Date Added: Aug 2010
Several fault type classification techniques have been presented in the past. The most common techniques include under-impedance method, torque method, over-current method, frequency method and phase angle of the current sequence method. However, all of these techniques require the use of three phase current information during fault. As a result, these fault type classification techniques are confined to downstream faults classification only and are mainly for relaying purposes. Fault classification is impossible if the fault takes place in upstream or parallel feeder. However, with the increased interest in power quality studies, fault classification for power quality monitoring system is proposed in this paper. This paper will discuss the vastly varied requirements to classify faults for relaying purposes and also for monitoring purposes.