• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.274-275
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• 2011

Fault current problems is considered a serious issue in the power system because large fault currents not only cause many side effects to the equipments of power system but also lead to severe problems, such as blackouts. This paper deals with the structural analysis and 3-phase fault current stability of the future Seoul metropolitan power system. The simulation composition and analysis are performed with the 4th KEPCO power supply planning data using PSS/e. Through the results of the simulations, it can be observed that the future Seoul metropolitan system results in a fault current which exceeds the circuit breaker (CB) rate. This unremovable fault current can cause critical damage to power system. To resolve the problem, the algorithm for the application of Voltage Sourced Converter Back-to-Back High Voltage Direct Current (VSC BTB HVDC) is being proposed. where the most suitable location for solving fault current problem in Seoul metropolitan area is being implemented.

• 한국안전학회지
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• 제20권3호
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• pp.19-26
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• 2005

There are three reasoning method in fault diagnosis process. The shallow reasoning is based on the experiential knowledge and deep reasoning is based on physical model. Hybrid reasoning is mixing two type reasoning. This study describes about fault train embodiment of screw type air compressor that is used widely in industrial facilities by using various experimental method and shallow reasoning. We investigate macroscopic failure cause of air compressor through naked eye observation and then microscopic failure cause by various experimental method. We composed fault train with fault knowledge based on empirical data and scientific data that is acquired through several experiments. It is possible to analysis system reliability and failure rate with these fault train.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2005년도 춘계학술대회
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• pp.279-290
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• 2005

The purpose of this study is to attempt a Analysis of a pointed-end Equipment Arm Safety-Accident for Fault Tree Analysis. Three major techniques were used first problem is Z-Model by which accident Analysis & prevention of a pointed-end Industry can be made, Fault Tree Analysis(FTA) bywhich quantification of a pointed-end Equipment accident Analysis can be made it 5 years in past and the third, manual-written by which minimal cut set to accident can be Identified. A example has been made of issue point a pointed-end Equipment that the Arm in loader happen to Injuries. According to the Analysis lack of safety knowledge, unsafety-behavior seem to be the primal cause of accident. Comparision of the accident cause to actual report demonstratesthat the FTA a efficient tool for Industrial Accident prevention.

• 제어로봇시스템학회논문지
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• 제9권2호
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• pp.159-167
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• 2003

This study suggests the hybrid fault diagnosis method of signed digraph (SDG) and partial least squares (PLS). SDG offers a simple and graphical representation for the causal relationships between process variables. The proposed method is based on SDG to utilize the advantage that the model building needs less information than other methods and can be performed automatically. PLS model is built on local cause-effect relationships of each variable in SDG. In addition to the current values of cause variables, the past values of cause and effect variables are inputted to PLS model to represent the Process armies. The measured value and predicted one by dynamic PLS are compared to diagnose the fault. The diagnosis example of CSTR shows the proposed method improves diagnosis resolution and facilitates diagnosis of masked multiple-fault.

• International journal of advanced smart convergence
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• 제1권1호
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• pp.57-60
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• 2012

In this paper, we have performed a safety analysis on an automotive evaporator inspection system. We performed the bi-directional analysis on the manufacturing line. Software Fault Tree Analysis (SFTA) as backward analysis and Software Failure Modes, Effects, & Criticality Analysis (SFMECA) as forward analysis are performed alternately to detect potential cause-to-effect relations. The analysis results indicate the possibility of searching and summarizing fault patterns for future reusability.

• 한국화재소방학회논문지
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• 제30권4호
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• pp.73-81
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• 2016

정온전선은 평형 도체 사이에 반도전성 폴리머를 연속 압출 방식으로 충전시킨 후 양 도체 사이에 전기를 흐르게 함으로써 고분자에 의한 전열을 이용한 전기 발열체이다. 정온전선은 가격이 저렴하고 시공이 편리하기 때문에 겨울철 수배관의 동파방지용 열선으로 주로 사용되고 있다. 하지만 이러한 유용함에도 불구하고 구조적인 문제로 인하여 두 평형 도체의 절연이 파괴되는 경우에는 화재로 이어질 수도 있는 위험성이 존재하고 있다. 본 논문은 정온전선에 의한 화재현장을 조사하여 원인을 도출하는 방식으로 직접적인 원인을 추론하고자 하였으며, 결함수 분석을 통해 근본적인 문제를 파악해 보고자 하였다. 실제 냉동창고 화재현장을 조사하여 정온전선에 의한 화재원인을 추론한 결과 전선 말단 절연처리 결함에 의한 절연파괴인 것으로 판단되었다. 향후 이 결과는 안전활동 및 유사 화재원인조사 시에도 활용될 수 있을 것이다

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.207-210
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• 2001

Electrical equipment for railway is always experiencing wear and degradation by mechanical, electrical and environmental stress in service and the fault or the accident of high voltage main circuit directly causes operation interruption. Particularly propulsion drive of high speed switching inverter takes the form of specific degradation mechanism such as fast rising transient surge, reflective overvoltage and harmonic stress, and it is known that it threatens the long life and the reliability of electrical equipment. In this paper, statistics of fault and accident on main electrical equipment for railway are presented and also insulation degradation mechanism, which governs end life of electrical device, is analyzed. Finally the method of fault respondence and reliability improvement on the main electrical equipments will be reviewed in order to prevent operation interruption.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.912-914
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• 2000

This paper present recent the KEPCO's substation power transformer status and power transformer fault analysis by the fault part, the cause of fault, the manufacture etc.

• 전기학회논문지P
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• 제58권3호
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• pp.362-368
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• 2009

Electrical fires have been occurred continuously in spite of installing ELB. Therefore the concern with the electrical arc-fault that cause the fire has growing. This paper measured series arc fault currents by the method of arc generator test in UL standard 1699. The used analysis methods in this paper are three different ways using DWT(discrete wavelet transform) those are frequently used for the arc fault current signal analysis. The arc fault detection probability is 100 % by method using noise-energy/shoulder-duration ratio of approximation coefficient. As these results, the variation of noise-energy and shoulder-duration ratio of approximation coefficient are founded important factors for the analysis of arc fault.

• 전기학회논문지
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• 제59권6호
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• pp.1025-1033
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• 2010

This paper proposes a method to improve and analysis error cause of FI(Fault Indicator) information to be used for detecting fault section in distribution automation system. FI error cause is made by consideration fault current magnitude and time. So, a new method to prevent FI error is proposed to include fault current magnitude, time and direction. Therefore, it's considered network environments that grounded and ungrounded network in distribution automation system. The proposed method is proved by Matlap Simulink. By the result in this research, it's possible to quickly restoration, supplying stability and reliability power to customer.