Wyniki 1-3 spośród 3 dla zapytania: authorDesc:"Mohd Wazir Bin MUSTAFA"

Ground Fault Protection Methods of a Generator Stator

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The type of generator grounding method and the system configuration determine the choice of ground fault protection. Ground fault generator stator can cause serious damage to the generator. Therefore, the total area of the generator stator windings must be protected against hazardous condition. Because the conventional methods are unable to separate ground faults close to the neutral point of view, there should be a method to protect entire stator winding. The paper discusses ways to discern ground faults for the generator stator. Some suggestions are proposed that can help in ensuring the generator stator ground fault more accurate. Streszczenie. Stojan wirnika generatora powinien być szczególnie chroniony przed zagrożeniami. Konwencjonalne metody nie są w stanie oddzielić błąd uziemienia w pobliżu punktu neutralnego. W artykule opisano metody zabezpieczeń stojana generatora przed błędami uziemienia (Zabezpieczenia stojana generatora przed błędami uziemienia) Keywords: Generator Stator, Ground Fault Protection Słowa kluczowe: stojan generator, uziemienie, zabezpieczenia Introduction Synchronous generators are essential part of the power system. Disruption of the generator stator windings, especially in operation, can stop the generator. The process must be greatly detrimental to the generator companies, as this could result to the termination of plant operations, which means less revenue, as well as very high cost of repairing the damaged generator. Due to the importance of the generator stator winding, a protection system that protects the stator from the ground fault (GF) is a necessity. The general kinds of the generator fault are the GF [1]. For a single line to ground fault near the neutral, the generated voltage available to drive current to the fault is small. The result is a fault with a low current and also a low neutral voltage displacement. At the most extreme, if the GF happens at a neutral point of its own, where no f[...]

An accurate fault detection and location on transmission line using wavelet based on Clarke's transformation DOI:10.12915/pe.2014.11.42

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This paper presents accurate fault detection and location using wavelet based on Clarke's transformation. This study was done using Clarke's transformation method to convert current phase (three phase) signal into a two-phase current alpha and beta (current mode). The proposed method introduced the mode current to transform the signal using discrete wavelet transform (DWT) and was utilized to obtain the wavelet transform coefficients. Analysis was also conducted for other mother wavelets. The most accurate parent was wavelet Db8, with the fastest time of detection and the smallest error, whereas the largest error was found in Coil4 parent wavelet. The result for proposed method was compared with Db4, Sym4, Coil4 and Db8 and found to be very accurate Streszczenie. W artykule opisano dokładną metodę wykrywania awarii w sieciach przesyłowych bazująca na falkowej transformacie Clarka. Sygnał trójfazowy jest przekształcany do postaci dwufazowej Za najbardziej się do tego celu nadająca uznano falkę Db8 z najszybszym czasem wykrywania i najlepszą dokładnością. Wyniki porównano z innymi typami falek. Dokładna metoda lokalizacji awarii w sieciach przesyłowych bazująca na wykorzystaniu transformaty falkowej Clarka Keywords: Wavelet Transformation; Fault location; Fault detection; Clarke's Transformation. Słowa kluczowe: wykrywanie i lokalizacja awarii, transformata falkowa, transformata Clarka. doi:10.12915/pe.2014.11.42 Introduction Fault detection and determination of the location of short circuit transmission lines have become a growing concern. There are two commonly used methods to determine the location of the fault in accordance with standard IEEE Std C37.114. 2004 [1]. The first method is based on a frequency component, and the second is based on signal interference at high frequencies where the wave theory is ignored and a shorter sampling window is used [2]. The determination of wave theory for intrusion detection wa[...]

Single line to ground-fault detection for unit generatortransformer based on wavelet transform and neutral networks DOI:10.15199/48.2018.12.07

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Small current Ground-Fault (GF) detection has been a major concern in protective relaying for a long time. Relaying engineers and researchers often face the challenge of developing the most suitable technique that can detect faults with reasonable reliability to secure the run of a power system [1]. In general, a step up transformer at an electric power station can be categorized either as a unit generator-transformer configuration, a unit generatortransformer configuration with generator breaker, a crosscompound generator or a generator involving a unit transformer [2,3]. A GF on the transmission line or busbar can affect the system configuration of the generator. Several methods have been reported for generator GF protection [4]. These methods have been developed based on conventional method, third harmonic method, sub-harmonic injection method and numerical protection method. Fault detection and classification algorithms based on Wavelet Transform (WT) and Artificial Neural Network (ANN) was proposed in [5, 6]. Various feature extraction methods based on WT have been used for the detection and classification of fault. Reference [6] descibe fault location techniques in power system based on traveling wave using wavelet analysis and GPS timing. Fault classification algorithm based on energy and wavelet entropy in transmission have been proposed in [7, 8]. Reference [9-11] describe the feature extraction method based on fast WT, a fault index and wavelet power for use to detect the stator faults in the synchronous generator. Extraction of a statistical parameter as fault detection has been used for fault detection in previous studies, but only used standard deviation, kurtosis and skewness [12]. Meanwhile, the statistical feature parameters include kurtosis, skewness, crest factor, clearance factor, shape factor, impulse factor, variance, square root amplitude value and absolute mean amplitude value to fault diagnosis in [...]

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