Hybrid engine system with transient load assistance

• US 20090186741A1
• Filed: 01/18/2008
• Published: 07/23/2009
• Est. Priority Date: 01/18/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Si, Baojun Peter, Mei, Berry, Lane, William Henry, Barngrover, Michael John
• Granted Patent: US 8,348,804 B2
• Time in Patent Office: Days
• US Class Current: 477/3
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60W 10/06 including control of combustion engines
• 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 2510/0623 Fuel flow rate
• CPC Class Codes: B60W 2510/0628 Inlet air flow rate
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 2530/211 Fuel quality, e.g. water content due to age of fuel
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A power train is provided having a power source for generating a power output. The power train also has a power storage device for storing and distributing power. The power train further has a controller configured to cause the distribution of power from the power storage device for assisting the power source when the rate of fuel entering the power source is above a threshold fuel rate. The threshold fuel rate is a fuel rate at which, assisting the power source increases the efficiency of the power train.

Claims

1. A power train, comprising:

a power source for generating a power output;

a power storage device for storing and distributing power; and

a controller configured to cause the distribution of power from the power storage device for assisting the power source when the rate of fuel entering the power source is above a threshold fuel rate, the threshold fuel rate being a fuel rate at which, assisting the power source increases the efficiency of the power train.

2. The power train of claim 1, wherein the controller is configured to determine an amount of power currently stored in the power storage device and an amount of power currently being generated by the power source.

3. The power train of claim 2, wherein the controller is configured to cause the power storage device to distribute power when the fuel rate is above the threshold fuel rate and the amount of power stored in the power storage device is greater than the difference between the amount of power currently being generated by the power source and a desired power output.

4. The power train of claim 3, wherein the controller is configured to prevent the distribution of power from power storage device when the power available from the power storage device is less than the difference between the amount of power currently being generated by the power source and the desired power output.

5. The power train of claim 4, wherein the threshold fuel rate is a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

6. The power train of claim 5, wherein the controller is configured to prevent the fuel rate from increasing when the fuel rate is above the threshold fuel rate.

7. The power train of claim 4, wherein the threshold fuel rate is a rate below a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

8. The power train of claim 7, wherein the controller is configured to prevent the fuel rate from increasing when the fuel rate is above the fuel limit.

9. A method for operating a power train, comprising:

sensing a first parameter indicative of a rate of fuel entering a power source;

sensing a second parameter indicative of an amount of power generated by the power source; and

distributing power from a power storage device to assist the power source when the rate of fuel entering the power source is above a threshold fuel rate, the threshold fuel rate being a fuel rate at which, assisting the power source increases the efficiency of the power train.

10. The method of claim 9, wherein the threshold fuel rate is a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

11. The method of claim 10, further including preventing the fuel rate from increasing when the fuel rate is above the threshold fuel rate.

12. The method of claim 11, wherein the threshold fuel rate is a rate below a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

13. The method of claim 12, further including preventing the fuel rate from increasing when the fuel rate is substantially the same as or above the fuel limit.

14. A method for operating a power train, comprising:

receiving an input from an operator requesting a desired power output;

sensing a first parameter indicative of a rate of fuel entering a power source;

sensing a second parameter indicative of an amount of power generated by the power source;

sensing a third parameter indicative of an amount of power stored in a power storage device; and

distributing power from the power storage device when the amount of power stored in the power storage device is greater than the difference between the amount of power currently being generated by the power source and the desired power output, and the fuel rate is above a threshold fuel rate, the threshold fuel rate being a fuel rate at which, assisting the power source increases the efficiency of the power train.

15. The method of claim 14, further including preventing the distribution of power from power storage device when the power available from the power storage device is less than the difference between the amount of power currently being generated by the power source and the desired power output.

16. The method of claim 15, further including regulating the distribution of power from the power storage device so that the combined power from the power source and the power storage device is substantially the same as the desired power output.

17. The method of claim 16, wherein the threshold fuel rate is a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

18. The method of claim 17, further including preventing the fuel rate from increasing when the fuel rate is above the threshold fuel rate.

19. The method of claim 16, wherein the threshold fuel rate is a rate below a fuel limit of the power source, the fuel limit being the fuel rate above which, less than all of the fuel entering the power source is combusted.

20. The method of claim 19, further including preventing the fuel rate from increasing when the fuel rate is above the fuel limit.