METHOD AND APPARATUS TO DETERMINE ROTATIONAL POSITION OF AN ELECTRICAL MACHINE

• US 20080272717A1
• Filed: 05/03/2007
• Published: 11/06/2008
• 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: Schulz, Steven E., Gleason, Sean E., Prihoda, Patrick M.
• Granted Patent: US 7,999,496 B2
• Time in Patent Office: Days
• 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 stator, a rotor, and a rotor position sensing mechanism, comprising:

an inverter operable to transmit electrical energy between the stator of the electrical machine and an electrical storage device; and

,

a controller, operable to;

derive a rotor position based upon a sensorless position sensing technique;

determine an offset parameter between the derived rotor position and a sensed rotor position; and

,

control the inverter based upon the sensed rotor position and the offset parameter.

2. The control system of claim 1, wherein the controller operable to derive a rotor position based upon a sensorless position sensing technique further comprises the controller operable to derive the rotor position during initial machine operation.

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

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

5. The control system of claim 1, wherein the controller operable to derive a rotor position based upon a sensorless position sensing technique comprises the controller operable to:

inject a high frequency signal into the stator of the electrical machine during initial machine operation; and

,

detect a position of the rotor based upon the injected high frequency signal.

6. The control system of claim 1, wherein the controller operable to derive a rotor position based upon a sensorless position sensing technique comprises the controller operable to:

inject a high frequency signal into the stator of the electrical machine during initial machine operation;

determine a north/south polarity of the rotor; and

,

detect a position of the rotor based upon the injected high frequency signal.

7. The control system of claim 1, further comprising the controller operable to store the offset parameter in a non-volatile memory device.

8. The control system of claim 1, wherein the rotor position sensing mechanism of the electric machine further comprises a resolver stator having a plurality of inductive coils and, a lobed resolver rotor operatively attached to the rotor of the electrical machine.

9. The control system of claim 8, wherein the controller operable to control the inverter based upon the sensed rotor position and the offset parameter further comprises:

the controller operable to control electrical energy transmitted between the stator of the electrical machine and the electrical storage device based upon the offset parameter.

10. The control system of claim 9, wherein the controller operable to control the inverter further comprises the controller operable to control electrical energy input to each coil of the stator for the multi-phase multipole motor.

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

12. The control system of claim 11, further comprising the two-mode compound split hybrid electro-mechanical transmission operable to transmit motive torque to a driveline of a vehicle.

13. Method for controlling electrical energy transmitted between an energy storage device and an electric machine comprising a multi-phase multipole motor having a stator, a rotor, and a rotor position sensing mechanism, comprising:

deriving a rotor position based upon a sensorless position sensing technique;

determining an offset parameter between the derived rotor position and a sensed rotor position; and

,

controlling electrical energy transmitted therebetween based upon the sensed rotor position and the offset parameter.

14. The method of claim 13, wherein deriving rotor position based upon a sensorless position sensing technique further comprises deriving the rotor position during initial machine operation.

15. The method of claim 13, further comprising deriving the rotor position during a first second of machine operation after startup of the machine.

16. The method of claim 14, further comprising deriving rotor position during initial machine operation comprising a torque-generative mode and an electrical energy-generative mode.

17. The method of claim 13, deriving a rotor position based upon a sensorless position sensing technique comprises:

injecting a high frequency signal into the stator of the electrical machine during initial machine operation; and

,

detecting a position of the rotor based upon the injected high frequency signal.

18. The method of claim 13, wherein deriving a rotor position based upon a sensorless position sensing technique comprises:

injecting a high frequency signal into the stator of the electrical machine during initial machine operation;

determining a north/south polarity of the rotor; and

,

detecting a position of the rotor based upon the injected high frequency signal.

19. The method of claim 13, further comprising storing the offset parameter in a non-volatile memory device.

20. The method of claim 19, wherein controlling electrical energy transmitted therebetween based upon the sensed rotor position and the offset parameter further comprises:

controlling electrical energy transmitted between the stator of the electrical machine and the electrical storage device based upon the offset parameter.

21. The method of claim 20, wherein controlling electrical energy transmitted between the stator of the electrical machine and the electrical storage device further comprises controlling electrical energy input to each coil of the stator for the multi-phase multipole motor.

22. 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 stator, a rotor, and a rotor position sensing mechanism, the program comprising:

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

code for determining an offset parameter between the derived rotor position and a sensed rotor position; and

,

code for controlling phase of electrical energy input to each coil of the stator for the multi-phase multipole motor based upon the sensed rotor position and the offset parameter.