Method for operating an electrical system

• US 7,443,048 B2
• Filed: 06/30/2005
• Issued: 10/28/2008
• Est. Priority Date: 06/30/2005
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Morrical, Brian Todd, Bernardi, John Jay, Ehrenhardt, Kevin Dee, Goldammer, Timothy Allen
• Primary Examiner(s): Sherry; Michael J
• Assistant Examiner(s): Deschere; Andrew M
• Application Number:
  US11/170,175
• Publication Number:
  US 20070005205A1
• Time in Patent Office: 1,216 Days
• Field of Search: 307/9.1, 307/10.1, 307/10.6, 307/38, 307/39, 307/41, 700/295, 700/296, 180/65.2, 180/65.8, 903/948, 318/98
• US Class Current: 307/9.1
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/12 Methods and devices for control or regulation
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A method for operating an electrical system for a machine is provided. The electrical system may include at least one power source connected to a power-distribution network. The power-distribution network may include a first portion with one or more power loads connected thereto and a second portion with one or more power loads connected thereto. The method may include repeatedly executing a load-priority cycle including operating in a first load-priority mode and subsequently operating in a second load-priority mode, during a power deficit. Operating in the first load-priority mode may include supplying power to the first and second portions of the power-distribution network, with a priority on supplying power to the first portion. Operating in the second load-priority mode may include supplying power to the first and second portions of the power-distribution network, with a priority on supplying power to the second portion.

Claims

1. A method for operating an electrical system for a machine, which electrical system includes at least one power source connected to a power-distribution network including a first portion with one or more power loads connected thereto and a second portion with one or more power loads connected thereto, the method comprising:

during a power deficit, repeatedly executing a load-priority cycle, including;

operating in a first load-priority mode, including supplying power to the first and second portions of the power-distribution network, with a priority on supplying power to the first portion of the power-distribution network; and

subsequently, operating in a second load-priority mode, including supplying power to the first and second portions of the power-distribution network, with a priority on supplying power to the second portion of the power-distribution network.

2. The method of claim 1, wherein executing the load-priority cycle includes executing the load-priority cycle only if a driving system of the machine is not operating.

3. The method of claim 2, further including:

when a prime-mover of the machine is operating, operating in the first load-priority mode continuously.

4. The method of claim 3, wherein supplying power to the first portion of the power-distribution network includes supplying power to at least one of a driving-system controller and a driving-system sensor.

5. The method of claim 4, wherein supplying power to the second portion of the power-distribution network includes supplying power to one or more components of climate-conditioning units of the machine.

6. The method of claim 3, wherein operating in the first load-priority mode includes supplying power to the first portion of the power-distribution network independent of the power demands of the power loads connected to the second portion of the power-distribution network, and supplying power to the second portion of the power-distribution network in a quantity dependent upon the power demands of the power loads connected to the first portion of the power-distribution network.

7. The method of claim 1, wherein executing the load-priority cycle includes repeatedly operating in the first load-priority mode for a predetermined period of time and subsequently operating in the second load-priority mode for a predetermined period of time.

8. The method of claim 1, wherein operating in the first load-priority mode includes supplying power to the first portion of the power-distribution network independent of the power demands of the power loads connected to the second portion of the power-distribution network, and supplying power to the second portion of the power-distribution network in a quantity dependent upon the power demands of the power loads connected to the first portion of the power-distribution network.

9. The method of claim 1, wherein executing the load-priority cycle includes supplying power from at least one of a shore power source and an auxiliary power unit to the first portion of the power-distribution network and the second portion of the power-distribution network.

10. An electrical system for a machine, comprising:

a power-distribution network, including a first portion and a second portion;

one or more power sources connected to the first portion of the power-distribution network through a power converter and connected to the second portion of the power-distribution network through a connection other than the power converter;

one or more power loads connected to the first portion of the power-distribution network;

one or more power loads connected to the second portion of the power-distribution network; and

power-supply controls configured to execute a control method including;

adjusting an output voltage at which the power converter supplies power to the first portion of the power-distribution network dependant upon power demands of one or more of the power loads connected to the second portion of the power-distribution network.

11. The electrical system of claim 10, wherein adjusting the output voltage of the power converter includes adjusting the output voltage of the power converter dependant upon an amount of power available from one or more of the power sources, in addition to the power demands of one or more of the power loads connected to the second portion of the power-distribution network.

12. The electrical system of claim 10, wherein adjusting the output voltage of the power converter includes adjusting the output voltage of the power converter dependent upon an amount of power available from one or more of the power sources and an amount of power that the power converter is supplying to the first portion of the power-distribution network, in addition to the power demands of one or more of the power loads connected to the second portion of the power-distribution network.

13. The electrical system of claim 10, wherein adjusting the output voltage of the power converter dependant upon the power demands of one or more of the power loads connected to the second portion of the power distribution network includes:

subtracting an amount of power demanded by the power loads connected to the second portion of the power-distribution network from an amount of power available from the power sources, to determine an amount of power available for the first portion of the power-distribution network; and

adjusting the output voltage of the power converter dependent upon the amount of power available for the first portion of the power-distribution network.

14. The electrical system of claim 10, wherein the power-supply controls are capable of direct, automatic control of the amount of power supplied to one or more of the power loads connected to the second portion of the power-distribution network, and the power-supply controls are incapable of direct, automatic control of the amount of power supplied to one or more of the power loads connected to the first portion of the power-distribution network.

15. The electrical system of claim 10, further including:

a battery connected to the first portion of the power-distribution network through a connection other than the power converter;

wherein the power loads connected to the first portion of the power-distribution network include at least one of a driving-system controller and a driving-system sensor; and

wherein the power loads connected to the second portion of the power-distribution network include one or more components of climate-conditioning units.

16. A machine, comprising:

a driving system;

an electrical system, including;

one or more power sources;

a power-distribution network, including a first portion connected to one or more of the power sources and a second portion connected to one or more of the power sources;

one or more power loads connected to the first portion of the power-distribution network;

one or more power loads connected to the second portion of the power-distribution network;

power-supply controls configured to execute a control method including;

when the driving system is operating, operating in a first load-priority mode, including supplying power to the first and second portions of the power-distribution network with a priority on supplying power to the first portion of the power distribution network; and

when the driving system is not operating, selectively operating in the first load-priority mode or a second load-priority mode dependent upon conditions of operation of the machine, wherein the second load-priority mode includes supplying power to the first and second portions of the power-distribution network with a priority on supplying power to the second portion of the power-distribution network.

17. The machine of claim 16, wherein the power loads connected to the first portion of the power-distribution network include at least one of a driving-system controller and a driving-system sensor.

18. The machine of claim 17, wherein operating in the first load-priority mode includes supplying power to the first portion of the power-distribution network independent of power demands of the power loads connected to the second portion of the power-distribution network.

19. The machine of claim 18, wherein the power loads connected to the second portion of the power-distribution network include one or more components of climate-conditioning units.

20. The machine of claim 16, wherein selectively operating in the first load-priority mode or the second load-priority mode dependent upon the conditions of operation of the machine includes:

during a power deficiency, repeatedly;

operating in the first load-priority mode until the satisfaction of a first predetermined condition; and

subsequently, operating in the second load-priority mode until the satisfaction of a second predetermined condition.

21. The machine of claim 16, wherein:

the driving system is a drive train that includes a prime mover; and

operating in the first load-priority mode when the driving system is operating includes operating in the first load-priority mode when the prime mover is operating.

22. The machine of claim 16, wherein the control method includes:

when the driving system is not operating and a power deficiency exists, supplying power to the first portion and the second portion of the power-distribution network with a priority on supplying power to the second portion of the power-distribution network until a predetermined condition is met.

23. The machine of claim 16, wherein:

the electrical system includes a power converter with an adjustable output voltage;

the power converter is connected between one or more of the power sources and the first portion of the power-distribution network; and

operating in the first load-priority mode includes controlling the power converter to output power to the first portion of the power-distribution network at a substantially constant voltage.