Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Amr ABOU-GHAZALA"

A Novel Protective Scheme for Double Circuit Transmission Line Based on Modular Neural Network of Combined Structure

Czytaj za darmo! »

A novel application of neural network approach to protection of double circuit transmission line is demonstrated in this paper, to enhance the solution of problems associated with distance protection of parallel transmission lines. Concept of modularity is applied to the neural network structure to reduce its complexity and processing time. Results of performance evaluation studies show that the proposed modular neural networkbased relay can improve the performance of conventional protection algorithms. Streszczenie. W artykule opisano wykorzystanie sieci neuronowych do zabezpieczenia linii przesyłowej. Dla zmniejszenia złożoności układu przy dużych odległościach zaproponowano modularną strukturę sieci neuronowej. (Nowa metoda zabezpieczenia dwuobwodowej sieci przesyłowej bazująca na modularnej sieci neuronowej) Keywords: Double Circuit Transmission Lines, Modular Neural Network, Distance Protection Relays. Słowa kluczowe: linia przesyłowa, zabezpieczenie, sieć neuronowa Introduction The basic operation of distance relays, the fundamental component of almost all transmission line protection, depends on the impedance measured at the relay location. For the conventional digital distance relays, the impedance seen at the relay location is calculated from the fundamental component of the voltage and current signals. The accuracy of the impedance estimation depends on how accurately the fundamental components of voltage and current signals are extracted. This requires using appropriate filtering algorithms. In order to minimize the error caused by non-fundamental components, the size of sampling window should be increased. Thus, the accuracy of an impedance estimate reduces with the increase in the speed at which that estimate is obtained [1]. In addition, when a fault happens on a transmission line, the power system goes through a transient period. It might not be easy to determine current/voltage signal magnitudes immediately and ac[...]

Custom power devices for voltage sags mitigation: a techno-economic analysis

Czytaj za darmo! »

The increased concern about the financial losses due to voltage sags and interruptions plus the advancements in power electronics technology have led to the innovation of very fast acting intervening equipment that can mitigate such disturbances. However, the high cost of these custom power devices can offset their technical benefits. In this paper, a procedure is proposed to find a compromised solution that makes technical and financial sense. A case study of an oil refinery in Alexandria, Egypt is considered to illustrate the proposed procedure. Abstract. Wzrastające znaczenie ekonomiczne strat powodowanych przez zapady napięcia i przerwy prowadzą do opracowania urządzeń pozwalających na szybką interwencję. Niestety takie systemy są dość kosztowne. W artykule zaproponowano rozwiązanie kompromisowe aspektu technicznego i ekonomicznego. Analizę wykonano na przykładzie rafinerii w Alaksandrii w Egipcie. (Specjalistyczne układy zasilania ze złagodzeniem zaników napięcia - analiza techno-ekonomiczna) Keywords: Voltage Sags, Short Interruptions, Power Quality, Custom Power Devices, Techno-economic Analysis. Słowa kluczowe: jakość energii, zapady napięcia. Introduction Voltage sags and short interruptions are brief voltage reduction events, followed by restoration of the normal supply conditions. Voltage sags and short interruptions are frequent causes of tripping of electrical equipment in industrial installations, leading to costly shutdowns [1]. Custom power devices are power electronic based devices used to protect the entire facility from such voltage disturbances. Custom power devices have to work within parts of a cycle, such that the load bus will not be affected by the supply disturbance [2]. This paper proposes a methodology for the decision makers, to compare the technical merits and limitations of these devices, along with an economical evaluation of their costs against the financial losses of sags and interruptions. Voltage[...]

 Strona 1