Elliptical novelty grouping for on-line short-turn detection of excited running rotors

A technique for the detection of shorted turns in the field-windings of ope rating synchronous turbine-generators is described. The measuring method us ed is the twin-signal sensing method, where pulses are injected into each t erminal of the. rotor, The reflected signals are subtracted to produce a si gnature signals that contains information about the rotor's state, The sign ature signals are! sampled and accepted or rejected as valid based on an ou tlier detection criteria, Novelty detection is applied to the accepted sign als. The current signature signal is compared to a range of signature signa ls taken when the rotor was known. to. be free of shorts, If the current si gnature signal strays too far from the known healthy signal, the signature signal is 'novel' and the possibility of a short is declared. The method wa s tested on a running test rotor with voltage excitation, A comparison of m ethods shows that an elliptical novelty grouping algorithm gives highly acc urate results.