Abstract
Fault location in distribution systems is a challenging task because of the lack of homogeneity in the system and due to uncertainity in the data used for estimating the faulted sections. Fuzzy logic has widely been applied for handling uncertainities in the input data and its processing. Fuzzy logic has also been used to model human expertise and decision making capabilites and to determine the possibility of a fault on a particular section. This thesis presents the design and implementation of an operated device identification algorithm to be used as one of four modules in an automated modular scheme for fault section estimation on radial distribution systems. This algorithm will be executed in tandem with the other fault location modules that form the second stage of a three stage scheme. The operated device identification algorithm can assign section fault possibilities representing the possibility of involvement of each section of a distribution feeder in an event. The operated device algorithm uses the recorded current waveform of an abnormal event, the time-current characteristics and settings of various protective devices on a feeder, and feeder topology information as inputs. The algorithm then assigns a fault possibility value to each section of a feeder using fuzzy rules and fuzzy membership functions to compare a fault event with protective device settings and characteristics. The section fault possibility values can be superimposed on the feeder map by color coding the sections of a feeder according to their fault possibility values. This helps in easy visualization of possibly faulted sections. A detailed illustration of the results obtained from running the algorithm is presented in this thesis. They prove the effectiveness of the algorithm in locating faults in a distribution feeder. The operated device identification module was tested using real data measured at feeder substations. The results obtained by the algorithm were verified with feedback given by the utilities that owned the feeders. The results obtained from the tests were encouraging.
Manivannan, Karthick Muthu (2002). Fuzzy logic based operated device identification in power distribution systems. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2002 -THESIS -M88.