Patent ID: 6172509
Filing Date: 2001-01-09
Classification: G01R

Abstract:
The disturbed electrical balance method of detecting occurrence and severity of winding turn faults in a polyphase alternating current rotating electrical machine, said method comprising the steps of:determining instantaneous current values for each phase of said polyphase electrical machine;calculating moving root-mean-square phase current values from said measured instantaneous phase current values;storing winding turn fault-free healthy operation values of said calculated root-mean-square phase currents;scaling ongoing calculated root-mean-square phase current values according to both said stored winding turn fault-free healthy operation values of said calculated root-mean-square phase currents and according to changes in a mathematical average of said calculated root-mean-square phase currents;computing a scaled current difference-based measure of fault-caused current divergence of said scaled ongoing calculated root-mean-square current values;evaluating a time-derivative of said computed scaled current difference-based measure of fault-caused current divergence; andannouncing presence of a suspected machine winding fault in response to magnitudes of said computed fault-caused current divergence and said evaluated time derivative values.