EXPERT SYSTEM FOR DETECTING HIGH IMPEDANCE FAULTS

An expert detection system includes a method and apparatus for detecting high impedance faults occurring on a distribution circuit coupled to an AC power source. Based upon an expert's knowledge of high impedance fault behavior and the performance of various fault detection techniques, the expert forms a belief as to whether a high impedance fault has indeed occurred. The expert's beliefs may be adjusted with an elliptic formula, and then used to weight the status output of each technique. The weighted multiple technique outputs are combined to determine whether a high impedance fault has occurred. The expert's beliefs are calibrated during initial start-up by comparison with a confirmed performance history of the detector using a scoring rule. The belief calibration may be included during operation to provide on-line adaption of the expert detector to the changing situations of the distribution circuit.