Power system having transient control

• US 8,258,640 B2
• Filed: 10/30/2008
• Issued: 09/04/2012
• Est. Priority Date: 10/30/2008
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Conway, Scott Robert, Fore, Bryan Matthew
• Primary Examiner(s): Zarroli, Michael
• Application Number:
  US12/289,600
• Publication Number:
  US 20100109344A1
• Time in Patent Office: 1,405 Days
• Field of Search: 290/40.A, 290/40.B, 290/40.C, 290/1.A, 322/4, 745/72, 310/74, 701/101, 123/339
• US Class Current: 290/40.A
• CPC Class Codes: F02B 63/04 for electric generators
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 31/001 Electric control of rotation speed
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18

Abstract

A power system is disclosed. The power system may have an engine with a desired operating speed range, and a generator mechanically driven by the engine to produce electrical power directed to an external load. The power system may also have a power storage device associated with at least one of the engine and the generator, and a controller in communication with the engine and the power storage device. The controller may be configured to determine a speed of the engine deviating from the desired operating range, and to activate the power storage device to absorb or supplement at least a portion of the electrical power directed to the external load based on the determination.

Claims

1. A power system, comprising:

an engine having a desired speed range;

a generator mechanically driven by the engine to produce electrical power directed to an external load;

a power storage device associated with at least one of the engine and the generator, the power storage device being configured to;

be driven by a utility power source when the utility power source is online; and

be driven by the engine and generator when the engine and the generator are online; and

a controller in communication with the engine and the power storage device, the controller being configured to;

determine a speed of the engine deviating from the desired speed range; and

activate the power storage device to absorb or supplement at least a portion of the electrical power directed to the external load based on the determination;

the power system being configured to function as a backup power supply to the utility power source.

2. The power system of claim 1, wherein the power storage device includes a flywheel and an associated motor/generator.

3. The power system of claim 2, wherein the flywheel is continuously mechanically driven by the motor/generator to rotate at a desired speed greater than zero during normal operations of the power system, and selectively mechanically driven by the motor/generator during power absorbing operations.

4. The power system of claim 3, wherein:

the motor/generator is electrically driven by the generator during normal and power absorbing operations; and

the motor/generator is mechanically driven by the flywheel during power supplementing operations.

5. The power system of claim 3, wherein the desired speed is about 5000 rpm.

6. The power system of claim 5, wherein the flywheel speeds up when absorbing power and slows down when supplementing power.

7. The power system of claim 6, wherein a speed of the flywheel is limited within a desired range when absorbing and supplementing power.

8. The power system of claim 7, wherein the desired range of the flywheel is about 3000 rpm to about 8000 rpm.

9. A power system comprising:

an engine having a desired speed range;

a generator mechanically driven by the engine to produce electrical power directed to an external load;

a power storage device associated with at least one of the engine and the generator; and

a controller in communication with the engine and the power storage device, the controller being configured to;

determine a speed of the engine deviating from the desired speed range; and

activate the power storage device to absorb or supplement at least a portion of the electrical power directed to the external load based on the determination;

determine a change in the external load that will cause operation of the engine to deviate from the desired speed range; and

activate the power storage device to absorb or supplement at least a portion of the electrical power directed to the external load based on the determination before operation of the engine deviates from the desired speed range as a result of the change in the external load.

10. A power system, comprising:

a generator set having a desired operating range and being configured to supply electrical power to an external load;

a power storage device associated with the generator set; and

a controller in communication with the generator set and the power storage device, the controller being configured to;

determine a change in the external load; and

activate the power storage device to absorb or supplement at least a portion of the electrical power supplied to the external load when the change in the external load will cause operation of the generator set to deviate from the desired operating range;

the power system functioning as a backup power supply to a utility power source, the power storage device being driven by the utility power source when the utility power source is online and the power storage device being driven by the generator set when the generator set is online.

11. The power system of claim 10, wherein the change is a speed change of the generator set.

12. The power system of claim 10, wherein the change is a change in a characteristic of electrical power produced by the generator set.

13. A method of operating a generator set, comprising:

combusting a mixture of fuel and air to generate electrical power;

directing the electrical power to an external load;

determining an engine speed of the generator set, the generator set functioning as a backup power supply to a utility power source;

comparing the engine speed to a desired engine speed;

absorbing or supplementing at least a portion of the electrical power directed to the external load based on the comparison;

determining an interruption in the power supplied from the utility power source to the external load when the generator set is offline; and

supplementing the electrical power directed to the external load until the generator set is online.

14. The method of claim 13, wherein absorbing includes converting electrical power into stored mechanical rotational power, and supplementing includes converting stored mechanical rotational power into electrical power.

15. The method of claim 14, further including continuously converting electrical power into stored mechanical rotational power during normal operations of the generator set.

16. The method of claim 13, further including:

storing power from the utility power source when the utility power source is online; and

storing power from the generator set when the generator set is online,

wherein the supplemental electrical power directed to the external load is stored power.