US Patent 11467213 Defect detector in power distribution system

A defect detector can receives voltage data characterizing a three-phase voltage for each of a plurality of feeder lines. The defect detector generates an alert indicating that a potential defect exists at a switch upstream of the plurality of feeder lines in response to the voltage data indicating (i) a drop in two or more phases of voltage at a given feeder line of the plurality of feeder lines occurred within a predetermined amount of time of toggling of the switch or (ii) a drop in two or more phases of voltage on at least two or more feeder lines of the plurality of feeder lines has occurred.