Gm Global Technolgoy Operations, Inc.

Seoul National University

Anno Yoo

Daniel J Berry

Yo Chan Son

Dwarakanath V Simili

Brent S Gagas

Siddharth Ballal

Vinod Chowdary Peddi

Young Joo Lee

Sangyeop Kwak

Brian A Welchko

Min-Joong Kim

Seung Ki Sul

Song He

Jeffrey S Piasecki

Seung-Ki Sul

Brian J Gallert

Young J Kim

David S Ochs

Jinming Liu

Hyun-Sam Jung

Milan Ashok Vadera

Cheng Gong

Kibok Lee

Gilsu Choi

Sung-Yoon Jung

Debanjan Deep

Hyung-June Cho

Michael Duncan Swartz

Nathan Minor

Nikhil Deshpande

A method and system are contemplated for determining a final speed and position of a motor used in an electric vehicle. The final speed and position is calculated as a function of a sensed position when a resolver of a position system is available and as a function of a sensorless position when the resolver is unavailable.

Sensorless backup for motor speed and position

A system performs a method for operating a vehicle. A cable is attached between an inverter of the vehicle and a motor of the vehicle, the cable having a resistance. The inverter is operated using a first direct current (DC) reference voltage. A processor obtains a current from the motor, calculates a power factor at the inverter, obtains a resistance of the cable, determines a voltage drop between the inverter and the motor from the current, the resistance and the power factor due to a presence of the cable, determines a DC compensation voltage from the voltage drop, and adjusts the first DC reference voltage to a second DC reference voltage using the DC compensation voltage.

Method for compensating alternating current cable loss

Methods, systems, and vehicles are provided for determining a stator resistance value of an electric motor. The systems may include the electric motor including a stator and a rotor; a sensor system including configured to generate sensor data indicative of sensed operating conditions of the electric motor including a current magnitude, a current angle, a motor speed, a temperature of the stator, and a temperature of the rotor; and a controller operably coupled with the sensor system and the electric motor. The controller is configured to: determine an initial stator resistance value based on a stator reference temperature and either estimated data sensor data received from the sensor system; determine a stator temperature coefficient based on the sensor data and a stator nonlinear resistance ratio curve; and determine the stator resistance value based on the initial stator resistance value and the stator temperature coefficient.

Methods, systems, and vehicles configured for determining a stator resistance of an electric motor

A propulsion system for a device includes an electric motor configured to generate torque to propel the device. A position sensor is adapted to determine a rotor position of the electric motor. The system includes a controller having instructions recorded for determining the rotor position when a sensor fault condition is detected. The controller is adapted to selectively command injection of a voltage signal in a direct magnetic axis in a synchronous reference frame when a motor speed of the electric motor is below a predefined motor speed threshold and the sensor fault condition is detected. The rotor position is estimated based in part on a motor current response to the voltage signal. The voltage signal is defined by an alternating periodic shape having respective constant segments in each of a plurality of control periods, the respective constant segments being discontinuous between the control periods.

Propulsion system with rotor position estimation based on voltage signal

A vehicle is described that includes a multi-mode powertrain system having a first drive unit and a second drive unit. A controller is arranged to monitor the high-voltage DC power bus and is in communication with and operatively connected to first and second inverters. The controller is able to detect operation of one of the first inverter or the second inverter in an uncontrolled generating (UCG) mode, determine a driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode, and determine a compensating torque that is needed to counteract the driveline torque associated with the operating of the one of the first inverter or the second inverter in the UCG mode. The controller can further operate to detect a fault that may induce unintended lateral motion (ULM), and control torque outputs of the inverters based thereon.

Method and apparatus for controlling a multi-mode powertrain system of a vehicle

A method for controlling operation of a rotary electric machine includes receiving, via a bandwidth-partitioning harmonic compensation regulator (HCR) of a controller, a commanded torque and rotational speed of the electric machine, and calculating, via the HCR in response to enabling conditions, a dq harmonic compensation current and a dq harmonic compensation voltage for one or more predetermined harmonic orders using the commanded torque and the rotational speed. The harmonic compensation current and voltage cancel torque ripple and current ripple in the one or more predetermined harmonic orders. The method may include injecting an acoustic tone at a predetermined harmonic order. The method additionally includes adding the dq harmonic compensation current and voltage to a dq current and voltage command, respectively, to generate adjusted dq current and voltage commands. The electric machine is then controlled using the adjusted dq current and voltage commands.

Bandwidth-partitioning harmonic regulation for improved acoustic behavior of an electric drive system

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.

System and method for minimizing demagnetization in rotor magnets

A method for estimating a magnet temperature of a rotor magnet within a rotary electric machine includes, while a rotor of the electric machine is stationary, injecting a high-frequency voltage component onto a control voltage of the electric machine, via a controller, to generate an adjusted voltage command, and extracting a high-frequency component of a resulting current as an extracted high-frequency component. The method also includes calculating an inductance value of the electric machine using the extracted high-frequency component of the resulting current. The magnet temperature is estimated using the calculated inductance value and an angular position of the rotor. The method includes controlling an operation of the electric machine using the estimated magnet temperature. An electric powertrain uses the electric machine and controller noted above.

Inductance-based estimation of rotor magnet temperature

A method, system, and apparatus for controlling and regulating operation of a permanent magnet rotary electric machine including a stator and a rotor includes determining a first reactive power term associated with the electric machine based upon voltage, and determining a second reactive power term associated with the electric machine based upon flux. A first motor temperature associated with the electric machine is determined based upon the first and second reactive power terms, and power output from the permanent magnet electric machine is controlled based upon the first motor temperature.

Method and apparatus for controlling operation of a permanent magnet rotary electric machine

A resolver disposed to monitor a rotatable member is described, along with an associated method for evaluating an output signal therefrom. The method for monitoring the resolver includes supplying an excitation signal to the resolver, and monitoring, at an oversampling rate, first and second output signals from the resolver. An oversampling routine is executed to determine averages of the first and second output signals from the resolver. A demodulation angle error is determined based upon the first and second output signals from the resolver, and provided as feedback. A position of the resolver is also determined based upon the first and second output signals from the resolver.

Method and apparatus for monitoring a resolver

A propulsion system having an electric motor and corresponding method. A controller is configured to receive a torque request and selectively command the electric motor. The controller has a processor and tangible, non-transitory memory on which instructions are recorded for a method of generating an auxiliary power. The controller is configured to obtain a desired auxiliary power and a delta factor (&#x3b4;). The delta factor is set as a speed modifier (&#x394;&#x3c9;=&#x3b4;) when the cosine of an angle (&#x3b8;), between a constant torque unit vector and a decreasing voltage ellipse unit vector, is less than a predefined threshold. A modified rotor speed is obtained as a sum of an original rotor speed and a speed modifier (&#x394;&#x3c9;). The controller is configured to obtain modified stator current commands based on the modified rotor speed and torque request. The auxiliary power is generated by commanding the modified stator current commands.

Electric motor in propulsion system with auxiliary power generation

An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the B- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

Method for motor and inverter temperature control

A method for regulating operation of an induction motor having a rotor includes calculating a rotor flux angle error value, via a flux observer of a controller, using estimated d-axis and q-axis flux values of the rotor, estimating rotor position using a position observer of the controller, and calculating slip position of the rotor using d-axis and q-axis stator currents. The method also includes estimating a rotor flux angle as a function of slip position and estimated rotor position, calculating a corrected rotor flux angle by selectively adding the rotor flux angle error value to the estimated rotor flux angle, and controlling output torque of the motor using the corrected rotor flux angle. A logic switch may be used to selectively add the rotor flux angle.

Flux observer-based control strategy for an induction motor

A switching module switches between receiving a first output from a sensor and a second output from a sensor-less position detection module each indicating a rotor position error of a motor. A position determining module determines a rotor position of the motor based on an output of the switching module and generates a control signal to control a parameter of the motor. A sample and hold module operates on a sum of the output of the switching module and an output of the sample and hold module from a prior instance of switching between the first and second outputs. The position determining module scales the output of the sample and hold module using first and second gains to generate first and second scaled outputs, and generates the control signal based on the output of the switching module and the first and second scaled outputs.

Sensor-less control of an electric motor

Methods and systems for applying adaptive thermal compensation when operating a rotor of a motor are provided. The method includes: receiving a plurality of parameter data of torque and temperature of the rotor and current and voltage of the motor by a region determination module; calculating, by the region determination module from the set of parameter data, a cosine value to determine a region for applying the adaptive thermal compensation wherein the cosine value is calculated from a constant torque direction vector and a voltage limit eclipse vector derived from a functional relationship of the one or more parameter data; and applying, by a reference modification module, a modification value to incrementally modify the motor current when the motor is operating within the region determined by the region determination module for the adaptive thermal compensation.

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Rochester, MI, United States of America

Anno Yoo