• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.1499-1500
• /
• 2015

국내 전력공급을 위한 배전설비는 2014년 12월 기준으로 고압전주 약 404만기와 지상기기 약 9만 6천대 등이 전국 각지에 분포되어 있으며 한국전력공사에서는 안정적 전력공급을 위한 배전선로 최적관리를 위하여 다양한 진단 장비를 활용 설비진단을 시행하고 있다. 이중 열화상진단은 당사에서 가장 널리 활용되는 배전설비 진단방법으로 타 진단장비에 비해 사용상의 편의성을 갖춤으로써 활용빈도는 높아지는 추세이나, 사용자의 진단장비에 대한 이해 부족 및 진단기술 수준부족으로 불량 적출률은 진단자에 따라 많은 차이를 보이고 있다. 또한 사업소별 진단실적 및 이에 따른 고장 발생 현황도 큰 차이를 보이고 있다. 이에 본 논문에서는 다양한 사례를 통하여 효과적인 열화상 진단방법을 제시하고 최적의 효과를 위한 진단횟수를 제시하고자 한다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집A
• /
• pp.914-919
• /
• 2000

In most case high temperature components in fossil power plant are damaged by fatigue, creep and degradation. Design of power plant components is based on ideal loading such as temperature, pressure and so on. But in many cases unexpected loadings are applied at components. A key ingredient in plant life extension is the preventive diagnosis technology and remaining-life-assessment technology. This paper describes diagnosis technology and life-assessment technology for power plant boiler. It helps in setting up proper inspection schedules, maintenance procedures, and operating procedure.

• Journal of Power Electronics
• /
• 제16권2호
• /
• pp.695-703
• /
• 2016

A fuel cell power conditioning system for online diagnosis and load leveling under the condition of varying load is developed in this study. The proposed system comprises a unidirectional boost converter and a bidirectional buck-boost converter with a battery. The system operates in two different modes. In normal mode, the bidirectional converter is utilized for load leveling; in diagnostic mode, it is utilized to control load voltage while the boost converter generates perturbation current to implement the online diagnosis function through in-situ electrochemical impedance spectroscopy (EIS). The proposed method can perform EIS for a fuel cell under varying-load conditions with no influence on the load. The validity and feasibility of the proposed system are verified by experiments, and the design procedure of the proposed system is detailed.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
• /
• pp.148-151
• /
• 2002

In order to prevent the failures of underground distribution power cables we need to measure insulation condition in the field. Until now we used DC high voltage as a power source for the cable diagnosis but it was not proper method to the XLPE insulation cables because DC high voltage can affect sound insulation and can't diagnose exactly insulation degradation. For these reasons we imported isothermal relaxation current measurement system called by KDA-1 from germany but it's reliability did not proved in our URD cables. DC voltage decay measurement system was developed by domestic company but they don't have field experience. In this paper we tried to prove reliability of these two systems in the field. Through the field diagnosis and Ac breakdown test the two systems showed similar results.

• Nuclear Medicine and Molecular Imaging
• /
• 제40권4호
• /
• pp.193-199
• /
• 2006

Infectious and inflammatory bone diseases include a wide range of disease process, depending on the patient's age, location of infection, various causative organisms, duration from symtom onset, accompanied fracture or prior surgery, prosthesis insertion, and underlying systemic disease such as diabetes, etc. Bone infection may induce massive destruction of bones and joints, results in functional reduction and disability. The key to successful management is early diagnosis and proper treatment. Various radionuclide imaging methods including three phase bone scan, Ga-67 scan, WBC scan, and combined imaging techniques such as bone/Ga-67 scan, WBC/bone marrow scan add complementary role to the radiologic imaging modalities including plain radiography, CT and MRI. F-18 FDG PET imaging also has recently been introduced in diagnosis of infected prosthesis and chronic active osteomyelitis. Selection of proper nuclear medicine imaging method will improve the diagnostic accuracy of infections and inflammatory bone diseases, based on understading of pathogenesis and radiologic imaging findings.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2017년도 춘계학술대회
• /
• pp.355-357
• /
• 2017

최근 자동화 기술의 발전으로 산업체에는 대규모 자동화 시스템으로 변화되고 있다. 그에 따른 시스템 감시와 파라미터 측정에 사용되는 센서 또한 자동화 시스템에서 중요한 요소로 차지하고 있다. 따라서, 자동화 시스템에서 센서의 고장으로 인한 시스템 오작동으로 고장이 발생한다면 경제적 피해 및 인명피해를 초래할 수 있다. 본 논문에서는 센서의 직접적인 고장진단을 위해 Kung's Algorithm을 이용하여 센서 출력값 모델링과 결정이론을 통한 고장진단방법에 대해 제시한다.

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

• 전기학회논문지
• /
• 제62권1호
• /
• pp.105-108
• /
• 2013

To resolve global environmental problems, many automobile companies are making a great deal of effort to develop so-called green-cars. One of the solutions is an electric vehicle equipped with the PEMFC (Proton Exchange Membrane Fuel Cell) stack. However, the cost of the stack, at the moment, is still too high. This obstacle must be resolved for commercialized fuel cell cars. One of the reasons for high cost is a relatively large amount of Pt (platinum) in the membrane. In this paper, a method for reducing the Pt-loading is introduced. Furthermore, the durability of the stack will be important for a company to stay competitive in world markets (in the future). For this, the diagnosis of the stack must be conducted on-line. Some diagnosis methods as key technology are also introduced in this paper.

• 조명전기설비학회논문지
• /
• 제26권10호
• /
• pp.44-51
• /
• 2012

The purpose of this study is development of the diagnosis system to preventative maintenance in the on-board measuring systems for in-cab electric inspection systems of high speed railway. The on-board measuring systems can inspect precisely whether ground signal system operate stably. In this paper, we recognize characteristics of the track circuits and confirm whether the wave of current matches the on-board measuring data through the electric modeling method for high speed railway. it is necessary to develop GUI visual programs that can simulate abnormalities of the on-board measuring data in many ways, and the visual program is designed to diagnosis in the case of track circuit equipment's function decreased in advance.

• 센서학회지
• /
• 제22권4호
• /
• pp.276-280
• /
• 2013

The purpose of this paper is to diagnose osmidrosis visually and quantify the extent of osmidrosis. To achieve this, we designed the diagnosis method of osmidrosis using electronic nose system. The developed electronic nose system use principal component analysis for visualization of osmidrosis and fuzzy c-means algorithm for quantification. To confirm the efficiency of electronic nose system for osmidrosis diagnosis, we obtained samples from 34 volunteers and compared our experiment results with the doctor's diagnosis, and we met with successful results.