Abstract: Systems and methods are provided for identifying a fault condition in stator windings in an electric motor. A method comprises applying a first signal at a first electrical angle to the stator windings and measuring a second signal from the stator windings in response to the first signal. The method further comprises determining a measured response for the electric motor at the first electrical angle based on the second signal and obtaining a nominal response for the electric motor at the first electrical angle. A fault condition is identified when a magnitude of the difference between the measured response and the nominal response is greater than a threshold value.

Abstract: A method for fault diagnosis for a rotor of an electric motor, the electric motor also having a stator, includes the steps of generating, via a processor, a measured motor current for the stator, determining, via the processor, a resolver angle of the rotor, determining, via the processor, a flux angle of the rotor, calculating, via the processor, a transformation angle using the resolver angle and the flux angle, conducting, via the processor, a transformation of the motor current using the transformation angle, and identifying, via the processor, a fault condition based on the transformation.

Abstract: A temperature estimation controller and methods are provided for estimating stator winding temperature over a full range of motor operating speeds. In one implementation, the angular velocity of a motor is determined along with a total power loss for each phase of said motor. The total power loss in each phase comprises stator winding power loss and a core power loss. Stator winding temperatures for each phase of motor can then estimated based on the total power loss in that phase, and a combined thermal impedance for that phase. The combined thermal impedance comprises a first thermal impedance between the stator winding and the stator core, and a second thermal impedance between the stator core and the motor coolant.

Abstract: Methods, system and apparatus are provided for estimating rotor angular position and angular velocity during a position sensor fault, and for verifying the accuracy or inaccuracy of a position sensor's outputs based on the estimated rotor angular position and angular velocity of the rotor following a position sensor fault.

Abstract: Systems and methods are provided for diagnosing stator windings in an electric motor operating under control of a current-regulating control loop. The current-regulating control loop is configured to provide a command voltage to the electric motor. The command voltage comprises a current-regulated voltage based on a difference between a commanded current and a measured current through the stator windings. The method comprises determining a negative sequence component of the command voltage, and identifying a fault condition when a characteristic of the negative sequence component is greater than a threshold value.

Abstract: Systems and methods are provided for identifying a fault condition in stator windings in an electric motor. A method comprises applying a first signal at a first electrical angle to the stator windings and measuring a second signal from the stator windings in response to the first signal. The method further comprises determining a measured response for the electric motor at the first electrical angle based on the second signal and obtaining a nominal response for the electric motor at the first electrical angle. A fault condition is identified when a magnitude of the difference between the measured response and the nominal response is greater than a threshold value.