Abstract: An electric motor controller having fault detection comprises: a driver circuit configured to drive an electric motor in response to a received speed demand signal; a measurement circuit configured to measure current through windings of the electric motor, the measurement circuit comprising a back emf, BEMF, observer configured to determine an estimated BEMF value, a BEMF error threshold and an estimated rotor angular speed value from the measured currents; a detector circuit configured to receive the rotor speed demand signal, the estimated BEMF value, the BEMF error threshold, the estimated rotor angular speed value and a measured rotor speed from a rotor speed sensor on the electric motor and to detect a fault in the electric motor controller if the estimated BEMF value lies outside the BEMF error threshold and the measured rotor speed is within a defined rotor speed error threshold.

Abstract: The disclosure relates generally to the field of electric motors, and in particular to fault detection in an electric motor controller.

Abstract: A method and apparatus are provided for controlling a sensorless multi-phase permanent magnet (PM) motor by sensing induced motor terminal voltages from the PM motor while the rotor is spinning, generating an input voltage vector signal from the plurality of induced motor terminal voltages, projecting the input voltage vector signal to a transformed voltage vector signal which does not include DC-offset components by using a Clarke transformation without a zero component that is applied to the input voltage vector signal, and estimating an initial rotor position of the rotor from the transformed voltage vector signal, wherein said sensing, projecting, and estimating are performed while a power converter for the sensorless multi-phase PM motor is disabled.

Abstract: A method and apparatus are provided for controlling a sensorless multi-phase permanent magnet (PM) motor by sensing induced motor terminal voltages from the PM motor while the rotor is spinning, generating an input voltage vector signal from the plurality of induced motor terminal voltages, projecting the input voltage vector signal to a transformed voltage vector signal which does not include DC-offset components by using a Clarke transformation without a zero component that is applied to the input voltage vector signal, and estimating an initial rotor position of the rotor from the transformed voltage vector signal, wherein said sensing, projecting, and estimating are performed while a power converter for the sensorless multi-phase PM motor is disabled.

Abstract: A system for a power switch of a multiphase power converter coupled to an inductive load including a test controller, a voltage sampling circuit, a processing circuit, and a converter. A test pulse is applied to power switches of the converter to generate a test current through the inductive load, which forward biases a body diode of a power switch during a freewheel portion after the test pulse is completed. The voltage across the body diode is sampled during the freewheel portion, and the voltage samples are converted to a voltage value and a slope value. The voltage and slope values are converted to an estimated temperature value based on a characterization of the inductive load and the body diode. The conversion may be performed by a lookup table that stores an estimated temperature value for each unique combination of the voltage and slope values.

Abstract: A system for a power switch of a multiphase power converter coupled to an inductive load including a test controller, a voltage sampling circuit, a processing circuit, and a converter. A test pulse is applied to power switches of the converter to generate a test current through the inductive load, which forward biases a body diode of a power switch during a freewheel portion after the test pulse is completed. The voltage across the body diode is sampled during the freewheel portion, and the voltage samples are converted to a voltage value and a slope value. The voltage and slope values are converted to an estimated temperature value based on a characterization of the inductive load and the body diode. The conversion may be performed by a lookup table that stores an estimated temperature value for each unique combination of the voltage and slope values.