Methods and systems for diagnosing stator windings in an electric motor
AssigneeGM Global Technology Operations LLC
InventorsChia-Chou Yeh, Steven E. Schulz, Mohammad N. Anwar
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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.
Claims18
An electrical system for use in a vehicle, the electrical system comprising:
- an electric motor having stator windings;
- an energy source;
- an inverter module coupled between the energy source and the stator windings, the inverter module being configured to provide a commanded voltage from the energy source to the stator windings of the electric motor;
- a plurality of current sensors coupled between the inverter module and the stator windings, the plurality of current sensors being configured to measure current through the stator windings, resulting in measured current;
- and
- a control module coupled to the inverter module and the plurality of current sensors, the control module being configured to:
- obtain a current command corresponding to a commanded current for the stator windings of the electric motor;
- generate a voltage command corresponding to the commanded voltage based on a difference between the measured current and the commanded current;
- determine a negative sequence voltage for the stator windings based on the voltage command;
- and
- identify a fault condition in the stator windings based on a characteristic of a DC component of the negative sequence voltage.
A method for diagnosing stator windings in an electric motor in a vehicle, the method comprising:
- generating a voltage command for the stator windings, the voltage command being configured to regulate current through the stator windings to a commanded value;
- determining a negative sequence voltage based on the voltage command;
- determining a DC component of the negative sequence voltage;
- and
- identifying a fault condition based on a characteristic of the DC component of the negative sequence voltage.
A method for diagnosing stator windings in an electric motor operating under control of a current-regulating control loop, the current-regulating control loop being configured to provide a command voltage to the electric motor, the command voltage comprising a current-regulated voltage based on a difference between a commanded current and a measured current through the stator windings, the method comprising:
- transforming the command voltage from a positive synchronous reference frame to a negative synchronous reference frame, resulting in a negative synchronous reference frame voltage;
- determining a DC component of the negative synchronous reference frame voltage;
- and
- identifying a fault condition when a characteristic of the DC component is greater than a threshold value.
Dependencies are inferred from the claim text.