GENERATOR SET CALIBRATION CONTROLLER

• US 20120019000A1
• Filed: 07/23/2010
• Published: 01/26/2012
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: FOLKEN, Keith Ronald, Dvorsky, Michael Allen, Meinhart, Matthew Joseph
• Granted Patent: US 8,478,550 B2
• Time in Patent Office: Days
• US Class Current: 290/7
• CPC Class Codes: H02P 9/00 Arrangements for controlling electric generators for the purpose of obtaining a desired output

Abstract

A calibration system for a generator set controller is disclosed. The calibration system may have a source of electric power, a controller in communication with the source and configured to monitor a parameter of the electric power and produce at least one output corresponding to the monitored parameter, and a power meter configured to measure the parameter of the electric power. The calibration system may also have a processor in communication with the source of electric power, the controller, and the power meter. The processor may be configured to direct electric power having a first test voltage from the source to the controller, and directly relate a value of the at least one output corresponding to the first test voltage and a value of the measured parameter to an offset error.

Claims

1. A calibration system, comprising:

a source of electric power;

a controller in communication with the source and configured to monitor a parameter of the electric power and produce at least one output corresponding to the monitored parameter;

a power meter configured to measure the parameter of the electric power; and

a processor in communication with the source of electric power, the controller, and the power meter, the processor configured to;

direct electric power having a first test voltage from the source to the controller; and

directly relate a value of the at least one output corresponding to the first test voltage and a value of the measured parameter to an offset error.

2. The calibration system of claim 1, wherein the processor is configured to program the controller with a first calibration factor that accommodates the offset error.

3. The calibration system of claim 1, wherein the first test voltage has a value of zero voltage.

4. The calibration system of claim 3, wherein the electric power is three phase power, and the processor is configured to directly relate the value of the at least one output to an offset error for each of the three phases of electric power.

5. The calibration system of claim 4, wherein the processor is further configured to:

direct electric power having a known low voltage level and a known high voltage level from the source to the controller;

make a comparison of values of the at least one output corresponding to the known low and high voltage levels to values of the measured parameter from the power meter; and

determine a scale error of the controller based on the comparison.

6. The calibration system of claim 5, wherein the processor is configured to program the controller with a second calibration factor that accommodates the scale error.

7. The calibration system of claim 5, wherein the at least one output is sinusoidal and sampled by the processor at points about midway between the known low voltage level and the known high voltage level where a slope of the at least one output is greatest, the processor being configured to relate a slope of the at least one output at the points to the scale error.

8. The calibration system of claim 7, wherein:

the known low voltage level is about 0 volts; and

the known high voltage level is about 277 volts.

9. The calibration system of claim 4, wherein:

the at least one output includes an output associated with each of the three phases of power; and

the processor is further configured to;

adjust the controller to shift the outputs corresponding with two of the three phases of power by a known amount; and

relate a difference between the two shifted outputs and a remaining non-shifted output to a time delay error.

10. The calibration system of claim 9, wherein the processor is configured to program the controller with a third calibration factor that accommodates the time delay error.

11. A method of calibrating a genset controller, comprising:

generating electric power;

monitoring the electric power at a first location;

measuring the electric power at a second location;

making a first comparison of a value of the electric power monitored at the first location with a value of the electric power measured at a second location when the electric power has desired values; and

determining a monitoring offset error based on the first comparison.

12. The method of claim 11, further including:

calculating a first calibration factor that accounts for the monitoring offset error; and

affecting future monitoring based on the first calibration factor.

13. The method of claim 11, wherein the desired values include a zero voltage value and a zero amperage value.

14. The method of claim 11, wherein the electric power is three phase alternating current, and determining the monitoring offset error includes determining the monitoring offset error for each of the three phases of electric power.

15. The method of claim 12, further including:

generating electric power having a known low voltage level and a known high voltage level;

making a second comparison of a value of the electric power monitored at the first location with a value of the electric power measured at a second location when the electric power has the low and high voltage levels; and

determining a monitoring scale error based on the second comparison.

16. The method of claim 15, further including:

calculating a second calibration factor that accounts for the monitoring scale error; and

affecting future monitoring based on the second calibration factor.

17. The method of claim 15, wherein the electric power is sinusoidal and making the second comparison includes sampling the electric power at points about midway between the known low voltage level and the known high voltage level where a slope of the electric power is greatest.

18. The method of claim 15, wherein:

the known low voltage level is about 0 volts; and

the known high voltage level is about 277 volts.

19. The method of claim 15, wherein:

the electric power is three-phase alternating current;

monitoring the electric power includes monitoring each of the three-phases; and

the method further includes;

shifting a monitoring output corresponding with two of the three phases of electric power by a known amount; and

relating a difference between the two shifted monitoring outputs and the non-shifted monitoring output to a monitoring time delay error.

20. The method of claim 19, further including:

calculating a third calibration factor that accounts for the monitoring time delay error; and

affecting future monitoring based on the third calibration factor.