Gm Global Technolgoy Operations, Inc.

Chia-Chou Yeh

Steven E Schulz

Daniel J Berry

Paul F Turnbull

Brian A Welchko

Khwaja M Rahman

Nitinkumar R Patel

Peter James Savagian

Yo Chan Son

Bon Ho Bae

Mohammad N Anwar

Pankaj Mithal

Jianglin Wang

An inverter electrically operatively connected to an electric machine and in communication with a controller is described. The inverter is electrically connected to a high-voltage DC power bus. A method for controlling the multi-phase inverter circuit includes monitoring, via the controller, a rotational speed of the electric machine during operation of the inverter in an over-modulation mode. The inverter is commanded to operate in a linear modulation mode when the rotational speed is within a speed range associated with objectionable audible noise generated by operating the electric machine in the over-modulation mode.

Method and apparatus for controlling an electric machine

An electric motor powers a fluidic pump fluidly connected to a hydraulic circuit. Operating the electric motor includes determining a heat transfer coefficient for the electric motor based upon a temperature of hydraulic fluid in the hydraulic circuit. A temperature of the electric motor is determined based upon the heat transfer coefficient. Operation of the electric motor is controlled based upon the temperature of the electric motor.

Method and apparatus for controlling an electric motor employed to power a fluidic pump

Methods and systems are provided for determining a temperature of a motor of a vehicle having an ignition when the ignition is turned on following a period of time in which the ignition had been turned off. An amount of time for which the vehicle had been turned off is determined. A motor temperature model is run using a time step to simulate the amount of time for which the vehicle had been turned off to determine an initial value of the temperature of the motor.

Vehicle motor temperature determination

Methods, systems, and vehicles are provided pertaining to the determination of a temperature of a vehicle motor having an ignition when the ignition is turned on following a period of time in which the ignition had been turned off. A memory stores a function having a boundary condition that comprises a prior temperature from when the ignition was turned off. A processor is coupled to the memory. The processor is configured to determine an amount of time for which the ignition has been turned on and determine the temperature of the motor using the function if the amount of time for which the ignition has been turned on is less than a predetermined threshold.

Methods and systems are provided for diagnosing faults of a rotor of an electric motor. A current is obtained for an inverter using a sensor. A preliminary angle is determined by a control unit or processor using a resolver angle of the rotor. A transformation is conducted by the control unit or processor using a transformation angle that is equal to a multiplier multiplied by the preliminary angle. A fault condition is identified via the control unit or processor using the transformation.

Methods and systems for diagnosing faults for rotors of electric motors

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.

Electric motor stator winding temperature estimation

A vehicle includes a power source, a motor, and a computing device. The power source provides electrical energy to the motor, and the motor generates rotational motion from the electrical energy received. The computing device is configured to estimate a temperature of the motor in real time based at least in part on a thermal model of the motor. The thermal model includes a plurality of nodes and at least one thermal resistance. Each node represents a region of the motor and each thermal resistance represents a heat transfer path between at least two of the nodes. A method includes solving one or more energy balance equations to determine a temperature change at each node and estimating the temperature of the motor in real time based at least in part on the temperature change at each node and at least one of the thermal resistances in the thermal model.

Motor temperature estimation based on thermal model

An electric motor system includes an electric motor comprising a stator with windings and a rotor configured to operate at a motor speed; a cooling system comprising coolant configured to cool the rotor and the stator, the coolant having a coolant flow rate and a coolant temperature; an inverter module coupled to the electric motor and configured to provide current to the windings based on inverter control signals; a current regulated torque controller coupled to the inverter module and configured to generate the inverter control signals in response to a derated torque command; and a temperature estimation controller coupled to the current regulated torque controller and configured to generate the derated torque command based on an initial torque command and an estimated stator winding temperature. The temperature estimation controller is configured to estimate the estimated stator winding temperature based on the motor speed and the coolant flow rate.

Electric motor stator winding temperature estimation systems and methods

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.

Methods and systems for diagnosing stator windings in an electric motor

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.

Methods and systems for performing fault diagnostics for rotors of electric motors

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.

Estimating rotor angular position and velocity and verifying accuracy of position sensor outputs

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.

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Gardena, CA, United States of America

Chia-Chou Yeh