DC plant controller and method for selecting among multiple power sources

• US 9,722,421 B2
• Filed: 05/01/2012
• Issued: 08/01/2017
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Acleap Power Incorporated
• Original Assignee: General Electric Company
• Inventors: Jagota, Anurag, Davis, Roy J., Thottuvelil, Vijayan J.
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Parries, Dru
• Application Number:
  US13/461,172
• Publication Number:
  US 20120217810A1
• Time in Patent Office: 1,918 Days
• Field of Search: 307 65
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources

Abstract

Various embodiments of a DC plant controller and methods of selecting among multiple power sources. In one embodiment, the DC plant controller includes: (1) a source identifier configured to identify power sources couplable to a common DC bus, (2) a source prioritizer coupled to the source identifier and configured to prioritize the power sources based on at least one criterion, (3) an output characteristic assigner coupled to the source prioritizer and configured to place ones of the power sources on standby based on a calculated battery holdup time.

Claims

1. A DC plant controller, comprising:

a non-transitory memory configured to store power source data indicative of types of power sources;

a source identifier configured to gain access to the power source data in said non-transitory memory to identify power sources couplable to a common DC bus;

a source prioritizer coupled to said source identifier and configured to prioritize said power sources based on the power source data received from said source identifier, said power sources including a high priority power source and a low priority power source; and

an output characteristic assigner coupled to said source prioritizer and configured to assign respective output characteristics, including an output voltage, a current limit, and a current share value, to said power sources that differ from one another as a function of said priority,

wherein said output characteristic assigner is further configured to assign respective output voltages to said power sources based on said priority, wherein said high priority power source is assigned a higher output voltage than said low priority power source,

wherein said output characteristic assigner is further configured to assign respective current limits to said power sources based on said priority, wherein said high priority power source is assigned a larger percentage current limit than said low priority power source, wherein the respective current limits are defined relative to respective current capacities,

wherein said output characteristic assigner is further configured to assign respective current share values to said power sources based on said priority and a total voltage and current output to said common DC bus, wherein said high priority power source is assigned a larger percentage current share value than said low priority power source, wherein percentage current share values are defined relative to respective load capacities, and

wherein said output characteristic assigner is further configured to adjust the respective output voltages and the respective current limits of said power sources based on the respective current share values.

2. The DC plant controller as recited in claim 1 wherein the respective output voltages differ by less than one volt and decrease as said priority decreases.

3. The DC plant controller as recited in claim 1 wherein the respective output voltages differ by less than five volts and decrease as said priority decreases.

4. The DC plant controller as recited in claim 1 wherein the respective output voltages differ by less than ten volts and decrease linearly as said priority decreases.

5. The DC plant controller as recited in claim 1 wherein said power sources are selected from the group consisting of:

an engine-driven generator,

a windmill-driven generator,

a solar array, and

AC mains.

6. The DC plant controller as recited in claim 1 wherein said source prioritizer is further configured to prioritize said power sources based on at least one criterion selected from the group consisting of:

operational cost,

carbon footprint,

noise generation,

types of said power sources, and

an environmental factor.

7. The DC plant controller as recited in claim 1 wherein each of said power sources is associated with at least one of a DC-DC converter and a rectifier, and said output characteristic assigner is further configured to assign the respective voltage limits, the respective current limits, and the respective current share values to said rectifiers and said DC-DC converters.

8. The DC plant controller as recited in claim 7 wherein said source identifier is configured to communicate with said power sources via a first bidirectional link and said output characteristic assigner is configured to communicate with said power sources via a second bidirectional link.

9. The DC plant controller as recited in claim 1, further comprising a history database configured to store historical data regarding the past operation of a DC plant controlled by said DC plant controller.

10. A method of selecting among multiple power sources couplable to a common DC bus, comprising:

identifying power sources couplable to the common DC bus based on power source data stored in a non-transitory memory;

prioritizing the power sources based on at least historical data for the power sources and the power source data retrieved from the non-transitory memory, the power sources including a high priority power source and a low priority power source;

assigning output characteristics to the power sources that differ from one another as a function of the priority, including;

assigning respective output voltages to the power sources based on their respective priority, wherein the high priority power source is assigned a higher output voltage than the low priority power source,

assigning respective current limits to the power sources based on their respective priority, wherein the high priority power source is assigned a larger percentage current limit than the low priority power source, wherein the respective current limits are defined relative to respective current capacities of the power sources,

assigning respective current share values to the power sources based on their respective priority and a total voltage and current output to the common DC bus, wherein the high priority power source is assigned a larger percentage current share value than the low priority power source, wherein percentage current share values are defined relative to respective load capacities, and

adjusting respective output voltages and the respective current limits of the power sources based on the respective current share values.

11. The method as recited in claim 10, wherein the respective output voltages differ by less than one volt and decrease as the priority decreases.

12. The method as recited in claim 10, wherein the respective output voltages differ by less than five volts and decrease as the priority decreases.

13. The method as recited in claim 10, wherein the respective output voltages differ by less than ten volts and decrease linearly as said priority decreases.

14. The method as recited in claim 10, wherein the power sources are selected from the group consisting of:

an engine-driven generator,

a windmill-driven generator,

a solar array, and

AC mains.

15. The method as recited in claim 10 wherein prioritizing the power sources further comprises prioritizing based on at least one criterion selected from the group consisting of:

operational cost,

carbon footprint,

noise generation,

types of said power sources, and

an environmental factor.

16. The method as recited in claim 10 wherein rectifiers and DC-DC converters are associated with the power sources and said method further comprises assigning power limits to at least one of the rectifiers and DC-DC converters.

17. The method as recited in claim 16 further comprising communicating identities from the power sources to a source identifier via a first bidirectional link and communicating output characteristic and power limit commands from an output characteristic assigner to the power sources, the rectifiers and DC-DC converters via a second bidirectional link.

18. The method as recited in claim 10, further comprising storing history data regarding past operation of the power sources.

19. A DC plant controller, comprising:

a non-transitory memory configured to store power source data indicative of types of power sources;

a source identifier configured to gain access to the power source data in said non-transitory memory to identify power sources couplable to a common DC bus;

a source prioritizer coupled to said source identifier and configured to prioritize said power sources based on historical data for the power sources and the power source data received from said source identifier, wherein said power sources include a high priority power source and a low priority power source; and

an output characteristic assigner coupled to said source prioritizer, wherein said output characteristic assigner is configured to;

assign respective output voltages to said power sources based on their respective priority, wherein said high priority power source is assigned a higher output voltage than said low priority power source,

assign respective current limits to said power sources based on their respective priority, wherein said high priority power source is assigned a larger percentage current limit than said low priority power source, wherein the respective current limits are defined relative to respective current capacities of said power sources,

assign respective current share values to said power sources based on their respective priority and a total voltage and current output to said common DC bus, wherein said high priority power source is assigned a larger percentage current share value than said low priority power source, wherein percentage current share values are defined relative to respective load capacities, and

adjust respective output voltages and the respective current limits of said power sources based on the respective current share values.

20. The DC plant controller as recited in claim 19, further comprising a history database configured to store the historical data regarding the past operation of a DC plant controlled by said DC plant controller.