Patent ID: 6882173

Claim:
A system for detecting one or more shorted rotor turns in a field winding of an electric generator, comprising: an electrical tap for measuring a first voltage drop V f1 and a subsequent voltage drop V f2 across said field winding; an electrical shunt for measuring a first current I f1 and a subsequent current I f2 entering said field winding; an impedance-measuring circuit for determining a reference inductance L REF based on V f1 and I f1 and for determining a subsequent inductance L based on V f2 and I f2 ; a memory circuit for storing L REF ; and a data processing system for comparing L REF to said subsequent inductance L to determine whether L REF and said subsequent inductance L differ by more than a predetermined amount and for providing an alarm to indicate the presence of said one or more shorted rotor turns when L REF and said subsequent inductance L differ by more than said predetermined amount.