| Abstract: | In restoration of a power system, appropriate steps need to be taken in early stages to avoid damage to the public caused by insufficient power supply. The first step in the restoration is the analysis of the fault that has produced the power failure. Today, a large amount of data will be available at the occurrence of a fault due to the use of advanced communication systems using digital relays and optical fibers. Such systems are intended to obtain data from the relays and circuit breakers (CBs) under operation and the voltage and current during operation and the prefault and postfault periods. This paper presents a hybrid fault analyzing expert system using data based on protective devices and phasor measurement. This system is a combination of an artificial neural network (ANN) and an expert system (ES). The ANN is used to simplify the analysis of current and voltage waveforms, which is considered difficult due to the presence of a fault resistance and the line impedance. Since a fault waveforms contains various ambiguous factors depending on the nature of the fault resistance, load current and other system parameters, the use of ANN is effective making such determinations. |
