The Identification And Location Of The Voltage Sag Source In Distribution System

In this paper, the concept of the voltage sag source and the detection method are described briefly. Based on the comparison of the current methods, comply with the idea that the event source identification consists of event source locating and event source kind identification, wavelet transform combined with the PNN model is adapted, which construct a classifier to identify the three main causes: line fault, induction motor starting and transformer energizing. Thereafter, the location of the sources can be determined accordingly.The criterion of fault line and phase selection can be used to determine the fault line and type, while the fault location can be figured out by utilizing traveling wave. The reflected traveling wave from the fault point is identified by comparing the polarities of wavelet transform modulus maxima when the fault refers to ground. As to the other two causes, the rules to determine the relative location are proposed briefly.At last, the paper attempts to design an equipment of fault location system by using virtual instrument developing software. Both the hardware and software's fundamental functions are presented.