Managing an energy storage system

• US 10,122,210 B2
• Filed: 12/27/2013
• Issued: 11/06/2018
• Est. Priority Date: 12/28/2012
• Status: Expired due to Fees

• Current Assignee: Aggreko LLC (Aggreko Ltd.)
• Original Assignee: Younicos Inc. (Aggreko Ltd.)
• Inventors: Gong, Huaxin, Fogarty, Audrey
• Primary Examiner(s): Fennema, Robert E
• Assistant Examiner(s): Monty, Marzia T
• Application Number:
  US14/655,655
• Publication Number:
  US 20150349587A1
• Time in Patent Office: 1,775 Days
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A system includes an energy storage system configured to supply energy to an electrical grid and a control system coupled to an energy management system of the electrical grid and configured to control the energy storage system. The control system receives one or more commands from the energy management system, and in response, executes a command compliance routine to charge or discharge energy from the energy storage system to the electric grid in accordance with the one or more commands. The control system also receives one or more system condition values from the energy storage system and one or more market condition values for the electric grid and executes a management routine to charge or discharge energy from the energy storage system to the electric grid based on the system condition values and the market condition values.

Claims

1. A method performed by a control system of an energy storage system, the method comprising:

receiving one or more commands from an energy management system of an electrical grid, and in response, executing a command compliance routine to charge or discharge energy from the energy storage system to the electrical grid in accordance with the one or more commands;

and receiving one or more system condition values from the energy storage system and one or more market condition values for the electrical grid and executing a management routine to charge or discharge energy from the energy storage system to the electrical grid by comparing a first numerical value to a second numerical value, the first numerical value based on a first difference between the one or more system condition values and a first target value, and the second numerical value based on a second difference between the one or more market condition values and a second target value, wherein, in response to determining to discharge the energy storage system, executing the management routine comprises;

sending a request to the energy management system to discharge;

receiving a reply to the request from the energy management system specifying that discharging is authorized; and

discharging the energy storage system as authorized by the reply to the request.

2. The method of claim 1, wherein the energy storage system comprises at least one energy storage device coupled to the electrical grid by a bidirectional power conversion system, and wherein receiving the one or more system condition values comprises receiving a state of charge of the at least one energy storage device.

3. The method of claim 2, wherein the first target value is a target state of charge, and wherein executing the management routine comprises executing a target state of charge routine that favors discharging the at least one energy storage device when the state of charge is above the target state of charge and favors charging the at least one energy storage device when the state of charge is at or below the target state of charge.

4. The method of claim 2, wherein the energy storage system is coupled to an intermittent power source configured to supply power to the electrical grid, and wherein executing the management routine comprises receiving one or more power system values from the intermittent power source and determining to charge or discharge the at least one energy storage device based on the one or more power system values, and wherein the power system values specify an amount of power being supplied by the intermittent power source to the electrical grid.

5. The method of claim 1 wherein at least one of the first difference or the second difference is modified based on a multiplier.

6. The method of claim 2, wherein the energy storage system is coupled to an intermittent power source configured to supply power to the electrical grid, and wherein executing the management routine comprises executing a ramp rate mitigation routine that discharges the at least one energy storage device when the intermittent power source is supplying power at a rate that is decreasing faster than a first threshold rate and charges the at least one energy storage device when the intermittent power source is supplying power at a rate that is increasing faster than a second threshold rate.

7. The method of claim 1, wherein the one or more market condition values specify a price of energy on the electrical grid, and wherein receiving the one or more market condition values comprises receiving the one or more market condition values from the energy management system.

8. The method of claim 4, wherein the second target value is a threshold price of energy, and wherein the management routine favors charging the energy storage system when a price of energy is below the threshold price of energy.

9. The method of claim 6, wherein the management routine favors discharging the energy storage system when a price of energy is above a different threshold price.

10. The method of claim 1, wherein the one or more commands includes scheduling a particular discharge event at a particular time.

11. A system comprising:

an energy storage system configured to supply energy to an electrical grid;

and a control system configured to be coupled to an energy management system of the electrical grid and configured to control the energy storage system by performing operations comprising;

receiving one or more commands from the energy management system, and in response, executing a command compliance routine to charge or discharge energy from the energy storage system to the electrical grid in accordance with the one or more commands; and

receiving one or more system condition values from the energy storage system and one or more market condition values for the electrical grid and executing a management routine to charge or discharge energy from the energy storage system to the electrical grid by comparing a first numerical value to a second numerical value, the first numerical value based on a first difference between the one or more system condition values and a first target value, and the second numerical value based on a second difference between the one or more market condition values and a second target value, wherein, in response to determining to discharge the energy storage system;

sending a request to the energy management system to discharge;

receiving a reply to the request from the energy management system specifying that discharging is authorized; and

discharging the energy storage system as authorized by the reply to the request.

12. The system of claim 11, wherein the energy storage system comprises at least one energy storage device coupled to the electrical grid by a bidirectional power conversion system, and wherein receiving the one or more system condition values comprises receiving a state of charge of the at least one energy storage device.

13. The system of claim 12, wherein the first target value is a target state of charge, and wherein executing the management routine comprises executing a target state of charge routine that favors discharging the at least one energy storage device when the state of charge is above the target state of charge and favors charging the at least one energy storage device when the state of charge is at or below the target state of charge.

14. The system of claim 12, wherein the energy storage system is configured to couple to an intermittent power source configured to supply power to the electrical grid, and wherein executing the management routine comprises receiving one or more power system values from the intermittent power source and determining to charge or discharge the at least one energy storage device based on the one or more power system values.

15. The system of claim 14, wherein the power system values specify an amount of power being supplied by the intermittent power source to the electrical grid.

16. The system of claim 12, wherein the energy storage system is configured to couple to an intermittent power source configured to supply power to the electrical grid, and wherein executing the management routine comprises executing a ramp rate mitigation routine that discharges the at least one energy storage device when the intermittent power source is supplying power at a rate that is decreasing faster than a first threshold rate and charges the at least one energy storage device when the intermittent power source is supplying power at a rate that is increasing faster than a second threshold rate.

17. The system of claim 11, wherein the one or more market condition values specify a price of energy on the electrical grid, and wherein receiving the one or more market condition values comprises receiving the one or more market condition values from the energy management system.

18. The system of claim 17, wherein the second target value is a threshold price of energy, and wherein the management routine favors charging the energy storage system when the price of energy is below the threshold price of energy.

19. The system of claim 18, wherein the management routine favors discharging the energy storage system when the price of energy is above a different threshold price.

20. The system of claim 11, wherein the one or more commands includes scheduling a particular charge event at a particular time.