Method and apparatus for determining the operating condition of generator rotating diodes

A power circuit configured to monitor an operating condition of rotating diodes within a rotating rectifier for a rotating field circuit inductively coupled to a stationary armature circuit of a generator providing power for a drive motor of an electric drive system in a machine, the electric drive system including a prime mover disposed to provide an output coupled with the generator, the power circuit comprising:

• a rectifier circuit having an input interface coupled to a multiphase output of the stationary armature circuit of the generator;
• a DC link, coupled to an output interface of the rectifier circuit, the DC link having a DC link voltage defined between a first DC rail and a second DC rail;
• and
• a controller configured to perform the steps of:
• receiving a set of inputs including:
• a set of generator inputs, a set of machine parameters associated with the machine, and a set of diagnostic values associated with the generator,
• determining, based on the set of inputs, for the DC link coupled to the output of the rectifier circuit, an expected operating value and an actual operating value,
• comparing the expected operating value with the actual operating value to provide a difference, and
• setting a flag indicating a malfunction condition for one or more of the rotating diodes within the rotating rectifier for the rotating field circuit of the generator when a magnitude of the difference exceeds a threshold.