Abstract: A temperature estimation system and method for an electric motor of a vehicle include a set of sensors configured to measure a set of operating parameters of the electric motor including at least (i) phase current, (ii) speed, and (iii) coolant temperature and a controller configured to access a trained artificial neural network (ANN) temperature estimation model, using the trained ANN temperature estimation model with the set of electric motor operating parameters as inputs, estimate temperatures of a stator and a rotor of the electric motor, and control operation of the electric motor based on the estimated stator and rotor temperatures.

Abstract: A sensorless position estimation and control system and method for a permanent magnet electric motor of a powertrain system of a vehicle involve determining a reference torque to be achieved by the electric motor based on a set of vehicle operating parameters, determining a reference current magnitude to achieve the determined reference torque using a lookup table, determining current commands for the electric motor based on the determined reference current magnitude and a fixed reference current angle, injecting a high frequency voltage into a voltage control loop for the electric motor and estimating, by the controller, a position of a rotor of the electric motor thereafter, and controlling a current provided to the electric motor based on the determined current commands and the estimated rotor position.

Abstract: A system comprises a high voltage (HV) battery system connected to an HV bus, a motor generator unit (MGU) connected to the HV bus, a main contactor disposed on the HV bus between the MGU and the HV battery system such that, when the main contactor is closed, the HV battery system stabilizes a voltage of the HV bus, a low voltage (LV) battery system connected to an LV bus and configured to stabilize a voltage of the LV bus when the main contactor is open or malfunctioning, a direct current to direct current (DC-DC) converter connected to the HV bus and the LV bus, and a controller configured to (i) when the main contactor is closed, control the DC-DC converter to stabilize the LV bus voltage, and (ii) when the main contactor is open or malfunctioning, control the DC-DC converter to stabilize the HV bus voltage.

Abstract: A sensorless position estimation and control system and method for a permanent magnet electric motor of a powertrain system of a vehicle involve determining a reference torque to be achieved by the electric motor based on a set of vehicle operating parameters, determining a reference current magnitude to achieve the determined reference torque using a lookup table, determining current commands for the electric motor based on the determined reference current magnitude and a fixed reference current angle, injecting a high frequency voltage into a voltage control loop for the electric motor and estimating, by the controller, a position of a rotor of the electric motor thereafter, and controlling a current provided to the electric motor based on the determined current commands and the estimated rotor position.

Abstract: A method for controlling an electric machine of a vehicle drivetrain may include determining a rotational speed of the electric machine, determining a rotational speed of a drivetrain component other than the electric machine, and modifying a torque command to the electric machine based on a difference between the rotational speeds to dampen drivetrain vibrations.

Abstract: A system comprises a high voltage (HV) battery system connected to an HV bus, a motor generator unit (MGU) connected to the HV bus, a main contactor disposed on the HV bus between the MGU and the HV battery system such that, when the main contactor is closed, the HV battery system stabilizes a voltage of the HV bus, a low voltage (LV) battery system connected to an LV bus and configured to stabilize a voltage of the LV bus when the main contactor is open or malfunctioning, a direct current to direct current (DC-DC) converter connected to the HV bus and the LV bus, and a controller configured to (i) when the main contactor is closed, control the DC-DC converter to stabilize the LV bus voltage, and (ii) when the main contactor is open or malfunctioning, control the DC-DC converter to stabilize the HV bus voltage.

Abstract: An electric machine (e.g., motor or generator) for an electric drive system of an electric vehicle is adapted to be coupled to wheels of the vehicle for conversion between stored electrical energy and rotation of the wheels. A resolver is coupled to the electric machine having a rotor rotating with the electric machine, the resolver responding to an excitation signal to produce a position signal. A controller is coupled to the resolver to receive the position signal and coupled to the electric machine to control the conversion. The controller generates the excitation signal at a variable frequency selected as a function of an operating point of the electric machine to avoid harmonic noise peaks propagating at the electric machine. Consequently, the position signal is relatively less affected by electromagnetic noise.

Abstract: A drive system for an electric vehicle includes an input capacitor selectably coupled to a DC power source (e.g., battery) by a contactor. A variable voltage converter couples the input capacitor to a main link capacitor, and an inverter couples the main capacitor to a machine load (e.g., motor and/or generator). During a normal or emergency shutdown, the contactor is opened. In order to quickly discharge the input capacitor when the contactor opens, A) the converter operates in a boost mode to transfer charge from the input capacitor to the main capacitor until the input capacitor discharges to less than a threshold voltage, B) the converter deactivates to prevent transferring charge from the main capacitor to the input capacitor, and C) the main capacitor can then be discharged through the inverter.

Abstract: Systems, apparatus, and methods detect a current sensor error in an FOC electric machine system. A voltage command is monitored to detect the presence of an ac component that indicates that an error has occurred at a current sensor. For example, a sensor fault detection module can be configured to determine the deviation between an actual voltage command and an ideal voltage command to provide a complex deviation vector. By transforming the deviation vector to a reference frame rotating at the fundamental frequency of the command voltage, a dc component of the positive and negative sequences can be filtered, and their amplitudes determined. Error detection can be based on the total amplitude of the fundamental component, determined by positive and negative component amplitudes. Sensor error detection enables an FOC system to operate with two current sensors, rather than three, and provides a dedicated fault diagnostic for a current sensor.

Abstract: An electric machine (e.g., motor or generator) for an electric drive system of an electric vehicle is adapted to be coupled to wheels of the vehicle for conversion between stored electrical energy and rotation of the wheels. A resolver is coupled to the electric machine having a rotor rotating with the electric machine, the resolver responding to an excitation signal to produce a position signal. A controller is coupled to the resolver to receive the position signal and coupled to the electric machine to control the conversion. The controller generates the excitation signal at a variable frequency selected as a function of an operating point of the electric machine to avoid harmonic noise peaks propagating at the electric machine. Consequently, the position signal is relatively less affected by electromagnetic noise.

Abstract: A drive system for an electric vehicle includes an input capacitor selectably coupled to a DC power source (e.g., battery) by a contactor. A variable voltage converter couples the input capacitor to a main link capacitor, and an inverter couples the main capacitor to a machine load (e.g., motor and/or generator). During a normal or emergency shutdown, the contactor is opened. In order to quickly discharge the input capacitor when the contactor opens, A) the converter operates in a boost mode to transfer charge from the input capacitor to the main capacitor until the input capacitor discharges to less than a threshold voltage, B) the converter deactivates to prevent transferring charge from the main capacitor to the input capacitor, and C) the main capacitor can then be discharged through the inverter.

Abstract: Systems, apparatus, and methods detect a current sensor error in an FOC electric machine system. A voltage command is monitored to detect the presence of an ac component can indicate that an error has occurred at a current sensor. By way of example, a sensor fault detection module can be configured to determine the deviation between an actual voltage command and an ideal voltage command to provide a complex deviation vector. By transforming the deviation vector to a reference frame rotating at the fundamental frequency of the command voltage, a dc component of the positive and negative sequences can be filtered, and their amplitudes determined. Error detection can be based on the total amplitude of the fundamental component, determined by positive and negative component amplitudes. The invention enables an FOC system to operate with two current sensors, rather than three, and provides a dedicated fault diagnostic for a current sensor.

Abstract: A method for controlling an electric machine of a vehicle drivetrain may include determining a rotational speed of the electric machine, determining a rotational speed of a drivetrain component other than the electric machine, and modifying a torque command to the electric machine based on a difference between the rotational speeds to dampen drivetrain vibrations.