• 한국안전학회지
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• 제29권3호
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• pp.20-27
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• 2014

Cooling equipment is the frequent occurrence of fire despite the absence of the heating element. National fire statistics in 2013 show that a total of 263 fires occurred in the cooling equipment and the number of electric fan has 145 fire cases. This is accounted for 55.1% of the whole. Electric fan is the electrical appliance that the heat is generated on the winding wire and the iron core. If such characteristic is not controled properly, fire would break out at the electric fan. also there is a gap filled with an insulator between connection terminals of the capacitor in the electric fan. But in case that the gap on the capacitor is covered with some conductive material such as dust, there would be a fire as well caused by electrical heating locally. Although many studies related with those have been conducted, electric fan fire is continuously occurred. In this study, thermal characteristics and current signal in various conditions such as the heat generation of windings including iron cores of the motor and the dielectric breakdown of terminals on the capacitor connected to the motor were detected. In order to measure the maximum temperature, "third level" wind velocity button was pushed and the time selection switch to "continuation" was set. Analyzed data would be available for the fire safety of the electric fan.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.119-121
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• 2003

The magnetic bearing is an important element for high-speed system, such as semiconductor equipment and machine tools. Particularly, The homopolar magnetic bearing has the advantages of lower power losses, more space for heat dissipation and coil winding. This paper deals with analysis and comparison of the homopolar magnetic bearing according to four different PM structures. On the basis of these results, we find one homopolar magnetic bearing superior to the others. finally, this paper derive force characteristic equation for this model and deals with comparison of between analytical and FE results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.584-587
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• 1992

Because linear motor directly drives linear motion, it does not need conversion equipment such as belt and gear. Especially linear pulse motor provide more precise positioning and large force of linear pulse motors. As current manufacture technic of linear pulse motor is much to be desired at home. This motor lay out to make use of computer aided design program, In this paper the experimental motor is 2-phases 4-poles hybrid pulse motor which has teeth per pole Simulation program is divided its function into 4 parts - air gap permeance analysis, permanent magnet & non-linear core operating point determine, winding configuration, leakage flux analysis. It is possible to make motor static and magnetic characteristics for this simulation program. Also, by varying input parameters of the program, experimental motor is to be compared to motor characteristics.

• 조명전기설비학회논문지
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• 제28권10호
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• pp.75-81
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• 2014

When the large-capacity Mold type Transformer was passed through rain, after it was dried and it's parts were changed, Insulation Diagnosis was made to evaluate the condition of it and decide to recharge. Using the evaluation of Insulation Diagnosis, the urgent decision-making for recharge made blackout time minimum. In this study, it was considered that Insulation Diagnosis for the large-capacity Mold type Transformer is applied to decision-making for reuse of high voltage electric power equipment by analysis of the case study.

• 유공압시스템학회논문집
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• 제8권1호
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• pp.26-31
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• 2011

To drive hydraulic valve is used Linear force motor, whose force and direction are controlled by electronic signals. Linear force motor has complicated figure and its force produced by changing of flux density which is produced by permanent magnet and electrical winding. Therefore it is needed an exact calculation of the flux density. In this paper a Linear force motor is designed and analysed by 3d program Flu calculating the flux density in air gap and in yoke, Force by different current. The analysed data will be tested by prototype Linear force motor. The data and analysing method can be used for designing Linear force motor.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권8호
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• pp.361-367
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• 2002

Many failures in high voltage equipment are preceded by partial discharge activity. In this paper deals with the application of the high frequency partial discharge measurement technique in motorette. HFPD measurement is very effective method to detect the PD occurred in motorette which is the called name of test specimen for accelerating test of stator winding[1] In this study, CT type HFPD sensor is used to detect the partial discharges and a measured HFPD pattern is analyzed by fractal mathematics. The neural network algorithm is used to pattern recognition and ageing diagnosis. As a result of this study, the fractal dimensions are increased along to applied voltage and HFPD pattern recognition using neural network shown excellent recognition rate. Also, the ageing diagnosis of motorette has been Possible.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.58-60
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• 1999

This paper presents dynamic performance prediction using Matlab / simulink after parameter estimation of synchronous reluctance motor considering iron loss. Test motor is 3 phase SynRM with the segmental rotor, rating power is 0.175KW. Experiment equipment is consists of testing motor, dynamometer, vector invertor dynamocontroller, and power analyser. The stator iron loss and rotor iron loss are modelled by additional windings on three-phase winding axis. These windings are transformed into d-q axis, and are represented as equivalent eddy current windings. P-Q circle diagram method and single phase standstill method are used to measure motor parameters considering iron loss.

• 전기학회논문지
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• 제60권2호
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• pp.301-308
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• 2011

This paper deals with the coupled electromagnetic-mechanical field analysis for short-circuit electromagnetic force of the dry-type transformer. The short-circuit currents are calculated using external circuit in accordance with short-circuit test equipment. According to short-circuit current, the generated magnetic leakage flux density in dry-type transformer model is calculated by finite element method. The radially-directed electromagnetic forces in windings are calculated using electromagnetic field analysis and then axially-directed electromagnetic forces in windings are calculated using electromagnetic-mechanical field analysis. The calculated axially-directed electromagnetic forces in high voltage winding are compared to those of measured ones and showed good agreement with experimental results.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.219-226
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• 1997

This paper investigates and analyzes the installation and failure status of mold transformer being used in domestic subways and describes the extinguishing process by time through the combustion test of winding part of mold transformer. Condition of installed mold transformers and classes of fire were surveyed and the mold transformer was burned in a horizontal heating furnace. It was confirmed that the mold transformer is self extinguishing and nonflammability. According to this results, the suitable standard of fire protection for the mold transformer was demanded after review of domestic and abroad law. It is expected that the cost of fire protection equipment can be reduced by using the status and combustion test result of mold transformer.

• 대한기계학회논문집B
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• 제34권2호
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• pp.137-143
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• 2010

발전기 고정자 권선 내부의 완전 건조는 누수시험을 위한 필요/충분조건이다. 발전기 운전에 의한 고주기 피로는 미세 균열 발생의 원인이 되고, 미세 균열에서의 물분자는 누설 진단의 신뢰성을 저하시킨다. 이와같은 이유로, 발전기 고정자 권선에 대한 누수시험에서 권선에 누설처가 있음에도 불구하고 누설이 없다는 결론과 같은 오류를 범하고 있다. 발전기 제작사는 누수시험을 고유한 건조 판정 기준을 제시하고 있지만, 실제로는 어떤 판정 기준도 누수시험을 위해 정확하게 건조 판정 기준을 지시하고 있지는 못하고 있는 실정이다. 그 이유는 발전기 고정자 권선의 복잡한 구조와 효과적인 건조 장비의 부재 때문이다. 본 논문에서는 수 냉각 발전기 고정자 권선의 내부 건조 여부를 판정하기 위한 건조 판정 기준을 완벽하게 제안하였으며 실험적으로 증명하였다.