Abstract: Methods and apparatus are provided for a limp home operational mode for an electric motor system. The method includes determining whether a resolver has failed. When the resolver has not failed, operation of the electric motor system uses resolver signals. When the resolver fails, operation of the electric motor system uses sensorless rotor position and rotor speed signals.

Abstract: Methods, system and apparatus are provided for sensorless control of a vector controlled motor drive system that includes an electric motor used to drive an auxiliary oil pump.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. As a result, torque linearity is maintained when the electric machine operates in the field weakening region.

Abstract: Methods and apparatus are provided for sensorless control of a permanent magnet motor. The method includes the step of determining a sensorless position signal and a sensorless speed signal in a torque-speed plane in response to phase currents corresponding to currents on one or more of the plurality of phases.

Abstract: Methods and apparatus are provided for startup of a permanent magnet alternating current (AC) motor. The method comprises the steps of detecting startup of the permanent magnet AC motor; detecting a mechanical oscillation of the permanent magnet AC motor when startup of the permanent magnet AC motor is detected; and, in response to detection of the mechanical oscillation of the permanent magnet AC motor when startup is detected, suppressing the mechanical oscillation of the permanent magnet AC motor.

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 low speed sensorless rotor angular position estimation that implements reduced switching loss PWM waveforms.

Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. First and second voltage commands are used at the field weakening loop to generate a first adjusting current command. The first adjusting current command is then provided to the torque linearity control loop, where it is multiplied by a gain to generate an output current command, which can then be limited to generate a second adjusting current command. The second adjusting current command can then be added to a current command to generate an adjusted current command. The first adjusting current command can also be added to another current command to generate another adjusted current command. The adjusted current commands and feedback currents are then used at a synchronous current regulator to generate new first and second voltage commands.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an IPM machine. The systems and methods adjust the q-axis and the d-axis components of the stator current commands of the IPM machine using a flux weakening and a torque linearity control loop respectively. Thereby, torque linearity is maintained during the field weakening region of operation of the IPM machine.

Abstract: According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux ?*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.

Abstract: Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and introducing predetermined error on the estimated reference axis. The method further includes the steps of determining if a speed of the permanent magnet motor is greater than a predetermined threshold speed and setting the control reference axis to 180° added to the estimated reference axis if the speed of the permanent magnet motor is greater than the predetermined threshold speed or setting the control reference axis to the estimated reference axis if the speed of the permanent magnet motor is less than or equal to the predetermined threshold speed.

Abstract: A method and system for operating an automotive electric motor having first and second components is provided. A desired frequency of vibration for the electric motor is selected. A current is caused to flow through at least one of the first and second components such that the second component moves relative to the first component. The current is modulated such that the motor vibrates at the desired frequency.

Abstract: A method and system for limiting the operating temperature of an electric motor is provided. A maximum operational temperature of the motor is determined. A current operational temperature within the motor is sensed. A maximum allowable power dissipation of the motor is calculated based at least in part on the maximum operational temperature and the current operational temperature of the motor. A torque command for the motor is generated based on the maximum allowable power dissipation.

Abstract: Methods and apparatus are provided for startup of a permanent magnet alternating current (AC) motor. The method comprises the steps of detecting startup of the permanent magnet AC motor; detecting a mechanical oscillation of the permanent magnet AC motor when startup of the permanent magnet AC motor is detected; and, in response to detection of the mechanical oscillation of the permanent magnet AC motor when startup is detected, suppressing the mechanical oscillation of the permanent magnet AC motor.

Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.

Abstract: Permanent magnet alternating current (PMAC) motor systems and methods for starting or restarting PMAC motor system sensorless control algorithms are provided. One system includes a PMAC motor including a rotor, an inverter, and a controller. The controller includes control logic, start/restart logic, drive logic, current detect logic, and estimation logic configured to estimate a position of the rotor, a speed of the PMAC motor, or both based on current detected in each phase of the inverter. A start/restart method includes determining to start/restart the sensorless control algorithm and modifying the inverter voltage in response to the determined start/restart. The method also includes detecting current in each inverter phase after the inverter voltage is modified and estimating a rotor position, a PMAC motor speed, or both based on the current detected in each inverter phase after the inverter voltage is modified. Another controller includes means for performing the above start/restart method.

Abstract: Methods and systems for controlling an electric motor are provided. A signal comprising at least first and second cycles is provided to the electric motor. A first flux value for the electric motor associated with the first cycle of the signal is calculated. A second flux value for the electric motor associated with the second cycle of the signal is calculated based on the first flux value.

Abstract: According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux ?*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.

Abstract: A method and system for limiting the operating temperature of an electric motor is provided. A maximum operational temperature of the motor is determined. A current operational temperature within the motor is sensed. A maximum allowable power dissipation of the motor is calculated based at least in part on the maximum operational temperature and the current operational temperature of the motor. A torque command for the motor is generated based on the maximum allowable power dissipation.