الفهرس 
Chapter 1 IntroductionOnly 14 pages are availabe for public view
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Abstract
in conventional distribution systems, power service interruptions are typically recognized with customer calls. Hence, those conventional systems have incomplete information about outage locations which consequently leads to inefficient managements. In order to pinpoint precisely outage locations, reduce restoration time, and hence improve the system reliability, robust tools for fault diagnosis and efficient fault management schemes must be used. This fault management process is initiated when the fault diagnosis is correctly accomplished. However, its satisfactory performance cannot be guaranteed without precise protective transducers. First, the effective problems of conventional transducers are emphasized to outline the next steps to realize an improved performance of such devices for protection applications. Impacts of current transformer saturation on the coordination of overcurrent relays for parallel distribution networks are evaluated. The saturation of current transformers due to the direct current component leads to distort its secondary current causing inaccurate current measurement. This may result in a miss-coordination or malfunction of the primary protection and its backup protection. This false tripping is particularly serious since it may result in isolating larger healthy areas of the network. Unfortunately, this error is normally not considered during optimal overcurrent coordination. Simulation tests are carried out for validation purposes using the ATP/EMTP. Similarly, the current transformers (CTs) saturation impact on fault location for the practical parallel network configuration is evaluated. This cause inaccurate fault location computation which is normally disregarded during the calculation of the fault distance. A comparative study of the most common algorithms for compensating Current Transformer (CT) saturation is presented using some selected algorithms based on different mathematical cores. A detailed CT simulation platform is utilized using the practical CT modeling in the ATP-EMTP. To avoid these expected problems of miss-coordination or malfunction of primary protection and its associated backup protection due to the CT saturation, an improved compensation algorithm for CT saturation is proposed. Then, these compensated errors can be incorroborated into the fault location process. Owing to the importance of realizing an accurate voltage and current measurements, an efficient current tracking method of power frequency signals using Rogowski coil is proposed. In order to compensate the output signal of the Rogowski coil, a direct and simplified digital compensation technique is proposed to reconstruct the input current. The proposed measuring concept is performed by processing its terminal voltage using the discrete Fourier transform (DFT). Both experimental and simulation verification tests are applied. An experimental system is also proposed for the optical current transducer. The basic principle for this transducer is the faraday rotation of light beam through Terbium Gallium Garnet (TGG) which called a crystal material in the presence of an external magnetic field coaxial with the light. There is no doubt that Successful fault diagnosis systems are essential for implementing practical self-healing procedures in automated distribution systems. Successful fault diagnosis effectively decrease repairing times by precise detecting and locating the deteriorated components in distribution networks. Evaluating the reliability of the overall fault diagnosis system will enable the efficacy of the improved measuring transducer to be assessed in modern distribution systems. This reliability is assessed using Markov model analysis for a selected typical practical distribution system. The reliability analysis is computed using dynamic distribution network measurements for the selected distribution system according to the most common IEEE reliability indices. Reliability improvement is evaluated by incorporating modern self-healing procedures in the automatic restoration for distribution networks. Self-healing impact on the reliability evaluation is investigated revealing the automation role for enhancing the network reliability and service continuity. n conventional distribution systems, power service interruptions are typically recognized with customer calls. Hence, those conventional systems have incomplete information about outage locations which consequently leads to inefficient managements. In order to pinpoint precisely outage locations, reduce restoration time, and hence improve the system reliability, robust tools for fault diagnosis and efficient fault management schemes must be used. This fault management process is initiated< when the fault diagnosis is correctly accomplished. However, its satisfactory performance cannot be guaranteed without precise protective transducers. First, the effective problems of conventional transducers are emphasized to outline the next steps to realize an improved performance of such devices for protection applications. Impacts of current transformer saturation on the coordination of overcurrent relays for parallel distribution networks are evaluated. The saturation of current transformers due to the direct current component leads to distort its secondary current causing inaccurate current measurement. This may result in a miss-coordination or malfunction of the primary protection and its backup protection. This false tripping is particularly serious since it may result in isolating larger healthy areas of the network. Unfortunately, this error is normally not considered during optimal overcurrent coordination. Simulation tests are carried out for validation purposes using the ATP/EMTP. Similarly, the current transformers (CTs) saturation impact on fault location for the practical parallel network configuration is evaluated. This cause inaccurate fault location computation which is normally disregarded during the calculation of the fault distance. A comparative study of the most common algorithms for compensating Current Transformer (CT) saturation is presented using some selected algorithms based on different mathematical cores. A detailed CT simulation platform is utilized using the practical CT modeling in the ATP-EMTP. To avoid these expected problems of miss-coordination or malfunction of primary protection and its associated backup protection due to the CT saturation, an improved compensation algorithm for CT saturation is proposed. Then, these compensated errors can be incorroborated into the fault location process. Owing to the importance of realizing an accurate voltage and current measurements, an efficient current tracking method of power frequency signals using Rogowski coil is proposed. In order to compensate the output signal of the Rogowski coil, a direct and simplified digital compensation technique is proposed to reconstruct the input current. The proposed measuring concept is performed by processing its terminal voltage using the discrete Fourier transform (DFT). Both experimental and simulation verification tests are applied. An experimental system is also proposed for the optical current transducer. The basic principle for this transducer is the faraday rotation of light beam through Terbium Gallium Garnet (TGG) which called a crystal material in the presence of an external magnetic field coaxial with the light. There is no doubt that Successful fault diagnosis systems are essential for implementing practical self-healing procedures in automated distribution systems. Successful fault diagnosis effectively decrease repairing times by precise detecting and locating the deteriorated components in distribution networks. Evaluating the reliability of the overall fault diagnosis system will enable the efficacy of the improved measuring transducer to be assessed in modern distribution systems. This reliability is assessed using Markov model analysis for a selected typical practical distribution system. The reliability analysis is computed using dynamic distribution network measurements for the selected distribution system according to the most common IEEE reliability indices. Reliability improvement is evaluated by incorporating modern self-healing procedures in the automatic restoration for distribution networks. Self-healing impact on the reliability evaluation is investigated revealing the automation role for enhancing the network reliability and service continuity.