Method and apparatus to determine rotational position of an electrical machine

• US 7,999,496 B2
• Filed: 05/03/2007
• Issued: 08/16/2011
• Est. Priority Date: 05/03/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Prihoda, Patrick M., Gleason, Sean E, Schulz, Steven E.
• Primary Examiner(s): Ro; Bentsu
• Application Number:
  US11/743,901
• Publication Number:
  US 20080272717A1
• Time in Patent Office: 1,566 Days
• Field of Search: 318/139, 318/400.32, 318/400.33, 318/400.37, 318/400.38, 318/661
• US Class Current: 318/139
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/08 Electric propulsion units
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2555/20 : Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 2710/027 : Clutch torque
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: F16H 2037/0866 : Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: F16H 2037/102 : the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 : Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/106 : with switching means to provide two variator modes or ranges
• CPC Class Codes: H02P 21/18 : Estimation of position or speed
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A control system and method to determine position of a rotor relative to a stator for a synchronous multipole electrical machine is presented, including one for application on a fuel/electric hybrid powertrain for a vehicle. The machine includes a stator, a rotor, and a rotor position sensing mechanism. The control system controls the electrical machine, in conjunction with an electrical storage device and an inverter, using algorithms and calibrations which derive a rotor position based upon a sensorless position sensing technique, and determine an offset from a sensed rotor position. Electrical output from the inverter to the machine is controlled based the offset, which is stored non-volatile memory. A rotor position is derived based upon a sensorless position sensing technique during initial machine operation after startup of the machine, and includes operation in a torque-generative mode and in an electrical energy-generative mode.

Claims

1. Control system for an electric machine comprising a multi-phase multipole motor having a machine stator, and a machine rotor, comprising:

a voltage source inverter generating phase voltages applied to the electric machine in response to final voltage commands provided to the voltage source inverter;

a resolver assembly comprising a resolver rotor operably connected to the machine rotor and a resolver stator operably connected to the machine stator, said resolver stator providing an electrical signal output; and

a controller

providing stationary frame voltages,

providing stationary frame currents based upon measured phase currents from the electric machine,

summing voltage signals at a predetermined high frequency with the stationary frame voltages to generate the final voltage commands,

providing the final voltage commands to the voltage source inverter,

deriving a machine rotor position based upon the stationary frame currents and the predetermined high frequency,

measuring a resolver rotor position from the electrical signal output provided from the resolver stator,

determining an offset parameter as a difference between the derived machine rotor position and the measured resolver rotor position, and

controlling the voltage source inverter based upon the measured resolver rotor position and the offset parameter.

2. The control system of claim 1, wherein deriving the machine rotor position further comprises deriving the machine rotor position during an initial machine operation.

3. The control system of claim 2, wherein deriving the machine rotor position during the initial machine operation further comprises deriving the machine rotor position during a first second of machine operation after startup of the machine.

4. The control system of claim 2, wherein the initial machine operation comprises machine operation in a torque-generative mode and in an electrical energy-generative mode.

5. The control system of claim 1, wherein deriving the machine rotor position based upon the stationary frame currents and the predetermined high frequency comprises:

estimating synchronous reference frame currents from the stationary frame currents;

band pass filtering the synchronous reference frame currents at the predetermined high frequency;

extracting a DC component from the band pass filtered synchronous reference frame currents;

low pass filtering the DC component; and

estimating the machine rotor position as a function of the low pass filtered DC component.

6. The control system of claim 1, further comprising the controller storing the offset parameter in a non-volatile memory device.

7. The control system of claim 1, wherein the resolver stator comprises a plurality of inductive coils and the resolver rotor comprises a plurality of lobes.

8. The control system of claim 1, wherein the electric machine is operatively connected to a two-mode compound split hybrid electro-mechanical transmission.

9. The control system of claim 8, further comprising the two-mode compound split hybrid electro-mechanical transmission configured to transmit motive torque to a driveline of a vehicle.

10. Method for controlling electrical energy transmitted between an energy storage device and an electric machine comprising a multi-phase multipole motor having a machine stator, a machine rotor, and a resolver assembly comprising a resolver rotor operably connected to the machine rotor and a resolver stator operably connected to the machine stator, said resolver stator providing an electrical signal output, comprising:

deriving a machine rotor position based upon a sensorless position sensing technique, comprising;

generating phase voltages with a voltage source inverter in response to final voltage commands provided to the voltage source inverter;

applying the phase voltages to the electric machine;

providing stationary frame voltages;

providing stationary frame currents based upon measured phase currents from the electric machine;

summing voltage signals at a predetermined high frequency with the stationary frame voltages to generate the final voltage commands;

providing the final voltage commands to the voltage source inverter; and

deriving the machine rotor position based upon the stationary frame currents and the predetermined high frequency;

measuring a resolver rotor position from the electrical signal output provided from the resolver stator;

determining an offset parameter as a difference between the derived machine rotor position and the measured resolver rotor position; and

controlling electrical energy transmitted between the energy storage device and the electric machine based upon the measured resolver rotor position and the offset parameter.

11. The method of claim 10, wherein deriving the machine rotor position based upon the sensorless position sensing technique further comprises deriving the machine rotor position during initial machine operation.

12. The method of claim 11, wherein deriving the machine rotor position during the initial machine operation further comprises deriving the machine rotor position during a first second of machine operation after startup of the machine.

13. The method of claim 11, wherein the initial machine operation comprises machine operation in a torque-generative mode and in an electrical energy-generative mode.

14. The method of claim 10, further comprising storing the offset parameter in a non-volatile memory device.

15. Article of manufacture, comprising a storage medium having a computer program encoded therein for effecting a method to control electrical energy transmitted between an energy storage device and an electric machine comprising a multi-phase multipole motor having a machine stator, a machine rotor, and a resolver assembly comprising a resolver rotor operably connected to the machine rotor and a resolver stator operably connected to the machine stator, said resolver stator providing an electrical signal output, the program comprising:

code for deriving a machine rotor position based upon a sensorless position sensing technique executed during a startup of the electrical machine comprising;

code for generating phase voltages with a voltage source inverter in response to final voltage commands provided to the voltage source inverter;

code for applying the phase voltages to the electric machine;

code for providing stationary frame voltages;

code for providing stationary frame currents based upon measured phase currents from the electric machine;

code for summing voltage signals at a predetermined high frequency with the stationary frame voltages to generate the final voltage commands;

code for providing the final voltage commands to the voltage source inverter; and

code for deriving the machine rotor position based upon the stationary frame currents and the predetermined high frequency;

code for measuring a resolver rotor position from the electrical signal output provided from the resolver stator;

code for determining an offset parameter as a difference between the derived machine rotor position and the measured resolver rotor position; and

code for controlling electrical energy transmitted between the energy storage device and the electric machine based upon the measured resolver rotor position and the offset parameter.