Patent ID: 7956762

Claim:
A method for diagnosing a power generation failure for a power circuit in an electric drive coupled with a prime mover, the power circuit including a rectifier circuit coupled with a power generator and disposed to provide a DC output voltage across a DC link, the method comprising: receiving at least one power generator input; receiving at least one machine parameter associated with the prime mover; receiving a set of diagnostic values associated with the DC link and the at least one power generator input; determining a set of expected operating values based on the at least one power generator input and the at least one machine parameter, the set of expected operating values corresponding to the received set of diagnostic values; comparing each diagnostic value from the set of diagnostic values to a corresponding expected operating value from the set of expected operating values to determine a difference for each diagnostic value; and setting an indicator flag that a power generation failure exists if the difference between one or more diagnostic values and a corresponding one or more expected values exceeds a threshold; wherein the power generator is a multi-phase alternating current (AC) synchronous generator having a rotating input coupled with a prime mover output, an input winding disposed to receive an excitation signal as the at least one power generator input, an output winding magnetically coupled with the input winding and disposed to provide a set of alternator phase currents to the rectifier circuit, wherein each phase current comprises one of the diagnostic values associated with the DC link.