Abstract: A method for controlling transient operation of a rotary electric machine in an electric powertrain or other electrical system includes, during a shunt angle transition occurring during a maximum torque per ampere (MTPA) control region, determining an estimated output torque of the electric machine via a torque estimation block using d-axis and q-axis current commands and an additional value, i.e., an actual shunt angle or a machine temperature. The method includes subtracting the estimated output torque from a commanded output torque to derive an adjusted commanded torque value or torque error, and calculating, from the torque error, a delta d-axis current command and a delta q-axis current command. The method includes adjusting d-axis and q-axis current commands using the delta commands to produce adjusted d-axis and q-axis current commands, which are then used as closed-loop feedback control terms by the torque estimation block.

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.

Abstract: A method for controlling transient operation of a variable flux machine (VFM) includes, during a shunt angle transition, receiving a commanded and measured shunt angle when operating in a predetermined operating region, e.g., maximum torque per ampere or field weakening. The method includes calculating d-axis and q-axis delta current terms (?Id and ?Iq) required to maintain an output torque level of the VFM through a duration of the shunt angle transition, then applying the required ?Id and ?Id terms as feed-forward terms to adjust a d-axis current (Id) term and a q-axis current (Iq) term from a respective lookup table. In this manner the controller maintains the output torque level of the VFM during the shunt angle transition. An electric powertrain includes the VFM, a TPIM, and the controller. A PM machine may be controlled by substituting temperature for shunt angle.

Abstract: A method for controlling transient operation of a rotary electric machine in an electric powertrain or other electrical system includes, during a shunt angle transition occurring during a maximum torque per ampere (MTPA) control region, determining an estimated output torque of the electric machine via a torque estimation block using d-axis and q-axis current commands and an additional value, i.e., an actual shunt angle or a machine temperature. The method includes subtracting the estimated output torque from a commanded output torque to derive an adjusted commanded torque value or torque error, and calculating, from the torque error, a delta d-axis current command and a delta q-axis current command. The method includes adjusting d-axis and q-axis current commands using the delta commands to produce adjusted d-axis and q-axis current commands, which are then used as closed-loop feedback control terms by the torque estimation block.

Abstract: A DC-DC power converter including switched inductance circuits arranged in parallel is described. Operation includes determining a commanded current and activation commands for the switched inductance circuits based upon the commanded current. This includes executing the activation commands and monitoring current in the switched inductance circuits. An average measured current is determined for each of the switched inductance circuits, and a modified activation command is determined for each of the switched inductance circuits based upon the average measured current. A time portion of the modified activation command that exceeds an end time point of a subsequent time period is determined, and the modified activation commands for the switched inductance circuits are executed, including forward-shifting that time portion of the modified activation command for each of the switched inductance circuits that exceeds the end time point.

Abstract: A DC-DC power converter including switched inductance circuits arranged in parallel is described. Operation includes determining a commanded current and activation commands for the switched inductance circuits based upon the commanded current. This includes executing the activation commands and monitoring current in the switched inductance circuits. An average measured current is determined for each of the switched inductance circuits, and a modified activation command is determined for each of the switched inductance circuits based upon the average measured current. A time portion of the modified activation command that exceeds an end time point of a subsequent time period is determined, and the modified activation commands for the switched inductance circuits are executed, including forward-shifting that time portion of the modified activation command for each of the switched inductance circuits that exceeds the end time point.

Abstract: A cascaded inverter system is described and includes an electric machine that is electrically connected in series between first and second inverters. A controller is in communication with the first and second inverters, and includes an executable instruction set. A first dead-time compensation term and a first voltage compensation term are determined based upon an initial phase current and a switching frequency for the first inverter, and a final first duty cycle is determined based thereon. Simultaneously, a second dead-time compensation term and a second voltage compensation term are determined based upon the inverted initial phase current and a switching frequency for the second inverter, and a final second duty cycle is determined based thereon. Operation of the first and second inverters are dynamically controlled based upon the final first duty cycle and the final second duty cycle, respectively.

Abstract: A magnetization state control method for a variable magnetization machine, the method includes generating a flux linkage vector while changing a magnetization state of the variable magnetization machine such that a trajectory of the flux linkage vector has a curved clockwise trajectory on a dq-axis plane and a magnitude of the flux linkage vector temporally changes, with the dq-axis plane being a synchronous reference frame with a d-axis pointing in a direction of a permanent magnet flux and a q-axis being 90 degrees ahead of the d-axis in a rotational direction of a rotor.

Abstract: A variable magnetization machine control system comprising a controller configured to generate a reversely rotating d-axis/q-axis current vector trajectory during a change in a magnetization state of a variable magnetization machine to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.

Abstract: A DC-DC power converter is described, and includes switched inductance circuits arranged in parallel, current sensors disposed to monitor one of the switched inductance circuits, and a controller. The DC-DC power converter supplies electric power originating from a DC power source to a high-voltage bus. Control and operation includes determining a desired control mode for operating the DC-DC power converter, wherein the desired control mode includes one of a voltage control mode and a current control mode. A desired voltage and a desired differential current for operating the DC-DC power converter are determined based upon the desired control mode. A desired current for operating the DC-DC power converter is determined based upon the desired differential current. Operation of the DC-DC power converter is controlled in the desired control mode based upon the desired voltage and the desired current.

Abstract: A cascaded inverter system is described and includes an electric machine that is electrically connected in series between first and second inverters. A controller is in communication with the first and second inverters, and includes an executable instruction set. A first dead-time compensation term and a first voltage compensation term are determined based upon an initial phase current and a switching frequency for the first inverter, and a final first duty cycle is determined based thereon. Simultaneously, a second dead-time compensation term and a second voltage compensation term are determined based upon the inverted initial phase current and a switching frequency for the second inverter, and a final second duty cycle is determined based thereon. Operation of the first and second inverters are dynamically controlled based upon the final first duty cycle and the final second duty cycle, respectively.

Abstract: A variable magnetization machine control system comprising a controller configured to adjust a d-axis current waveform and a q-axis current waveform in accordance with an operating condition of a variable magnetization machine to generate an adjusted d-axis current waveform and an adjusted q-axis current waveform that provide a driving voltage to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.

Abstract: A current regulator is provided for an electric machine drive system for driving an electric machine. The current regulator includes an adjustable damping module that has a value of virtual damping resistance that is applied at the current regulator. The value of virtual damping resistance is adjustable as a function of sampling frequency. A controller can control the current regulator by determining whether the sampling frequency has changed since a previous execution cycle of the current regulator, and when the sampling frequency has changed since the previous execution cycle, the controller can modify the damping value as a function of the sampling frequency to allow the damping value to change with the sampling frequency. The damping value has a new value of virtual damping resistance that is applied at the current regulator after modifying the damping value. The controller can then execute the current regulator in accordance with the modified damping value to generate the voltage commands.

Abstract: A current regulator is provided for an electric machine drive system for driving an electric machine. The current regulator includes an adjustable damping module that has a value of virtual damping resistance that is applied at the current regulator. The value of virtual damping resistance is adjustable as a function of sampling frequency. A controller can control the current regulator by determining whether the sampling frequency has changed since a previous execution cycle of the current regulator, and when the sampling frequency has changed since the previous execution cycle, the controller can modify the damping value as a function of the sampling frequency to allow the damping value to change with the sampling frequency. The damping value has a new value of virtual damping resistance that is applied at the current regulator after modifying the damping value. The controller can then execute the current regulator in accordance with the modified damping value to generate the voltage commands.

Abstract: A current regulator is provided for an electric machine drive system for driving an electric machine. The current regulator is configurable to operate in a first configuration or a second configuration depending on a synchronous speed of the electric machine. A controller can configure an operational mode of the current regulator by selecting, based on the synchronous speed of the electric machine, either the first configuration of the current regulator or the second configuration of the current regulator as a currently active configuration, and can then execute the current regulator in accordance with the currently active configuration. The first configuration of the current regulator comprises a first set of elements and cross-coupling gain blocks, whereas the second configuration of the current regulator can include the first set of elements without the cross-coupling gain blocks.

Abstract: A magnetization state control method for a variable magnetization machine, the method includes generating a flux linkage vector while changing a magnetization state of the variable magnetization machine such that a trajectory of the flux linkage vector has a curved clockwise trajectory on a dq-axis plane and a magnitude of the flux linkage vector temporally changes, with the dq-axis plane being a synchronous reference frame with a d-axis pointing in a direction of a permanent magnet flux and a q-axis being 90 degrees ahead of the d-axis in a rotational direction of a rotor.

Abstract: A variable magnetization machine control system comprising a controller configured to adjust a d-axis current waveform and a q-axis current waveform in accordance with an operating condition of a variable magnetization machine to generate an adjusted d-axis current waveform and an adjusted q-axis current waveform that provide a driving voltage to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.

Abstract: A variable magnetization machine control system comprising a controller configured to generate a reversely rotating d-axis/q-axis current vector trajectory during a change in a magnetization state of a variable magnetization machine to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.