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 method, apparatus, and control system are described for operating a multiphase motor drive system including a rotary electric machine and an inverter. An AC choke filter is arranged proximal to output leads from the inverter. A reference temperature associated with the AC choke filter is determined along with an operating point of the electric machine. Operation of the inverter is controlled based upon a temperature of the AC choke filter, the reference temperature, and an operating point of the electric machine. This includes modifying a switching frequency and a PWM type in a manner that reduces the AC choke filter temperature by reducing the occurrence of switching events to protect the AC choke filter based on temperature feedback.

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: 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: 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: 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: 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: 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: 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: 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.