SYSTEMS AND METHODS FOR DETECTING HIGH-IMPEDANCE FAULTS IN A MULTI-GROUNDED POWER DISTRIBUTION SYSTEM

摘要

The apparatus and methods calculate a plurality of sum of differences for a power distribution system quantity with a sum of difference filter, provide a set of predetermined blocking conditions, provide a trending and memory with an output, generate a set threshold with an adaptive tuning algorithm; establish a reference based upon the plurality of power distribution quantities differences from the one-cycle difference filter and the set threshold, calculate a ratio of the difference between the plurality of sum of differences from the sum of difference filter and the reference, memorize a time and form a trend output if the ratio of the difference exceeds the set threshold, and determine the existence of a high-impedance fault with decision logic based on the trend output and the set of predetermined blocking conditions.