Delayed reactive electrical consumption mitigation

• US 9,048,671 B2
• Filed: 02/24/2012
• Issued: 06/02/2015
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Engie Storage Services NA LLC (ENGIE SA)
• Original Assignee: Green Charge Networks LLC (ENGIE SA)
• Inventors: Prosser, Ronald D.
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): OMAR, AHMED H
• Application Number:
  US13/405,187
• Publication Number:
  US 20130221929A1
• Time in Patent Office: 1,194 Days
• Field of Search: 320/135
• US Class Current: 1/1
• CPC Class Codes: G01R 21/00 Arrangements for measuring electric power or power factor G01R7/12 takes precedence
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

The electrical consumption mitigation provided by energy storage systems can be unreliable when a consumption peak lasts long enough to deplete the energy stored and the remainder of the peak is unmitigated. By implementing a waiting period between detecting the peak and discharging the energy storage in which characteristics of the peak are observed, a peak mitigation system can lengthen the effective discharge duration of the energy storage system and prevent unmitigated plateaus from appearing. For example, when a consumption plateau is detected, the system may discharge at a slower rate than when a spike is detected in order to prolong mitigation activities before the conclusion of the plateau. Thus otherwise-incurred demand-related utility charges can be reduced without having to increase the capacity of the mitigation system. In some cases, these processes are performed with respect to the bounds of demand-averaged time periods used to calculate demand charges.

Claims

1. A method of controlling the discharge of an energy storage system (ESS) for electricity consumption mitigation, the ESS being connected to an electrical system at a site, the method comprising:

detecting a peak in electricity consumption of an electrical system at the site;

responsive to detecting the peak, preventing the ESS from discharging for purposes of mitigating the consumption of the peak from when the peak is detected until a waiting period has elapsed;

measuring an electricity consumption indicating parameter of electrical system during the waiting period; and

discharging energy from the ESS to the electrical system after the waiting period has elapsed according to discharge instructions, the discharge instructions comprising a magnitude function providing the magnitude of the power level at which to discharge the ESS, wherein the magnitude function is dependent on the electricity consumption indicating parameter measured.

2. The method of claim 1, said discharge instructions further comprising a duration function providing the length of time to discharge the ESS.

3. The method of claim 2, wherein said ESS has a state of charge, and said duration function is dependent on the state of charge.

4. The method of claim 1, wherein said magnitude function provides a reduced magnitude of the power level at which to discharge the ESS for purposes of mitigating the consumption of the peak when the peak is detected as a plateau.

5. The method of claim 4, wherein the peak is detected as a plateau if the electricity consumption indicating parameter measured at the end of the waiting period exceeds a peak triggering threshold level.

6. The method of claim 4, wherein the peak is detected as a plateau if the average electricity consumption indicating parameter measured during at least a portion the waiting period exceeds a peak triggering threshold level.

7. The method of claim 1, wherein said discharge instructions provide that discharging ends when the electricity consumption of the electrical system at the site drops below a consumption threshold value.

8. The method of claim 1, wherein said waiting period is reduced if the peak is detected during a demand-averaged period, wherein the waiting period is reduced in such a manner as to allow the waiting period to elapse and the discharging of the ESS to finish before the demand-averaged period concludes.

9. The method of claim 1, wherein said peak is detected during a demand-averaged period that is within a billing cycle, and the ESS is discharged for purposes of mitigation of the consumption of the peak only if the resulting demand average for the demand-averaged period after discharging will not exceed a maximum demand average that occurred in a preceding demand-averaged period in the billing cycle.

10. The method of claim 1, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to time elapsed while discharging.

11. The method of claim 1, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to a value representing the electricity consumption of the electrical system at the site in the waiting period.

12. The method of claim 1, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to the electricity consumption of the electrical system at the site while the ESS is discharged.

13. The method of claim 12, wherein the reduction in magnitude of the power level during discharging is less than or equal to a reduction limit.

14. The method of claim 1, wherein the ESS is discharged for purposes of mitigating the consumption of a load when the peak is detected without a waiting period or after a shortened waiting period when predetermined conditions are met, the conditions including at least one of:

(1) the peak being detected during a predetermined time period, (2) a predetermined electrical system at the site being activated, and (3) an electricity consumption indicating parameter of an electrical system at the site exceeding a predetermined value.

15. A tangible computer-readable medium including computer-executable instructions stored thereon for performing a method for controlling the discharge of an energy storage system (ESS) for electricity consumption mitigation, the ESS being connected to an electrical distribution grid at a site, the method comprising:

detecting a peak in electricity consumption of an electrical system at the site;

responsive to detecting the peak, preventing the ESS from discharging for purposes of mitigating the consumption of the peak from when the peak is detected until a waiting period has elapsed;

measuring an electricity consumption indicating parameter of electrical system during the waiting period; and

discharging energy from the ESS to the electrical system after the waiting period has elapsed according to discharge instructions, the discharge instructions comprising a magnitude function providing the magnitude of the power level at which to discharge the ESS, wherein the magnitude function is dependent on the electricity consumption indicating parameter measured.

16. The tangible computer-readable medium of claim 15, said discharge instructions further comprising a duration function providing the length of time to discharge the ESS.

17. The tangible computer-readable medium of claim 15, wherein said ESS has a state of charge, and said duration function is dependent on the state of charge.

18. The tangible computer-readable medium of claim 15, wherein said magnitude function provides a reduced magnitude of the power level at which to discharge the ESS for purposes of mitigating the consumption of the peak when the peak is detected as a plateau.

19. The tangible computer-readable medium of claim 15, wherein said peak is detected during a demand-averaged period that is within a billing cycle, and the ESS is discharged for purposes of mitigation of the consumption of the peak only if the resulting demand average for the demand-averaged period after discharging will not exceed a maximum demand average that occurred in a preceding demand-averaged period in the billing cycle.

20. The tangible computer-readable medium of claim 15, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to time elapsed while discharging.

21. The tangible computer-readable medium of claim 15, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to a value representing the electricity consumption of the site in the waiting period.

22. The tangible computer-readable medium of claim 15, wherein said magnitude function provides a reduction in magnitude of the power level while discharging the ESS, the reduction in magnitude being inversely proportional to the electricity consumption of the site while the ESS is discharged.

23. The tangible computer-readable medium of claim 15, wherein the ESS is discharged for purposes of mitigating the consumption of a load when the peak is detected without a waiting period or after a shortened waiting period when predetermined conditions are met, the conditions including at least one of:

(1) the peak being detected during a predetermined time period, (2) a predetermined electrical system at the site being activated, and (3) an electricity consumption indicating parameter of an electrical system at the site exceeding a predetermined value.

24. An apparatus for controlling the discharge of an energy storage system (ESS) for electricity consumption mitigation, the ESS being connected to an electrical distribution grid at a site, the apparatus comprising:

a. a processor; and

b. a memory storing instructions executable by the processor to perform processes that include;

i. detecting a peak in electricity consumption of the site;

ii. responsive to detecting the peak, preventing the ESS from discharging for purposes of mitigating the consumption of the peak, the preventing lasting from when the peak is detected until a waiting period has elapsed;

iii. measuring the electricity consumption of the site during the waiting period; and

iv. discharging the ESS into the site after the waiting period has elapsed according to discharge instructions, the discharge instructions comprising a magnitude function providing the magnitude of the power level at which to discharge the ESS, wherein the magnitude function is dependent on the electricity consumption of the site measured during the waiting period.

25. The apparatus of claim 24, said discharge instructions further comprising a duration function providing the length of time to discharge the ESS.

26. The apparatus of claim 24, wherein said magnitude function provides a reduced magnitude of ESS discharging when the peak is a plateau.