Abstract: Methods, system and apparatus are provided for reducing power loss in an electric motor drive system that includes an electric machine and an inverter module. A controller determines whether a torque command (Tcmd) is less than a minimum torque threshold (Tmin) that is required to disable the inverter module, and if so, increments a counter and determines whether the torque command (Tcmd) remains less than the minimum torque threshold (Tmin). When the torque command (Tcmd) remains less than the minimum torque threshold (Tmin), the controller checks to determine whether a current count value (n) maintained at the counter is greater than a count threshold (nth), and if so, the controller can generate a disable signal to disable switching within the inverter module.

Abstract: Methods and systems are provided for assessing a vehicle transmission having a resolver. A memory is configured to store preliminary data pertaining to an error of the resolver. A processor is coupled to the memory, and is configured to determine a harmonic characteristic of the preliminary data, and to assess the vehicle transmission using the harmonic characteristic.

Abstract: A method for operating a powertrain system including a torque machine mechanically coupled to an internal combustion engine includes, upon detecting a pending fault associated with a power switch configured to control power flow to the torque machine, disabling torque output from the torque machine and executing retry events. The retry events are iteratively executed with a debounce time period preceding each retry event. Presence of a fault associated with the power switch is detected when a quantity of the retry events during a time window exceeds a threshold.

Abstract: Embodiments of the present disclosure relate to methods, systems and apparatus for adjusting current and/or torque commands used to control operation of an asynchronous machine based on rotor flux of the asynchronous machine.

Abstract: A powertrain system includes an electric motor/generator unit. Upon detecting an open high-voltage switch associated with a high-voltage DC electrical bus, low-voltage electrical power is employed to energize the high-voltage DC electrical bus, control parameters are adjusted to operate the electric motor/generator unit in a fault tolerant electric generation mode, an internal combustion engine is operated to spin the electric motor/generator unit, and the electric motor/generator unit is operated in the fault tolerant electric generation mode.

Abstract: Methods and systems are provided for motor torque control for hybrid vehicles having a motor and a communications bus. The motor torque is controlled using a first motor torque capacity if the communications bus is healthy. The motor torque is controlled using a second motor torque capacity if the communications bus is unhealthy. The first motor torque capacity has a first absolute value. The second motor torque capacity has a second absolute value that is less than the first absolute value.

Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.

Abstract: Methods, system and apparatus are provided for reducing power loss in an electric motor drive system that includes an electric machine and an inverter module. A controller determines whether a torque command (Tcmd) is less than a minimum torque threshold (Tmin) that is required to disable the inverter module, and if so, increments a counter and determines whether the torque command (Tcmd) remains less than the minimum torque threshold (Tmin). When the torque command (Tcmd) remains less than the minimum torque threshold (Tmin), the controller checks to determine whether a current count value (n) maintained at the counter is greater than a count threshold (nth), and if so, the controller can generate a disable signal to disable switching within the inverter module.

Abstract: A method for operating a powertrain system including a torque machine mechanically coupled to an internal combustion engine includes, upon detecting a pending fault associated with a power switch configured to control power flow to the torque machine, disabling torque output from the torque machine and executing retry events. The retry events are iteratively executed with a debounce time period preceding each retry event. Presence of a fault associated with the power switch is detected when a quantity of the retry events during a time window exceeds a threshold.

Abstract: In accordance with exemplary embodiments, rotor temperature estimation is provided for estimating rotor temperatures of an electric motor in an electric vehicle. A method comprises estimating a rotor temperature in a controller for an electric motor of a vehicle using a fast-mode rotor temperature estimator for a time interval, and then deactivating the fast-mode rotor temperate estimator after the time interval and activating a normal-mode rotor temperature estimator in the controller for the electric motor of the vehicle. A system comprises an electric motor, a resistance rotor temperature estimator including a limit value limiting a temperature estimate increase for temperature estimates, and a controller for the electric motor, which uses the temperature estimate and is configured to temporarily increase the limit value of the resistance rotor temperature estimator providing a fast-mode rotor temperature estimate.

Abstract: Methods and systems for controlling motor torque in a hybrid vehicle are provided. A current sensor provides a feedback current when the sensor is operating properly. A processor controls the motor torque using the feedback current if the current sensor is operating properly. The processor controls the motor torque using a slip value for the hybrid vehicle if the current sensor is not operating properly.

Abstract: A method is provided for controlling an induction motor having a rotor. The method includes receiving a torque command; comparing the torque command to a threshold torque value; generating, with a first estimation module, a first estimated rotor resistance when the torque command is less than or equal to the threshold torque value; generating, with a second estimation module, a second estimated rotor resistance when the torque command is greater than the threshold torque value; and generating control signals for the induction motor based on the first estimated rotor resistance or the second estimated rotor resistance.

Abstract: A powertrain system includes an electric motor/generator unit. Upon detecting an open high-voltage switch associated with a high-voltage DC electrical bus, low-voltage electrical power is employed to energize the high-voltage DC electrical bus, control parameters are adjusted to operate the electric motor/generator unit in a fault tolerant electric generation mode, an internal combustion engine is operated to spin the electric motor/generator unit, and the electric motor/generator unit is operated in the fault tolerant electric generation mode.

Abstract: A control system is provided for an inverter assembly associated with an induction motor. The system includes a current determination module configured to generate q- and d-axis current commands based on a torque command. The current determination module is further configured to generate the q-axis current command based on an observed flux linkage and a flux linkage command. The system further includes a motor current control module coupled to the current determination module and configured to generate q- and d-axis voltage commands based on the q- and d-axis current commands generated by the current determination module and a PWM modulator coupled to the motor current control module configured to generate duty cycle signals for operating the inverter assembly based on the q- and d-axis voltage commands generated by the motor current control module.

Abstract: A control system for a hybrid powertrain includes an engine start detector that detects when an engine of the hybrid powertrain is activated via an electric motor during an auto start. An electric motor speed monitor determines a first speed of the electric motor for a first time and a second speed of the electric motor for a second time after detection of the engine in an active state. A control module determines a rate of change in speed of the electric motor based on the first speed and the second speed. The control module adjusts torque output of the electric motor during startup of the engine and based on the rate of change in speed.

Abstract: A method for monitoring an electrically-powered torque machine configured to generate torque in a hybrid powertrain system includes monitoring signal outputs of a resolver configured to monitor rotational position of the torque machine. Upon detecting a fault warning state associated with the signal outputs of the resolver, a motor torque capacity of the torque machine is derated. Upon a clearing of the fault warning state, a torque ramp-up state to increase the motor torque capacity of the torque machine is executed. Notice of an incidence of a fault associated with the signal outputs of the resolver is provided only when the motor torque capacity fails to achieve a threshold motor torque capacity within a threshold recovery time period while executing the torque ramp-up state.

Abstract: A method of processing a resolver fault in a motor generator unit (MGU) includes receiving a position signal from a resolver describing a measured angular position of a rotor of the MGU, determining the presence of the resolver fault using the position signal, and calculating or extrapolating an estimated rotor position when the resolver fault is determined. A predetermined resolver fault state may be determined using a measured duration of the resolver fault, and the MGU may be controlled using the estimated rotor position for at least a portion of the duration of the resolver fault. A motor control circuit is operable for processing the resolver fault using the above method, and may automatically vary a torque output or a pulse-width modulation (PWM) of the MGU depending on the duration of the resolver fault.

Abstract: Methods and systems are provided for detecting loss of isolation of a motor, connections, or phase cables while an AC motor is operating. The system includes a power supply that is substantially isolated from the ground or chassis having a power supply voltage, and a power inverter electrically coupled to the power supply. The power inverter is configured to provide AC current from the power supply in an AC phase at an AC terminal, with the phase having current at a fundamental frequency that controls the motor speed. An electric motor is electrically coupled to the AC terminal of the power inverter and has a chassis that is substantially electrically isolated from the AC terminal of the power inverter under normal operating conditions. A processor is configured to control the AC current provided by the power inverter. The processor is configured to receive a first voltage signal related to current flowing through a motor chassis.

Abstract: In a motor controller, a modified interpolation technique uses an extrapolated torque command for the upper table to improve torque linearity under certain conditions. When the torque command input is greater than the max torque limit of a first look-up table, but less than the maximum torque limit of a second, adjacent look-up table, the desired current command is computed by interpolating between the maximum torque limit of the first table and a revised torque value for the second look-up table, wherein the revised torque value is determined by extrapolating from the maximum torque limit of the first look-up table through a torque value based on the torque command input.

Abstract: Methods and systems are provided for assessing a vehicle transmission having a resolver. A memory is configured to store preliminary data pertaining to an error of the resolver. A processor is coupled to the memory, and is configured to determine a harmonic characteristic of the preliminary data, and to assess the vehicle transmission using the harmonic characteristic.