ENERGY STORAGE SYSTEM AND METHOD OF CONTROLLING THE SAME

• US 20110291479A1
• Filed: 01/12/2011
• Published: 12/01/2011
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: Hanwha Solutions Corporation (Hanwha Corporation)
• Original Assignee: Samsung SDI Company Limited
• Inventors: LEE, Sung-Im
• Granted Patent: US 8,941,263 B2
• Time in Patent Office: Days
• US Class Current: 307/43
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02P 90/50 Energy storage in industry with an added climate change mitigation effect

Abstract

An energy storage system and a method of controlling the energy storage system are disclosed. The energy storage system includes an integrated controller configured to determine a functional state of a power converting unit, a bidirectional converter, and a bidirectional inverter based on conditions of the power generation system, the battery, and the load.

Claims

1. A method of controlling an energy storage system connected to a power generation system, a battery, a grid, and a load, the method comprising:

determining whether the grid is connected to the load; and

determining whether power is generated by the power generation system,

wherein the energy storage system operates in one of a plurality of modes, based on at least one of the amount of power generated by the power generation system, the charge state of the battery, the amount of power needed to charge the battery, the amount of power discharged from the battery, the amount of power to be consumed by the load, the current time, whether the grid is connected to the load, and whether power is generated by the power generation system.

2. The method of claim 1, wherein, if the grid is connected to the load, power is generated by the power generation system, and the charge state of the battery is greater than a reference value indicating that the battery is fully charged, the mode of the energy storage system is determined by comparing the amount of power generated by the power generation system and the amount of power to be consumed by the load.

3. The method of claim 1, wherein, if the grid is connected to the load, power is generated by the power generation system, and the charge state of the battery is less than a reference value indicating that the battery is fully charged, the mode of the energy storage system is determined by comparing the amount of power generated by the power generation system and the amount of power needed to charge the battery.

4. The method of claim 1, wherein, if the grid is connected to the load and power is generated by the power generation system, the mode of the energy storage system is determined based on the charge state of the battery and the current time.

5. The method of claim 1, wherein, if the grid is connected to the load and no power is generated by the power generation system, the mode of the energy storage system is determined based on the charge state of the battery and the current time.

6. The method of claim 1, wherein, if the grid is connected to the load, no power is generated by the power generation system, and the charge state of the battery is greater than a reference value indicating that the battery is fully charged, the mode of the energy storage system is determined by based on whether the current time corresponds to a time when the load is expected to consume an amount of power greater than that provided by the energy storage system.

7. The method of claim 1, wherein, if the grid is connected to the load, no power is generated by the power generation system, and the charge state of the battery is less than a reference value indicating that the battery is fully charged, the mode of the energy storage system is determined based on whether the current time corresponds to a time when the load is expected to consume an amount of power greater than that provided by the energy storage system and whether the charge state of the battery is less than a reference value indicating that the battery is fully discharged.

8. The method of claim 1, wherein, if the grid is not connected to the load and power is generated by the power generation system, the mode of the energy storage system is determined based on the amount of power generated by the power generation system and the amount of power to be consumed by the load.

9. The method of claim 8, wherein, if the amount of power generated by the power generation system is greater than the amount of power to be consumed by the load, the mode of the energy storage system is determined based on the charge state of the battery.

10. The method of claim 8, wherein, if the amount of power generated by the power generation system is less than the amount of power to be consumed by the load, the mode of the energy storage system is determined by comparing the amount of power generated by the power generation system and the amount of power needed to charge the battery.

11. The method of claim 8, wherein, if the amount of power generated by the power generation system is less than the amount of power to be consumed by the load, the mode of the energy storage system is determined based on the amount of power generated by the power generation system, a minimum amount of power to be consumed by the load, and the charge state of the battery.

12. The method of claim 11, wherein, if the amount of power generated by the power generation system is less than the minimum amount of power to be consumed by the load and the charge state of the battery is below a reference value indicating that the battery is fully charged, the mode of the energy storage system is determined based on the magnitude of a direct current (DC) link voltage.

13. The method of claim 1, wherein, if the grid is not connected to the load and no power is generated by the power generation system, the mode of the energy storage system is determined based on the amount of power discharged from the battery and the amount of power to be consumed by the load.

14. The method of claim 13, wherein, if the amount of power discharged from the battery is greater than the amount of power to be consumed by the load, the mode of the energy storage system is determined based on the charge state of the battery.

15. The method of claim 1, wherein, if the grid is not connected to the load and no power is generated by the power generation system, the mode of the energy storage system is determined based on the charge state of the battery.

16. The method of claim 15, wherein, if the charge state of the battery exceeds a reference value indicating that the battery is fully discharged, the mode of the energy storage system is determined based on whether the amount of power discharged from the battery is greater than the amount of power to be consumed by the load.

17. The method of claim 16, wherein, if the amount of power discharged from the battery is less than the amount of power to be consumed by the load, the mode of the energy storage system is determined based on the minimum amount of power to be consumed by the load.

18. An energy storage system connected to a power generation system, a battery, a grid, and a load, the energy storage system comprising:

a power converting unit configured to convert voltage output from the power generation system to a DC link voltage;

a bidirectional convertor configured to operate in one of a first discharging mode for converting power output from a battery voltage to the DC link voltage and a first charging mode for converting the DC link voltage to a charging voltage of the battery;

a bidirectional inverter configured to operate in one of a second discharging mode for converting the DC link voltage to alternated current (AC) voltage for the grid and a second charging mode for converting the AC voltage of the grid to the DC link voltage; and

an integrated controller configured to determine functionality of the power converting unit, the bidirectional converter, and the bidirectional inverter based on states of the power generation system, the battery, and the load.

19. The energy storage system of claim 18, wherein the integrated controller is configured to determine functionality of the power converting unit, the bidirectional converter, and the bidirectional inverter based on whether the grid is connected to the load and whether power is generated by the power generation system.

20. The energy storage system of claim 19, wherein the integrated controller is configured to determine functionality of the power converting unit, the bidirectional converter, and the bidirectional inverter based on at least one of an amount of power generated by the power generation system, a charge state of the battery, an amount of power for charging the battery, an amount of power to be consumed by the load, and a current time.