Systems and Methods for Integrating Demand Response with Service Restoration in an Electric Distribution System

• US 20130085624A1
• Filed: 08/27/2012
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited
• Original Assignee: ABB Research Ltd. (ABB Ltd.)
• Inventors: Yang, Fang, Mohagheghi, Salman, Li, Zhao
• Granted Patent: US 10,298,013 B2
• Time in Patent Office: Days
• US Class Current: 700/297
• CPC Class Codes: H02J 2310/54 according to a pre-established time schedule
• CPC Class Codes: H02J 3/144 Demand-response operation of the power transmission or distribution network
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

Systems and methods for integrating demand response with service restoration in an electric distribution system. The electric distribution system may include a plurality of regions, zones, and/or areas including at least an outage area that includes a fault and is not receiving electric current from the electric distribution system and a restoration area that is receiving electric current from the electric distribution system and that may be selectively configured to provide electric current to a selected portion of the outage area. The electric distribution system also includes a plurality of demand responsive loads configured to be selectively isolated from the electric distribution system responsive to a load shed signal. The demand responsive loads may be selectively utilized during service restoration, such as to provide additional excess capacity within the restoration area and/or decrease a magnitude of the electric load applied by the selected portion of the outage area.

Claims

1. A method of restoring electrical service to a selected portion of an electric distribution system, wherein the selected portion includes at least a sub-portion of an outage area, wherein the outage area includes a fault and is not receiving an electric current from the electric distribution system, and further wherein the electric distribution system is in electrical communication with a plurality of demand responsive loads configured to be selectively isolated from the electric distribution system responsive to a load shed signal, the method comprising:

identifying a restoration area, wherein the restoration area includes a portion of the electric distribution system that is receiving the electric current from the electric distribution system and is selectively configured to provide the electric current to the selected portion of the electric distribution system;

determining an expected fault reparation time;

forecasting an estimated electrical load within the selected portion of the electric distribution system during the expected fault reparation time;

evaluating the plurality of demand responsive loads;

selecting an isolated portion of the plurality of demand responsive loads to be isolated from the electric distribution system during at least a portion of the expected fault reparation time;

sending the load shed signal to the isolated portion of the plurality of demand responsive loads; and

providing the electric current from the restoration area to the selected portion of the electric distribution system.

2. The method of claim 1, wherein the evaluating includes estimating a magnitude of an electrical load applied by each of the demand responsive loads that comprise the plurality of demand responsive loads, and further wherein the identifying includes estimating an excess capacity of the restoration area.

3. The method of claim 2, wherein the method further includes comparing the excess capacity to the estimated electrical load.

4. The method of claim 3, wherein the selecting includes selecting the isolated portion of the plurality of demand responsive loads such that the estimated electrical load is less than the excess capacity.

5. The method of claim 3, wherein the method further includes repeating the determining, forecasting, and comparing to ensure that the excess capacity is greater than the estimated electrical load prior to performing the providing.

6. The method of claim 5, wherein the method further includes repeating the evaluating, selecting, and sending responsive to determining at least one of that the excess capacity is less than the estimated electrical load and that the excess capacity is within a threshold amount of the estimated electrical load.

7. A method of restoring electrical service to a selected portion of an electric distribution system, the method comprising:

forecasting an estimated electrical load within the selected portion of the electric distribution system during an expected fault reparation time;

estimating an excess capacity of a restoration area;

comparing the excess capacity to the estimated electrical load;

evaluating a plurality of demand responsive loads, wherein the plurality of demand responsive loads is configured to be selectively isolated from the electric distribution system responsive to a load shed signal;

selecting an isolated portion of the plurality of demand responsive loads to be isolated from the electric distribution system during at least a portion of the expected fault reparation time, wherein the selecting is based at least in part on at least one of the comparing and the evaluating;

sending the load shed signal to the isolated portion of the plurality of demand responsive loads; and

providing an electric current from the restoration area to the selected portion of the electric distribution system.

8. The method of claim 7, wherein the method further includes identifying the restoration area, wherein the restoration area includes a portion of the electric distribution system that is receiving the electric current from the electric distribution system, and further wherein the restoration area is selectively configured to provide the electric current to the selected portion of the electric distribution system.

9. The method of claim 7, wherein the method further includes determining the expected fault reparation time.

10. The method of claim 7, wherein the method further includes repeating the forecasting, estimating, and comparing to ensure that the excess capacity is greater than the estimated electrical load prior to performing the providing.

11. The method of claim 10, wherein the method further includes repeating the evaluating, selecting, and sending responsive to determining at least one of that the excess capacity is less than the estimated electrical load and that the excess capacity is within a threshold amount of the estimated electrical load.

12. The method of claim 7, wherein the forecasting includes estimating an expected electrical load within the selected portion of the power distribution system during the expected fault reparation time, and further wherein the estimating includes estimating at least one of an expected load vs. time correlation during the expected fault reparation time and a maximum expected load during the expected fault reparation time.

13. The method of claim 7, wherein estimating the excess capacity of the restoration area includes at least one of evaluating a maximum electrical load that may be supplied by the restoration area, evaluating a magnitude of an electrical load that is being supplied by the restoration area, comparing the maximum electrical load that may be supplied by the restoration area to the magnitude of the electrical load that is being supplied by the restoration area, evaluating a distance between the restoration area and the selected portion of the electric distribution system, and evaluating a maximum capacity of an electrical conduit that is selectively configured to provide electrical communication between the restoration area and the selected portion of the electric distribution system.

14. The method of claim 7, wherein the selecting includes selecting the isolated portion of the plurality of demand responsive loads such that, after the isolated portion of the plurality of demand responsive loads have been isolated from the electric distribution system, the excess capacity will be greater than the estimated electrical load.

15. The method of claim 7, wherein the isolated portion of the plurality of demand responsive loads includes a restoration area demand responsive load that is within the restoration area, wherein the method includes isolating the restoration area demand responsive load from the restoration area, and further wherein the isolating includes increasing the excess capacity of the restoration area.

16. The method of claim 7, wherein the isolated portion of the plurality of demand responsive loads includes a selected portion demand responsive load that is within the selected portion of the electric distribution system, wherein the method includes isolating the selected portion demand responsive load from the selected portion of the electric distribution system, and further wherein the isolating includes decreasing the estimated electrical load.

17. The method of claim 7, wherein sending the load shed signal includes isolating the isolated portion of the plurality of demand responsive loads from the electric distribution system.

18. The method of claim 17, wherein the isolating includes automatically isolating at least a sub-portion of the isolated portion of the plurality of demand responsive loads from the electric distribution system directly responsive to receipt of the load shed signal.

19. The method of claim 17, wherein the sending includes requesting that at least a requested portion of the isolated portion of the plurality of demand responsive loads be isolated from the electric distribution system, and further wherein the isolating includes manually isolating at least a fraction of the requested portion.

20. The method of claim 17, wherein the isolating includes waiting for a notification time interval after the sending and prior to the isolating.

21. The method of claim 7, wherein the method further includes receiving an acknowledgement signal indicating that at least one of the isolated portion of the plurality of demand responsive loads has been isolated from the electric distribution system.

22. The method of claim 7, wherein providing the electric current includes establishing electrical communication between the selected portion of the electric distribution system and the restoration area.

23. The method of claim 7, wherein the selected portion of the electric distribution system includes at least a sub-portion of an outage area, wherein the outage area includes a fault, wherein the outage area is not receiving the electric current from the electric distribution system, wherein the method includes detecting and isolating the fault, wherein the isolating includes ceasing electrical communication between the fault and a portion of the electric distribution system that is upstream from the fault, and further wherein the isolating includes ceasing electrical communication between the fault and a portion of the electric distribution system that is downstream from the fault.

24. The method of claim 7, wherein the method further includes repeating the method, wherein the repeating is performed responsive at least in part to at least one of expiration of a threshold time interval, expiration of a maximum load shed time for at least one of the isolated portion of the plurality of demand responsive loads, a change in a status of the restoration area, a change in a status of the selected portion of the electric distribution system, a change in the estimated electrical load, a change in the expected fault reparation time, and a change in a status of at least one demand responsive load associated with at least one of the restoration area and the selected portion of the electric distribution system.

25. The method of claim 7 embodied as a plurality of executable instructions that are stored on a storage medium and that, when executed, implement a computer-executable method according to claim 7.

26. A system for restoring electrical service to a selected portion of an electric distribution system, the system comprising:

a controller configured to perform the method of claim 7.