fault section estimation

Distribution network is a part of power systems’ general structure which is considered as the last chain in energy generation and transmission to the consumers. One of the most important issues in distribution lines is occurrence of a fault; regarding the innate structure of distribution networks and their numerous branches, fault location is of high importance. Impedance methods are the most common way used to locate the fault. This method faces problems such as multi-response properties, not being able to recognize the correct fault section and not being able to provide a single correct response. In the present study, possible fault locations are recognized first using the improved impedance method. Then, its natural frequencies are determined. Since there are more than one possible fault locations, it is necessary to identify the fault section in order to determine the fault location accurately. The fault section and its main location are determined through simulating the fault in each section of possible locations by small steps and through accommodating the determined frequency to the existing natural frequency registered in the original fault voltage form. The aforementioned method was applied in Salim’s 11-node network in which effect of fault inception angles, effect of different resistors and fault type were tested. Accuracy and efficiency of the proposed method has been verified.

Accurate locating of fault in power distribution system (PDS) can significantly improve the reliability indices. In this paper، a new simple and practical method is proposed for estimating the section and distance of fault in PDS. In the proposed method، at first the protective devises are allocated and then specially set in such a way that they are coordinated and the unique current pattern is generated at the beginning of feeder for fault in each section. For approving and analyzing the accuracy of the proposed method، the method is tested on two test feeders and one real feeder of Bushehr Distribution Company under different fault conditions. Also، in the real test system two actual faults are applied and the section of fault is correctly determined by the proposed method.