Deere + Company

Robert B Shaw

Long Wu

Zimin W Vilar

Tianjun Fu

Chris J Tremel

Alan K Gilman

Srujan Kusumba

Kent D Wanner

Neal D Clements

David Michael Loken

John D Paulson

Jeffrey Gerald Hopman

David Holmburg

Jiyao Wang

Brian Frederick Boeshans

Jacob R DeCock

Wei Xu

Vilar W Zimin

A first inverter has a set of first output phases coupled to a grid voltage source. A second inverter has a set of second output phases coupled to the grid voltage source. A phase measurement device is adapted to measure at least one reference phase of the grid voltage source at a reference phase point. An electronic data processor is configured to: determine an observed phase difference between the reference phase point and an observed position sample of a pulse-width-modulation carrier signal of the first inverter, the second inverter, or each parallel-coupled inverter; determine a target phase difference between the reference phase point and target position sample of the pulse-width-modulation carrier signal; determine a frequency adjustment to the pulse-width-modulation carrier signal of the first inverter, the second inverter, or all parallel-coupled inverters, based on a difference between the observed phase difference and the target phase difference.

System and method for frequency adjustment of parallel inverters coupled to a grid power source

A temperature estimation module estimates each junction temperature of a corresponding semiconductor device, among a plurality of semiconductor devices, for each phase of an inverter. The temperature estimation module or the data processing system determines a hottest device with a highest junction temperature among the semiconductor devices. A thermal adjustment module or data processing system determines if the highest junction temperature parameter is less than maximum junction temperature parameter for the respective semiconductor device or deciding whether or not to adjust a duty cycle of the semiconductor devices.

Method and inverter with thermal management for controlling an electric machine

In one example embodiment, a motor control unit includes a processor configured to tune a current regulator regulating a supply of electrical current to an electric motor by determining a plurality of variables, the plurality of variables including a stator resistance value, a first inductance value and a second inductance value, the stator resistance value being a resistance value of a stator of the electric motor, the first inductance value being a d-axis inductance of the electric motor and the second inductance value being a q-axis inductance of the electric motor. The processor is further configured to tune the current regulator by determining a plurality of gains based on the determined plurality of variables and generating current commands for operating the electric motor based on the determined plurality of gains.

Method and apparatus for auto-tuning an electric machine current regulator

Provided is a method and controller for controlling a vehicle dc bus voltage. The method includes generating a parameter. The parameter is based on a reference dc bus voltage squared. The method includes controlling the vehicle dc bus voltage based on the parameter and a detected dc bus voltage. The method may also include generating another parameter based on a power demand associated with at least one of a motoring mode operation and a generating mode operation of a traction motor associated with the vehicle. The power demand is indicated in a message received via a dedicated high speed data bus. The method includes controlling the vehicle dc bus voltage based on the another parameter.

DC bus voltage control

At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a voltage for the motor at a stationary reference frame, the voltage having a frequency and the measured current being based on the voltage, a filter configured to obtain position information of the rotor based on the measured current and a nonlinear observer configured to estimate a rotor position of the motor during the stationary reference frame based on the position information. The controller is configured to control the motor based at least in part on the estimated rotor position.

Methods of determining initial position of a rotor and systems thereof

While enforcing a fake position in the data processing system and applying a zero direct-axis current command, positive and negative quadrature-axis current commands are applied sequentially and at approximately same magnitude to urge the rotor toward an enforced position. A processing module measures a positive quadrature-axis current aligned raw position data after application of the positive quadrature-axis current command and measures negative quadrature-axis current aligned raw position data for the rotor after application of the negative quadrature-axis command. An initial position offset calibrator or data processor determines a difference between the raw position data to determine an alignment of a true averaging axis. An initial position offset calibrator or data processor determines a raw averaging axis position data based on an average of the raw position data. An initial position offset calibrator or data processor determines a position offset based on a difference between the determined true averaging axis and the determined raw averaging axis position data.

Method and system for calibrating rotor position offset of an electric motor

A data storage device stores previous position readings of the rotor for a previous cycle of a pulse width modulation signal applied to the motor. A current raw position reading for the current cycle is received. A predicted position reading for a current cycle is determined based on at least one of the stored previous position readings of the previous cycle. A data processor determines whether a difference between the current raw position reading and the predicted position reading for a first mode and a second mode is within one or more preset thresholds. The data processor selects the current raw position reading as a verified reliable final position reading if a first difference for the first mode is equal to or less than a primary preset threshold or if a second difference for the second mode is equal to or less than a secondary preset threshold.

Method and system for determining a position of a rotor of an electric motor with noise reduction

One embodiment of the method includes setting up a testing architecture where the testing architecture includes a test IPM machine having an output shaft coupled to an output shaft of a secondary speed control machine. The method further includes controlling the secondary speed control machine to drive the output shaft of the test IPM machine at a first desired speed, determining a pair of desired direct and quadrature axis currents for each of a plurality of peak current magnitudes, and recording characterization data associated with each pair of desired direct and quadrature axis currents. The controlling, determining and recording steps for each of a second through nth desired speeds may be repeated. Control lookup tables for operation of an IPM machine may be generated from the characterization data.

Method and apparatus for characterizing an interior permanent magnet machine

A sensor detects position data for a rotor of the motor at a first time. A data processor receives the detected position data associated with a first time delay. A sensing circuit senses an analog current at the motor during a second time delay. An analog-to-digital converter converts the analog current to a digital current data during a third time delay. The fourth time delay is detected between actual current reading instant and position reading instant in a data processor. The digital phase current data is transformed into measured direct and quadrature axes control current data based on synchronization or temporal alignment of the position data with the actual measured analog phase current at the starting time by compensating the position data by a sum of the second time delay, the third time delay and the fourth time delay, where the first time delay is subtracted from the sum.

Method and system for controlling an electric motor with compensation for time delay in position determination

A data processor determines whether a composite torque command is larger than a preset torque threshold for a time interval. The composite torque command is convertible into a direct-axis current command and a quadrature-axis current command. The data processor determines whether a rotor speed of the motor is less than a preset speed threshold for the time interval. The data processor, the current adjustment module, or the current shaping module adjusts the direct-axis current command and the quadrature-axis current command to obtain a revised direct-axis current command and revised quadrature-axis current command for the time interval if the composite torque command is larger than the preset torque threshold and if the rotor speed is less than the preset speed threshold, where the revised current commands vary by the detected rotational position of the rotor to achieve a generally constant shaft torque output.

Method and system for controlling an electric motor at or near stall conditions

A pair of direct d-q-axis voltage commands is associated with a monotonically varying test sequence of test rotor angular positions to determine a correct rotational direction of a rotor of the motor in response to application of the pair of direct d-q-axis voltage commands to the motor. The rotor of the motor rotates (e.g., self spins in a diagnostic mode) in response to the applied direct d-q-axis voltage commands and applied monotonically varying test sequence of test rotor angular positions. The primary positioning module or data processor determines that conductor connections between the inverter (e.g., motor controller) and the motor are correct if the calculated shaft speed sign is positive with respect to an applied monotonically varying test sequence of rotor angular positions that monotonically increases.

Method and system for evaluating electrical connections between a motor controller and motor

Example embodiments disclose an Interior Permanent Magnet (IPM) machine system including an IPM machine including a nominal operating direct current (dc) bus voltage, and a controller configured to detect an operating dc bus voltage of the IPM machine and to control the IPM machine based on the nominal operating dc bus voltage and the detected operating dc bus voltage.

Interior permanent magnet machine systems and methods for controlling interior permanent magnet machines

A temperature estimation module estimates a change in temperature of the magnets associated with the rotor of the motor based on an operational magnetic flux strength that is compared to a reference magnetic flux strength determined at a known ambient temperature and for a predetermined operating range of the motor The temperature estimation module or the system establishes a relationship between the estimated change in the temperature and a magnetic torque component of a target output torque of the motor consistent with the predetermined operating range. The current adjustment module or the system adjusts a command (e.g., quadrature-axis current command) for the motor to compensate for shaft torque variation associated with the estimated change in the temperature in conformance with the established relationship.

Method and system controlling an electrical motor with temperature compensation

A method calibrates a current sensing instant to latch a current value from a set of current signals. A current command including a magnitude at a Gamma angle is provided to control a motor when the motor is operating in a motoring mode at a shaft speed. A matching current command including a same magnitude at a same Gamma angle is provided to control the motor when the motor is operating in a braking mode at a same shaft speed. A first actual averaging rms current magnitude of three phase currents of the motor is monitored when the motor is controlled by the current command and operating in the motoring mode. A second actual averaging rms current magnitude of the three phase currents of the motor is monitored when the motor is controlled by the matching current command and operating in the braking mode. A current sensing instant is adjusted until an observed first actual averaging rms current magnitude in the motoring mode equals an observed second actual averaging rms current magnitude in the braking mode.

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Moorhead, MN, United States of America

Robert B Shaw