• JSTS:Journal of Semiconductor Technology and Science
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• 제17권1호
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• pp.65-78
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• 2017

Single Event Transient has a critical impact on highly integrated logic circuits which are currently common in various commercial and consumer electronic devices. Reliability against the soft and intermittent faults will become a key metric to evaluate such complex system on chip designs. Our previous work analyzing soft errors was focused on parallelizing and optimizing error propagation procedures for individual transient faults on logic and sequential cells. In this paper, we present a new propagation technique where a fault binary decision diagram (BDD) continues to merge every new fault generated from the subsequent logic gate traversal. BDD-based transient fault analysis has been known to provide the most accurate results that consider both electrical and logical properties for the given design. However, it suffers from a limitation in storing and handling BDDs that can be increased in size and operations by the exponential order. On the other hand, the proposed method requires only a visit to each logic gate traversal and unnecessary BDDs can be removed or reduced. This results in an approximately 20-200 fold speed increase while the existing parallelized procedure is only 3-4 times faster than the baseline algorithm.

• Journal of Electrical Engineering and information Science
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• 제1권2호
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• pp.52-57
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• 1996

Detection of arcing high impedance faults has been a perplexing in the power distribution protection. Transient analysis of distribution disturbances for fault discrimination from other normal events is important for a secure protection of the power system. A simple parameter of wave form distortion quantification is used to analyze the behaviors of arcing faults and normal distribution disturbances. Theoretical perspectives of the transients were studied and actual disturbances were examined. From this investigation, a discrimination guideline based on the revised crest factor is developed. The discrimination method has a high potential to enhance the reliability and security for the distribution system protection.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1781-1789
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• 2006

Fourier methods are not generally an appropriate approach in the investigation of faults signals with transient components. This work presents the application of a new signal processing technique, the Hilbert-Huang transform and its marginal spectrum, in analysis of vibration signals and faults diagnosis of gear. The Empirical mode decomposition (EMD), Hilbert-Huang transform (HHT) and marginal spectrum are introduced. Firstly, the vibration signals are separated into several intrinsic mode functions (IMFs) using EMD. Then the marginal spectrum of each IMF can be obtained. According to the marginal spectrum, the wear fault of the gear can be detected and faults patterns can be identified. The results show that the proposed method may provide not only an increase in the spectral resolution but also reliability for the faults diagnosis of the gear.

• 전자공학회논문지SC
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• 제48권3호
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• pp.40-47
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• 2011

본 논문에서는 상태 피드백 제어를 이용한 비동기 순차 머신의 고장 탐지 및 극복 과정을 다룬다. 논문에서 고려하는 비동기 머신은 간헐 고장의 영향을 받는다. 간헐 고장이 발생하면 머신은 원하지 않는 상태 천이를 하며, 일정 시간 동안 외부 입력의 변화에 반응하지 못하고 고장 상태를 유지한다. 본 논문에서는 비동기 머신에서 발생하는 간헐 고장을 탐지할 수 있는 조건을 규명하고 간헐 고장을 극복하는 견실한 상태 피드백 제어기의 존재조건과 설계 알고리듬을 제안한다. 과도 고장에 대한 기존의 내고장성 제어 기법과 이번 연구에서 제안하는 간헐 고장에 대한 제어기 동작과의 차이점도 설명한다. 또한 사례 연구를 통해서 제안된 제어기의 설계 과정을 예시한다.

• 전기학회논문지
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• 제58권7호
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• pp.1294-1303
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• 2009

This paper presents a new numerical algorithm for fault discrimination and fault location estimation when occur to arcing ground and arcing line to line on transmission lines. The object of this paper is developed from new numerical algorithm to calculate the fault distance and simultaneously to make a distinction between transient and permanent faults. so the first of object for propose algorithm would be distinguish the permanent from the transient faults. This arcing fault discrimination algorithm is used if calculated value of arc voltage amplitude is greater than product of arc voltage gradient and the length of the arc path, which is equal or greater than the flashover length of a suspension insulator string[1-3]. Also, each algorithm is separated from short distance and long distance. This is difference to with/without capacitance between short to long distance. To test the validity of the proposed algorithms, the results of algorithm testing through various computer simulations are given. The test was simulated in EMTP/ATP simulator under a number of scenarios and calculate of algorithm was used to MATLAB.

• 대한전기학회논문지:전력기술부문A
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• 제51권4호
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• pp.163-168
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• 2002

This paper present a new verb efficient numerical algorithm for arcing faults detection and fault distance estimation in transmission line. It is based on the fundamental differential equations describing the transients on a transmission line before, during and alter the fault occurrence, and on the application of the "Least Error Squares Technique"for the unknown model parameter estimation. If the arc voltage estimated is a near zero, the fault is without arc, in other words the fault is permanent fault. If the arc voltage estimated has any high value, the faust is identified as an fault, or the transient fault. In permanent faults case, fault distance estimation is necessary. This paper uses the model of the arcing fault in transmission line using ZnO arrestor and resistance to be implemented within EMTP. One purpose of this study is to build a structure for modeling of arcing fault detection and fault distance estimation algorithm using Matlab programming. In this paper, This algorithm has been designed in Graphic user interface(GUI).

• 제어로봇시스템학회논문지
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• 제17권1호
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• pp.72-77
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• 2011

The checkpointing scheme is a well-known technique to cope with transient faults in digital systems. This paper proposes an adaptive checkpointing scheme for the reliability improvement of real-time control systems with concurrent fault detection capability. With concurrent fault detection capability the effect of transient faults are assumed to be detected with no latency. The proposed adaptive checkpointing scheme is based on the reliability analysis of an equidistant checkpointing scheme. Numerical data show the proposed adaptive scheme outperforms the equidistant scheme from a reliability point of view.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.742-749
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• 2011

Power transmission lines are one of the most important components of electric power system. Failures in the operation of power transmission lines can result in serious power system problems. Hence, fault diagnosis (transient or permanent) in power transmission lines is very important to ensure the reliable operation of the power system. A hidden Markov model (HMM), a powerful pattern recognizer, classifies events in a probabilistic manner based on fault signal waveform and characteristics. This paper presents application of HMM to classify faults in overhead power transmission lines. The algorithm uses voltage samples of one-fourth cycle from the inception of the fault. The simulation performed in EMTPWorks and MATLAB environments validates the fast response of the classifier, which provides fast and accurate protection scheme for power transmission lines.

• 전기학회논문지P
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• 제62권3호
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• pp.151-158
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• 2013

Large generator of power plant is very important. In order to protect large generator from faults, digital protective relay or IED is required. However, all protective relays for generators of the domestic power plant are operated by foreign products. And now, for technological independence from foreign and improvement of import substitution effect, IEDs using domestic technology are being developed. To evaluate performance of developing next-generation power devices, the study of the dynamic characteristics of the power plant, generator system modeling, fault simulation and analysis, should be considered. Specially, To obtain IEEE Standards COMTRADE format for relay operation test, generator system modeling and fault simulation using PSCAD/EMTDC tools must be preceded. Until now, a complete modeling of generator internal windings and fault simulation techniques dose not exist. In this paper, for evaluation performance of relay elements of developing IED, the generator system modeling and various faults simulation using PSCAD/EMTDC tools were performed. And then, the various transient phenomena through obtained relaying signal of developed modeling were analyzed.

• Journal of Electrical Engineering and Technology
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• 제1권1호
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• pp.35-41
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• 2006

This paper presents a new numerical algorithm for fault location estimation and for faults recognition based on the synchronized phasors. The proposed algorithm is based on the synchronized phasor measured from the synchronized PMUs installed at two-terminals of the transmission lines. In order to discriminate the fault type, the arc voltage wave shape is modeled numerically on the basis of a great number of arc voltage records obtained by transient recorder. From the calculated arc voltage amplitude it can make a decision whether the fault is permanent or transient. The results of the proposed algorithm testing through computer simulation are given.