Abstract: The concepts described herein provide a method, apparatus, and system for controlling an inverter by modifying duty cycles of the PWM control signals in a manner that achieves a minimum duration between consecutive switching events in the inverter, which serves to reduce common mode current in the bearing(s) of an attached rotary electric machine. To minimize the effect of additional current and voltage ripple into the system, the minimum switching duration is defined in relation to a modulation index and geometric location near the sector boundaries of the respective inverter voltage space vector diagram.

Abstract: A control system for a rotary electric machine includes an inverter including a plurality of power switches, a heat exchanger, first temperature sensors arranged to monitor the power switches, a second temperature sensor arranged to monitor the heat exchanger, and a controller. An expected power loss is determined based upon electric current, switching functions, and electrical characteristics of the power switches. A plurality of power capacity terms are determined based upon the expected power loss in the inverter, the temperatures of the power switches, and the temperature of the heat exchanger. The inverter is controlled based upon the aforementioned power capacities.

Abstract: A cooling system for a drivetrain of an electric vehicle includes a coolant circuit directing a flow of coolant through a first inverter and a second inverter of the drivetrain, and an adjustable flow valve positioned along the coolant circuit to selectably alter proportions of the flow of coolant directed through each of the first inverter and the second inverter. A method of operating a cooling system for a first inverter and a second inverter of a vehicle drivetrain includes commanding a speed and torque of each of the first and second inverter, and estimating losses and temperature of each of the first inverter and the second inverter as a result of the commanded speed and torque. A valve position of an adjustable flow valve operably connected to the first inverter and the second inverter is selected, and a change of the valve position is commanded.

Abstract: The disclosure includes a control system for a multi-phase electric machine that includes an inverter configured to transfer electric energy from a rechargeable energy storage device (RESS), and phase current sensors. A controller includes an executable instruction set to monitor, via the phase current sensors, the phase currents, and detect that one of the phase currents is outside a linear measurement range of a respective one of the phase current sensors. An extrapolated current for the respective one of the phase current sensors is determined based upon the phase currents from others of the phase current sensors. A current extrapolation routine evaluates the respective one of the phase current sensors. A fault is detected in the respective one of the phase current sensors based upon the current extrapolation routine and the extrapolated current.

Abstract: An electric drive system, method and apparatus includes a rechargeable energy storage unit, a power inverter, and a rotary electric machine. Transfer of electrical power between the rechargeable energy storage unit and the rotary electric machine is governed by a pulse width modulation (PWM) switching frequency, which is one of a non-six-step switching mode or a six-step switching mode. Executable instructions determine a rotational speed, a torque command, a torque direction, a bus voltage, and a hysteresis band, determine a modulation index command in response to the rotational speed, the torque command, the torque direction, and the bus voltage, and command operation of the rotary electric machine in one of the non-six-step switching mode or the six-step switching mode employing the modulation index command.

Abstract: The disclosure includes a control system for a multi-phase electric machine that includes an inverter configured to transfer electric energy from a rechargeable energy storage device (RESS), and phase current sensors. A controller includes an executable instruction set to monitor, via the phase current sensors, the phase currents, and detect that one of the phase currents is outside a linear measurement range of a respective one of the phase current sensors. An extrapolated current for the respective one of the phase current sensors is determined based upon the phase currents from others of the phase current sensors. A current extrapolation routine evaluates the respective one of the phase current sensors. A fault is detected in the respective one of the phase current sensors based upon the current extrapolation routine and the extrapolated current.

Abstract: An electric drive unit includes a polyphase alternating current (AC) motor, an inverter. A motor controller employs field oriented controls to achieve torque and heat production objectives for the electric drive unit. Additional heat may be generated through inverter operation control.

Abstract: Presented are motor control systems, vehicles, and methods for generating motor heat while holding an offset motor torque during stationary vehicle operation. A method of operating an AC motor includes a resident or remote vehicle controller receiving a mode request to operate a vehicle in a stationary mode, and a temperature request including the AC motor generating motor heat during the stationary operating mode. The controller determines an offset motor torque to generate the motor heat and hold the AC motor's output member at a select position when operating the vehicle in the stationary mode. Using a DQ transform model of the AC motor, the controller selects multiple dq current trajectories located in respective dq operating quadrants of the DQ transform model based on the offset motor torque. The controller then commands a power inverter to transmit electrical current to the AC motor based on the select dq current trajectories.

Abstract: Presented are high-voltage electrical systems, control logic, and electric-drive vehicles with optimized motor torque output. A method of operating an electric-drive vehicle includes a controller identifying the vehicle's operating mode and determining calibration settings corresponding to this operating mode. These calibration settings include low and high coolant temperature (CoolTemp) thresholds, and motor-calibrated torque limits as a function of CoolTemp. The controller determines if the present CoolTemp of the power inverter's coolant is greater than the low CoolTemp threshold and less than the high CoolTemp threshold. If so, the controller sets a motor torque limit of the vehicle's electric motor to a torque limit value selected from a fixed torque limit region within the torque limits data between the low and high CoolTemp thresholds.

Abstract: Control of an AC motor includes rotation over an operating speed range with the output from an inverter by operating the inverter at switching frequencies that vary in proportion to rotor speed. The operating speed range is parsed into a plurality of speed regions and the switching frequencies within each operating speed region may correspond to a respective pulse ratio that is different from the respective pulse ratio corresponding to an adjacent speed region.

Abstract: An electric drive system, method and apparatus includes a rechargeable energy storage unit, a power inverter, and a rotary electric machine. Transfer of electrical power between the rechargeable energy storage unit and the rotary electric machine is governed by a pulse width modulation (PWM) switching frequency, which is one of a non-six-step switching mode or a six-step switching mode. Executable instructions determine a rotational speed, a torque command, a torque direction, a bus voltage, and a hysteresis band, determine a modulation index command in response to the rotational speed, the torque command, the torque direction, and the bus voltage, and command operation of the rotary electric machine in one of the non-six-step switching mode or the six-step switching mode employing the modulation index command.

Abstract: An electric drive unit includes a polyphase alternating current (AC) motor, an inverter. A motor controller employs field oriented controls to achieve torque and heat production objectives for the electric drive unit. Additional heat may be generated through inverter operation control.

Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. The electric motor includes a stator and a rotor with one or more permanent magnets. A controller is in communication with the electric motor and has recorded instructions for a method for minimizing demagnetization in the one or more permanent magnets. The controller is adapted to select a starting point and an intermediate point on a current trajectory in a stator current graph. The controller is adapted to obtain a final point on the stator current trajectory based on a comparison of the intermediate point and a predetermined voltage limit. A demagnetized torque capability is generated based on the final point on the current trajectory.

Abstract: A method for increasing a default electric stall torque limits in a motor vehicle having an electrified powertrain inclusive of a traction power inverter module (TPIM) connected to an electric traction motor includes receiving vehicle level inputs via a controller. The controller is programmed with the default electric stall torque limits. The method includes selecting an inverter control strategy, via the controller, as a selected inverter control strategy in response to the vehicle level inputs, the strategy including temporarily increasing the default electric stall torque limits while applying a pulse width modulation (PWM) type at a corresponding PWM switching frequency. The method also includes controlling an output state of the TPIM and the electric traction motor over a calibrated duration, via the controller, using the selected inverter control strategy. A motor vehicle includes the controller, road wheels, TPIM, and traction motor.

Abstract: An electric drive system includes a rechargeable energy storage unit, a power inverter, an electric motor and a controller having a processor and tangible, non-transitory memory on which instructions are recorded. A transfer of electrical power between the rechargeable energy storage unit and the electric motor is governed by a pulse width modulation (PWM) switching frequency. The controller is configured to determine a current switching frequency based in part on a PWM type, a PWM switching frequency style and an inverter direct current voltage. A PWM scalar is determined based in part on the current switching frequency and a maximum value of a control reference frequency. The controller is configured to transmit a command signal to regulate the transfer of electrical power based in part on the PWM scalar, the PWM switching frequency being proportional to a product of the PWM scalar and the control reference frequency.

Abstract: A novel power inverter system for transferring electric power between a DC power source and a multi-phase electric machine is described, and includes a power inverter, a Z-source inverter, a first switch, and a second switch. The first switch is arranged between positive and negative conductors of a high-voltage bus that is electrically coupled to the DC power source, and the second switch is arranged in-line on the positive conductor of the high-voltage bus.

Abstract: An electric drive system includes a rechargeable energy storage unit, a power inverter, an electric motor and a controller having a processor and tangible, non-transitory memory on which instructions are recorded. A transfer of electrical power between the rechargeable energy storage unit and the electric motor is governed by a pulse width modulation (PWM) switching frequency. The controller is configured to determine a current switching frequency based in part on a PWM type, a PWM switching frequency style and an inverter direct current voltage. A PWM scalar is determined based in part on the current switching frequency and a maximum value of a control reference frequency. The controller is configured to transmit a command signal to regulate the transfer of electrical power based in part on the PWM scalar, the PWM switching frequency being proportional to a product of the PWM scalar and the control reference frequency.

Abstract: Presented are high-voltage electrical systems with optimized pulse width modulation (PWM) control, methods for making/using such systems, and vehicles with enhanced electric drive capabilities via PWM type and frequency control. A method of operating an electrical system includes an electronic controller determining a PWM region layout with multiple PWM regions arranged in a torque-speed curve calibrated to an electric motor and power inverter. The controller selects one of the PWM regions based on a speed and torque of the motor, and selects a PWM type based on this selected PWM region. The controller selects a PWM switching frequency style based on the selected PWM region, and selects a PWM switching frequency based on the selected PWM region, switching frequency style, and PWM type. The controller commands a power inverter to regulate transfer of electrical power between a rechargeable battery and the motor based on the PWM type and switching frequency.

Abstract: An apparatus and a method for controlling operation of a vehicle includes a controller having a processor and a tangible, non-transitory memory. The vehicle includes a park assembly with a park actuator motor having an actuator shaft. The vehicle has a park mode and an out-of-park mode. The controller is configured to determine if the park actuator motor has reached an out-of-park position when a shift command to the out-of-park mode is received. The controller is configured to obtain and store at least one dynamic parameter associated with the park actuator motor prior to the detent member reaching the out-of-park position. The method includes determining a load factor based on the dynamic parameter over time when at least one of a predefined time threshold and a predefined motor position threshold is reached. Operation of the vehicle is controlled based at least partially on the load factor.

Abstract: A method for increasing a default electric stall torque limits in a motor vehicle having an electrified powertrain inclusive of a traction power inverter module (TPIM) connected to an electric traction motor includes receiving vehicle level inputs via a controller. The controller is programmed with the default electric stall torque limits. The method includes selecting an inverter control strategy, via the controller, as a selected inverter control strategy in response to the vehicle level inputs, the strategy including temporarily increasing the default electric stall torque limits while applying a pulse width modulation (PWM) type at a corresponding PWM switching frequency. The method also includes controlling an output state of the TPIM and the electric traction motor over a calibrated duration, via the controller, using the selected inverter control strategy. A motor vehicle includes the controller, road wheels, TPIM, and traction motor.