Power system with multiple generator units

• US 7,952,306 B2
• Filed: 06/01/2007
• Issued: 05/31/2011
• Est. Priority Date: 06/01/2007
• Status: Active Grant

• Current Assignee: Progress Rail Services Corporation (Caterpillar Incorporated)
• Original Assignee: Progress Rail Services Corporation (Caterpillar Incorporated)
• Inventors: Fonseca, Roy Christopher, Wright, Jeffrey Holt
• Primary Examiner(s): Masih; Karen
• Application Number:
  US11/806,613
• Publication Number:
  US 20080297075A1
• Time in Patent Office: 1,460 Days
• Field of Search: 318/146, 318/108, 318/52, 318/375, 322/29, 475/5, 180/65.2, 361/699, 290/6
• US Class Current: 318/146
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2220/18 Reluctance machines
• CPC Class Codes: B60L 50/10 using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines
• 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

Abstract

A method of operating a power system is provided. The method may include running one or more of a plurality of generator units that each include a power source, a first electric generator, and a second electric generator. Additionally, the method may include supplying electricity from one or more of the first electric generators of the one or more running generator units to a first set of one or more electric power loads. The method may also include supplying electricity from one or more of the second electric generators of the one or more running generator units to a second set of one or more electric power loads.

Claims

1. A method of operating a power system, comprising:

running one or more of a plurality of generator units that each include a power source, a first electric generator, and a second electric generator;

supplying electricity from one or more of the first electric generators of the one or more running generator units to a first set of one or more electric power loads;

supplying electricity from one or more of the second electric generators of the one or more running generator units to a second set of one or more electric power loads

wherein the power system is part of a mobile machine,

wherein supplying electricity to the first set of one or more electric power loads includes supplying electricity to one or more electric propulsion motors to propel the mobile machine; and

wherein supplying electricity to the one or more electric propulsion motors to propel the mobile machine includes allowing the voltage of the electricity supplied to the one or more electric propulsion motors to vary dependent on the speed of the electric propulsion motors.

2. The method of claim 1, wherein supplying electricity to the first set of one or more electric power loads and supplying electricity to the second set of one or more electric power loads includes, in at least some circumstances, supplying to the first set of electric power loads electricity that has at least one characteristic different from electricity supplied to the second set of electric power loads.

3. The method of claim 1, wherein supplying electricity to the second set of one or more electric power loads includes regulating the voltage of the electricity supplied to the second set of one or more electric power loads.

4. The method of claim 1, wherein running one or more of the plurality of generator units includes

using a first quantity of electric current that is associated with the first set of one or more electric power loads as a factor in controlling which of the plurality of generator units run;

and

using a second quantity of electric current that is associated with the second set of one or more electric power loads as a factor separate from the first quantity of electric current in controlling which of the plurality of generator units run.

5. The method of claim 4, wherein running one or more of the plurality of generator units further includes using a quantity of electric power as a factor separate from the first quantity of electric current and the second quantity of electric current in controlling which of the generator units run, the quantity of electric power being associated with a set of electric power loads that includes the first set of one or more electric power loads and the second set of one or more electric power loads.

6. A method of operating a power system, the method comprising:

controlling which of a plurality of generator units of the power system run, including

using at least one power quantity as a factor in controlling which of the generator units run, and

using at least one electric current quantity as a factor separate from the at least one power quantity in controlling which of the generator units run.

7. The method of claim 6, wherein using at least one electric current quantity as a factor separate from the at least one power quantity in controlling which of the generator units run includes using a quantity of electric current associated with a first set of one or more electric power loads as a factor in controlling which of the generator units run in order to provide sufficient generating capacity to meet an electric current requirement of the first set of one or more electric power loads.

8. The method of claim 7, wherein using at least one power quantity as a factor in controlling which of the generator units run includes using a quantity of power required by one or more electric power loads to control which of the generator units run in order to provide sufficient generating capacity to meet the required quantity of power.

9. The method of claim 7, wherein controlling which of the plurality of generator units run further includes using a second quantity of electric current that is associated with a second set of one or more electric power loads as a factor separate from the first quantity of electric current in controlling which of the generator units run in order to provide sufficient generating capacity to meet an electric current requirement of the second set of one or more electric power loads.

10. The method of claim 9, wherein using at least one power quantity as a factor in controlling which of the generator units run includes using a quantity of power associated with a third set of electric power loads as a factor in controlling which of the generator units run in order to provide sufficient generating capacity to meet a power requirement of the third set of electric power loads, the third set of electric power loads including the first set of one or more electric power loads and the second set of one or more electric power loads.

11. The method of claim 9, wherein:

the power system is part of a mobile machine;

the first set of one or more electric power loads includes one or more electric propulsion motors;

the method further includes propelling the mobile machine at least in part by operating one or more of the one or more electric propulsion motors with electricity from one or more of the plurality of generator units; and

the second set of one or more electric power loads is electrically isolated from the first set of one or more electric power loads.

12. The method of claim 6, wherein using at least one electric current quantity as a factor separate from the at least one power quantity in controlling which of the generator units run includes, when one or more of the generator units are running, starting one or more additional generator units when a quantity of electric current required by a set of one or more electric power loads approaches a capacity of the one or more running generator units to supply electric current to the set of one or more electric power loads.

13. A mobile machine, comprising:

a first set of one or more electric power loads, including one or more electric propulsion motors for propelling the mobile machine;

a second set of one or more electric power loads that is electrically isolated from the first set of one or more electric power loads;

a plurality of generator units that each includes

a power source,

a first electric generator for supplying electricity to the first set of one or more electric power loads, and

a second electric generator for supplying electricity to the second set of one or more electric power loads; and

power-system controls that control one or more aspects of the supply of electricity from the plurality of generator units to the second set of one or more electric power loads, including, when one or more of the second electric generators are supplying electricity to the second set of electric power loads, regulating the voltage of the electricity supplied from the one or more second electric generators to the second set of one or more electric power loads.

14. The mobile machine of claim 13, wherein when one or more of the first electric generators are supplying electricity to the first set of one or more electric power loads, the power-system controls allow voltage of the electricity supplied by the one or more first electric generators to the first set of one or more electric power loads to vary dependent on the speed of the one or more electric propulsion motors.

15. The mobile machine of claim 13, further including power-system controls that control which of the plurality of generator units run, including

using a quantity of electric power associated with one or more electric power loads as a factor in controlling which of the generator units run;

and

using quantity of electric current associated with one or more electric power loads as a factor separate from the quantity of electric power in controlling which of the generator units run.

16. A mobile machine, comprising:

a first set of one or more electric power loads, including one or more electric propulsion motors for propelling the mobile machine;

a second set of one or more electric power loads that is electrically isolated from the first set of one or more electric power loads;

a plurality of generator units that each includes

a power source,

a first electric generator for supplying electricity to the first set of one or more electric power loads, and

a second electric generator for supplying electricity to the second set of one or more electric power loads; and

power-system controls that control which of the plurality of generator units run, including

using a first quantity of electricity that is associated with the first set of one or more electric power loads as a factor in controlling which of the plurality of generator units run; and

using a second quantity of electricity that is associated with the second set of one or more electric power loads as a factor separate from the first quantity of electricity in controlling which of the plurality of generator units run.

17. The mobile machine of claim 16, wherein controlling which of the plurality of generator units run further includes using a quantity of power associated with one or more electric power loads of the mobile machine as a factor separate from the first quantity of electric current and the second quantity of electric current in controlling which of the plurality of generator units run.