Method and circuitry for detecting faults in field oriented controlled permanent magnet synchronous machines

A fault detection unit comprising:

• a threshold detector for:
• receiving at least two outputs from a proportional-integral-derivative (PID) regulator, wherein the at least two outputs comprise at least two rotor reference frame currents, and
• determining a magnitude of an amplitude for each of the at least two rotor reference frame currents;
• a detection signal generation unit for generating a detection signal based on the at least two rotor reference frame currents, wherein the detection signal identifies a single amplitude magnitude value based on the magnitudes of the amplitudes for each of the at least two rotor reference frame currents;
• and
• a comparator for comparing the single amplitude value with an amplitude threshold value to identify an existence of a permanent magnet motor fault.

A method comprising:

• receiving at least two outputs from a proportional-integral-derivative (PID) regulator, wherein the at least two outputs comprise at least two rotor reference frame currents;
• determining a magnitude of an amplitude for each of the at least two rotor reference frame currents;
• generating a detection signal based on the at least two rotor reference frame currents, wherein the detection signal identifies a single amplitude magnitude value based on the magnitudes of the amplitudes for each of the at least two rotor reference frame currents;
• and
• identifying an existence of a permanent magnet motor fault based on a comparison between the single amplitude magnitude value and an amplitude threshold value.