• 한국화재소방학회논문지
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• 제16권3호
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• pp.8-11
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• 2002

전기배선계통에 있어서 접속점의 접속 접촉불량과 순간단락 시 발생하는 스파크와 열축적은 절연물의 용착과 탄화현상을 발생하여 전기화재의 주요 원인이 되고 있다. 또한 접속점의 접속·접촉불량과 순간단락 시 발생하는 전류는 일종의 써지(Surge)전류가 되어 통신, 가전제품, 컴퓨터 그리고 각종 측정기기의 소손 및 고장을 일으키며, 특히 접속점의 접속·접촉불량과 순간단락은 다양한 현상을 나타내어 안전점검시 발견이 매우 어려운 실정이다. 따라서, 본 논문에서는 누전차단기(Earth Leakage Breaker)의 보조 제어장치, 즉 전기화재예방 제어장치(Electrical Fire Prevention Control Device)를 개발하여, 상기 접속점의 접속·접촉불량과 순간 단락 시 누전차단기의 동작신뢰성을 제고시켜, 스파크와 접속점의 과열에 의한 전기화재를 예방하고자 한다.

• 한국전기전자재료학회논문지
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• 제29권5호
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• pp.307-311
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• 2016

Although there are existing Residual Current Protective Device (RCD) including detect electric leakage and elements such as short circuit and surge, the occurrence of incidents caused by electric faults, including fire, are still constant. The purpose of this study is to analyze the causes of accidents through the electric field distribution in the interpretation of the fault contact breaker. Simulation results by the arc fault has shown the convergence of temperature and electric field to the defect. Through their simulation results, the main cause of erosion phenomena in circuit breaker bar is the electric arc by concentration of electric field not due to dissolve by temperature.

• 조명전기설비학회논문지
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• 제27권5호
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• pp.81-88
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• 2013

A low voltage circuit breaker protects electrical equipments from over current and short faults of system by cutting the power supply. The breaker use a thermal magnetic type trip device from the past. In recent years, electronic type relays are applied due to useful functions and services. The purpose of this development is full digitalizing of relay functions of a low voltage breaker. It includes separation of current sensor from current transformer, digital signal processing, high speed relaying, and voltage measuring for power meter. The suggestions are tested and implemented by making prototype and testing its all relay functions.

• 전기학회논문지
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• 제65권6호
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• pp.1108-1114
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• 2016

The cause of failure in the AT feeding system is divided into grounding, short-circuit of feeding circuit and internal faults of the railway substation. Since the fault current is very high, real-time current is detected and the failure must be immediately removed. In this paper, a new DC offset elimination filter that can remove component to decrease in the form of exponential function using low-pass filter was proposed in order to extract the fundamental wave from distorted fault current. In order to confirm the performance of the proposed filter method, AT feeder system was modelled by simulation tool and simulations were performed under various conditions such as fault location, fault resistance and fault voltage phase angle in case of trolley-rail short-circuit fault. When applying the proposed DC-offset removal method, it can be seen that the phase delay and gain error did not appear.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2102-2103
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• 2008

The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device(RCD) of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms](KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this paper is proposed to a electrical fire disaster prevention device(EFDPD) for a RCD trip or a self circuit-breaking function on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

• 전기학회논문지
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• 제56권11호
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• pp.1925-1929
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• 2007

This paper is studied on a novel Electric Safety Protection Device (ESPD) of high speed for incapable operation of Earth Leakage Circuit Breaker (ELB) and Molded_case Circuit Breaker (MCCB) using the low voltage distribution line. The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is ELB and MCCB, of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a novel ESPD of high speed to trip of distribution line on electric arc or spark due to electrical fire. Some experimental results of the proposed ESPD are confirmed to the validity of the analytical results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.154-156
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• 1993

In this paper, fault analysis using simulation method and fault diagnosis scheme are presented for induction motor drive system. Major faults such as inverter 'a' phase open fault, inverter 'a'-'b' phase short circuit fault and inverter 'a' phase ground fault are analyzed and simulated. On-line and off-line fault diagnosis systems are proposed.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2005년도 공동추계학술논문발표회 논문집
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• pp.213-219
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• 2005

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2278-2288
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• 2017

Multilevel converter topologies are widely used in many applications. The cascaded H-bridge multilevel inverter (CHBMI), which is one of many multilevel converter topologies, has been introduced as a useful topology in high and medium power. However, it has a drawback to require a lot of switches. Therefore, the reliability of CHBMI is important factor for analyzing the performance. This paper presents a simple switch fault diagnosis method for single-phase CHBMI. There are two types of switch faults: open-fault and short-fault. In the open-fault, the body diode of faulty switch provides a freewheeling current path. However, when the short-fault occurs, the distortion of output current is different from that of the open-fault because it has an unavailable freewheeling current flow path due to a disconnection of fuse. The fault diagnosis method is based on the zero current time analysis according to zero-voltage switching states. Using the proposed method, it is possible to detect the location of faulty switch accurately. The PSIM simulation and experimental results show the effectiveness of proposed switch fault diagnosis method.

• Journal of Power Electronics
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• 제16권3호
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• pp.1097-1109
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• 2016

Fault detection and isolation are related to system monitoring, identifying when a fault has occurred, and determining the type of fault and its location. Fault detection is utilized to determine whether a problem has occurred within a certain channel or area of operation. Fault detection and diagnosis have become increasingly important for many technical processes in the development of safe and efficient advanced systems for supervision. This paper presents an integrated technique for fault diagnosis and classification for open- and short-circuit faults in three-phase inverter circuits. Discrete wavelet transform and principal component analysis are utilized to detect the discontinuity in currents caused by a fault. The features of fault diagnosis are then extracted. A fault dictionary is used to acquire details about transistor faults and the corresponding fault identification. Fault classification is performed with a fuzzy logic system and relevance vector machine (RVM). The proposed model is incorporated with a set of optimization techniques, namely, evolutionary particle swarm optimization (EPSO) and cuckoo search optimization (CSO), to improve fault detection. The combination of optimization techniques with classification techniques is analyzed. Experimental results confirm that the combination of CSO with RVM yields better results than the combinations of CSO with fuzzy logic system, EPSO with RVM, and EPSO with fuzzy logic system.