency Partial Discharge) measurement has been widely performed to diagnosis of cable system in the world although Korea just begin. The efficiency of measurement has been reported and proved by many researchers who are engaged in the diagnosis of high power apparatus. LG Cable has investigated the technology of diagnosis for cable system by means of PD measurement for 10 years. In this paper, PD measurement with portable device was performed to evaluate the quality of the 154kV transmission line and the 22.9kV XLPE cable line. Test results are shown that the HFPD detection technology is very attractive for the diagnosis of power cable system by high detection sensitivity at on-site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.265-267
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• 2000

The RMU is a power apparatus which is used in loop network distribution system. This paper considers the development of the hybrid interrupter in RMU which adopts both rotating arc and thermal expansion technology. Because of the operating principle of this device, it has some merit, compared with other interrupter. In this research, the geometric construction of the interrupting techniques are given and experimental results of hybrid interrupter which is developed by new technology is introduced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.15-18
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• 1996

In the case of need for reciprocating motion, the study for application of Linear Oscillating Actuator(LOA) is being accomplished. LOA is the simpler and more efficient than other linear apparatus using the rotary motor because LOA produce the thrust force without any converter such as cam, clutch, rack, pinion and belt, etc. We designed the flat moving core type LOA and manufactured for trial. This paper shows the structure and dynamic characteristics of LOA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.88-90
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• 2009

Extremely-Low-Frequency(ELF) magnetic fields are generated around power cables and bus bars in power systems. Such the stray fields may cause disturbances to nearby electronic apparatus and affect even human health. In order to seeking out a proper way to reducing the fields, the first thing to do is to accurately predict field distribution around analysis models of interest. Then, optimization techniques should be applied for finding a more improved design than the initial one. To achieve this goal, commercial electromagnetic software, MagNet, is combined with evolution strategy algorithm. For verification of the proposed method, three-phase power line cables and busbar systems have been tested.

• 한국안전학회지
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• 제26권5호
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• pp.33-40
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• 2011

In the hazardous areas where explosive liquids, vapors and gases exist, electrical apparatus/equipment should have explosion-proof construction. The consuming of liquefied natural gas(LNG) has markedly increased in the industrial field, especially in aspect of some thermoprocessing equipment, boiler, dryer, furnace, annealer, kiln, regenerative thermal oxidizer(RTO) and so on. Because it has many merits, clean fuel, safety, no transportation/storage facility and so on. It is strongly recommend that the classification of hazards has to be decided to prevent and protect explosion which may occur in thermoprocessing equipment. In this paper, the operated thermoprocessing equipments in industrial area investigated and explosion risk assessment about LNG leakage from its facilities was performed through numerical calculation and computer simulation. Finally, we suggest the systemic/technical approach for safety assessments of thermoprocessing equipments consumed LNG fuel which are specially subjected to classification of hazardous area.