METHOD AND APPARATUS FOR CONTROLLING A HIGH-VOLTAGE BATTERY CONNECTION FOR HYBRID POWERTRAIN SYSTEM

• US 20120056567A1
• Filed: 09/02/2010
• Published: 03/08/2012
• Est. Priority Date: 09/02/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Savagian, Peter J., Gleason, Sean E., Tarchinski, James E., Anwar, Mohammad N.
• Granted Patent: US 8,860,348 B2
• Time in Patent Office: Days
• US Class Current: 318/400.3
• CPC Class Codes: B60K 6/20 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A hybrid powertrain system has a high-voltage electric circuit including a high-voltage battery and a DC link coupled to first and second inverters electrically connected to first and second torque machines. A method for operating the hybrid powertrain system includes receiving a motor torque command for the second torque machine, determining a preferred DC link voltage for achieving the motor torque commanded from the second torque machine, selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

Claims

1. Method for operating a hybrid powertrain system including a high-voltage electric circuit comprising a high-voltage battery and a DC link coupled to first and second inverters electrically connected to first and second torque machines, the method comprising:

receiving a motor torque command for the second torque machine;

determining a preferred DC link voltage for achieving the motor torque commanded from the second torque machine; and

selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

2. The method of claim 1, wherein selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage comprises continuously interrupting the electric power flow between the high-voltage battery and the DC link when the preferred DC link voltage is greater than an output voltage of the high-voltage battery.

3. The method of claim 1, wherein selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage comprises periodically interrupting the electric power flow between the high-voltage battery and the DC link when a monitored DC link voltage is greater than a threshold voltage.

4. The method of claim 3, wherein periodically interrupting the electric power flow between the high-voltage battery and the DC link comprises controlling a switch coupled between the high-voltage battery and the DC link to selectively interrupt the electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

5. The method of claim 4, wherein controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the DC link comprises executing a pulsewidth-modulated control of the switch coupled between the high-voltage battery and the DC link to selectively interrupt the electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

6. The method of claim 3, wherein periodically interrupting the electric power flow between the high-voltage battery and the DC link comprises controlling a switch coupled across the DC link to selectively interrupt the electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

7. The method of claim 6, wherein controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the DC link comprises executing a pulsewidth-modulated control of the switch coupled across the DC link to selectively interrupt the electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

8. The method of claim 1, wherein selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage comprises continuously maintaining the electric power flow between the high-voltage battery and the DC link when the preferred DC link voltage is less than an output voltage of the high-voltage battery.

9. The method of claim 1, further comprising commanding a motor torque output from the first torque machine based on a motor torque output from the second torque machine.

10. Method for operating a hybrid powertrain system including an engine and first and second torque machines coupled to a transmission device to transfer torque to a driveline and a high-voltage electric circuit including a high-voltage battery, a DC link coupled to first and second inverters electrically connected to the first and second torque machines, and a switch configured to interrupt electric power flow between the high-voltage battery and the first and second inverters when controlled to an open state, the method comprising:

commanding a motor torque output from the second torque machine in response to an operator torque request;

determining a preferred DC link voltage to achieve the commanded motor torque output from the second torque machine; and

controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the first and second inverters to achieve the preferred DC link voltage.

11. The method of claim 10, wherein controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the first and second inverters to achieve the preferred DC link voltage comprises controlling the switch to a closed state when an output voltage of the high-voltage battery is greater than the preferred DC link voltage to achieve the commanded motor torque output from the second torque machine.

12. The method of claim 10, wherein controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the first and second inverters to achieve the preferred DC link voltage comprises controlling the switch to an open state when the preferred DC link voltage to achieve the commanded motor torque output from the second torque machine is greater than an output voltage of the high-voltage battery.

13. The method of claim 10, wherein controlling the switch to selectively interrupt the electric power flow between the high-voltage battery and the first and second inverters to achieve the preferred DC link voltage comprises executing pulsewidth-modulated control of the switch when the preferred DC link voltage to achieve the commanded motor torque output from the second torque machine is greater than an output voltage of the high-voltage battery and a monitored DC link voltage is equal to or greater than a threshold voltage.

14. The method of claim 10, comprising operating the engine to transfer torque to the first torque machine to generate electric power to achieve the preferred DC link voltage.

15. The method of claim 14, further comprising commanding a motor torque output from the first torque machine responsive to the commanded motor torque output from the second torque machine.

16. The method of claim 15, comprising operating the engine to transfer torque to the first torque machine to achieve the commanded motor torque output from the first torque machine responsive to the commanded motor torque output from the second torque machine.

17. A hybrid powertrain system, comprising

an engine and first and second torque machines coupled to a transmission to transfer torque to a driveline;

a high-voltage electric circuit comprising a high-voltage battery, an inverter module, and a switch, the high-voltage battery electrically connected via a DC link to the inverter module, the inverter module electrically operatively connected to the first and second torque machines, and the switch configured to interrupt electric power flow between the high-voltage battery and the inverter module when controlled to an open state; and

a controller monitoring voltage of the high-voltage battery and a voltage across the DC link, determining a preferred voltage across the DC link, controlling the switch to interrupt electric power flow between the high-voltage battery and the inverter module in response to the voltage of the high-voltage battery, the voltage across the DC link, and the preferred voltage across the DC link.

18. The hybrid powertrain system of claim 17, wherein the switch is electrically coupled between the high-voltage battery and the DC link.

19. The hybrid powertrain system of claim 17, wherein the switch is electrically coupled across the DC link.

20. The hybrid powertrain system of claim 17, wherein controlling the switch to interrupt electric power flow between the high-voltage battery and the inverter module in response to the voltage of the high-voltage battery comprises pulsewidth-modulating the switch when the voltage across the DC link exceeds a threshold.