PERFORMING PASSIVE MAINTENANCE ON AN ENERGY STORAGE FARM

• US 20160226287A1
• Filed: 01/30/2015
• Published: 08/04/2016
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Djan-Sampson, Patrick Osae, Cutright, Richard Hayes, Kaucic, Robert August, Webb, Joshua Paul
• Granted Patent: US 10,126,723 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 19/041 Function-oriented details
• CPC Class Codes: H02J 3/32 using batteries with converting means

Abstract

In one aspect, a method of performing a passive maintenance operation on an energy storage farm may generally include receiving data associated with a maintenance schedule for each energy storage system in the plurality of energy storage systems, identifying at least one energy storage system as a charge contributor based at least in part on the data associated with the maintenance schedule, identifying at least one energy storage system as a discharge contributor based at least in part on the data associated with the maintenance schedule, and controlling the operation of the energy storage farm such that power distribution in the energy storage farm is biased so as to increase the state of charge of the charge contributor(s) prior to increasing the state of charge of the discharge contributor(s).

Claims

1. A method for distributing power among a plurality of energy storage systems in an energy storage farm, each energy storage system of the plurality of energy storage systems having at least one energy storage device, the method comprising:

receiving data associated with a maintenance schedule for each energy storage system in the plurality of energy storage systems, the maintenance schedule associated at least in part with a maintenance operation for increasing a state of charge of each energy storage system to a top-of-charge state;

identifying at least one energy storage system as a charge contributor based at least in part on the data associated with the maintenance schedule;

identifying at least one energy storage system as a discharge contributor based at least in part on the data associated with the maintenance schedule; and

controlling the operation of the energy storage farm such that power distribution in the energy storage farm is biased so as to increase the state of charge of the charge contributor prior to increasing the state of charge of the discharge contributor.

2. The method of claim 1, wherein the data corresponds to data derived from a countdown timer associated with each energy storage system, the data derived from the countdown timer being indicative of the amount of time remaining until the energy storage system is to be taken offline to allow the state of charge of such energy storage system to be increased to its top-of-charge state.

3. The method of claim 2, wherein identifying the at least one energy storage system as a charge contributor comprises:

monitoring the countdown timer for each energy storage system;

determining whether a countdown timer value for any of the energy storage systems of the plurality of energy storage systems is less than a maintenance threshold; and

if the countdown timer value of a first energy storage system is less than the maintenance threshold, identifying the first energy storage system as the contributor.

4. The energy storage system of claim 3, wherein identifying the first energy storage system as the charge contributor comprises:

initially identifying the first energy storage system as a candidate charge contributor when it is determined that the countdown timer value for the first energy storage system is less than the maintenance threshold;

determining whether a total amount of charge contributors for the energy storage farm is less than a charge contributor threshold; and

if the amount of charge contributors is less than the charge contributor threshold, identifying the first energy storage system as the charge contributor.

5. The method of claim 3, further comprising identifying each energy storage system of the plurality of energy storage systems that is not identified as a charge contributor as a discharge contributor.

6. The method of claim 1, wherein the power distribution within the energy storage farm is configured to be biased so as to drive the state of charge of the charge contributor to the top-of-charge state prior to increasing the state of charge of the discharge contributor.

7. The method of claim 1, further comprising:

receiving a power request associated with a power output to be discharged from the energy storage farm; and

controlling the operation of the energy storage farm such that power is discharged first from the discharge contributor in order to satisfy the power request.

8. The method of claim 7, further comprising:

determining if the power request exceeds a cumulative power capability of all of the discharge contributors within the energy storage farm; and

if the power request exceeds the cumulative power capability, controlling the operation of the energy storage farm such that power is also discharged from the charge contributor in order to satisfy the power request.

15. The energy storage farm of claim 1, wherein the one or more operations further comprise:

receiving a power request associated with a power output to be discharged from the energy storage farm; and

controlling the operation of the energy storage farm such that power is discharged first from the discharge contributor in order to satisfy the power request.

16. The energy storage farm of claim 15, further comprising:

determining if the power request exceeds a cumulative power capability of all of the discharge contributors within the energy storage farm; and

if the power request exceeds the cumulative power capability, controlling the operation of the energy storage farm such that power is also discharged from the at least one charge contributor in order to satisfy the power request.

9. An energy storage farm, comprising:

a plurality of energy storage systems, each energy storage system having at least one energy storage device; and

a control system configured to perform one or more operations, the one or more operations comprising;

receiving data associated with a maintenance schedule for each energy storage system in the plurality of energy storage systems, the maintenance schedule associated at least in part with a maintenance operation for increasing a state of charge of each energy storage system to a top-of-charge state;

identifying at least one energy storage system as a charge contributor based at least in part on the data associated with the maintenance schedule;

identifying at least one energy storage system as a discharge contributor based at least in part on the data associated with the maintenance schedule; and

controlling the operation of the energy storage farm such that power distribution in the energy storage farm is biased so as to increase the state of charge of the charge contributor prior to increasing the state of charge of the discharge contributor.

10. The energy storage farm of claim 9, wherein the data corresponds to data derived from a countdown timer associated with each energy storage system, the data derived from the countdown timer being indicative of the amount of time remaining until the energy storage system is to be taken offline to allow the state of charge of such energy storage system to be increased to its top-of-charge state.

11. The energy storage farm of claim 10, wherein identifying the at least one energy storage system as a charge contributor comprises:

monitoring the countdown timer for each energy storage system;

determining whether a countdown timer value for any of the energy storage systems of the plurality of energy storage systems is less than a maintenance threshold; and

if the countdown timer value of a first energy storage system is less than the maintenance threshold, identifying the first energy storage system as the charge contributor.

12. The energy storage farm of claim 11, wherein identifying the first energy storage system as the charge contributor comprises:

initially identifying the first energy storage system as a candidate charge contributor when it is determined that the countdown timer value for the first energy storage system is less than the maintenance threshold;

determining whether a total amount of charge contributors for the energy storage farm is less than a charge contributor threshold; and

if the amount of charge contributors is less than the charge contributor threshold, identifying the first energy storage system as the charge contributor.

13. The energy storage farm of claim 11, further comprising identifying each energy storage system of the plurality of energy storage systems that is not identified as a charge contributor as a discharge contributor.

14. The energy storage farm of claim 9, wherein the control system is configured to bias the power distribution in the energy storage farm so as to drive the state of charge of the at least one charge contributor to the top-of-charge state prior to increasing the state of charge of the at least one discharge contributor.

17. A method for distributing power among a plurality of energy storage systems in an energy storage farm, each energy storage system of the plurality of energy storage systems having at least one energy storage device, the method comprising:

identifying at least one energy storage system as a charge contributor and at least one energy storage system as a discharge contributor based at least in part on data indicative of a maintenance schedule, the maintenance schedule associated at least in part with a maintenance operation for increasing a state of charge of each energy storage system to a top-of-charge state;

receiving a power distribution input associated with an amount of power to be delivered from or received by the energy storage farm;

responsive to the power distribution input, determining an initial power value for each energy storage system in the energy storage farm based at least in part on a state of charge associated with the energy storage system;

determining an unallocated power value based at least in part on the received power distribution input and the initial power values determined for each energy storage system;

determining an updated power value for each energy storage system based at least in part on the unallocated power value, the updated power value for at least one energy storage system within the energy storage farm corresponding to an increase in the initial power value determined for the at least one energy storage system; and

controlling the operation of the energy storage farm such that each energy storage system delivers or receives an amount of power equal to the updated power value determined for the energy storage system.

18. The method of claim 17, wherein the power distribution input corresponds to a power request associated with discharging power from the energy storage farm, further comprising, when the sum of the updated power values for each discharge contributor is less than the power distribution input, controlling the operation of the energy storage farm such that each discharge contributor delivers an amount of power equal to the updated power value determined for the discharge contributor and each charge contributor delivers an amount of power equal to at least a portion of the difference between the power distribution input and the sum of the updated power values for each discharge contributor.

19. The method of claim 17, wherein the power distribution input corresponds to a charging input associated with power to be received by the energy storage farm, further comprising, when the sum of the updated power values for each charge contributor is less than the power distribution input, controlling the operation of the energy storage farm such that each charge contributor receives an amount of power equal to the updated power value determined for the charge contributor and each discharge contributor receives an amount of power equal to at least a portion of the difference between the power distribution input and the sum of the updated power values for each charge contributor.

20. The method of claim 17, wherein, during a charging event, the initial power value for each discharge contributor in the energy storage system is equal to zero and, during a discharging event, the initial power value for each charge contributor in the energy storage system is equal to zero.