Power storage system and method of controlling the same

• US 8,938,323 B2
• Filed: 12/28/2010
• Issued: 01/20/2015
• Est. Priority Date: 02/25/2010
• Status: Active Grant

• Current Assignee: Hanwha Solutions Corporation (Hanwha Corporation)
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Sung-Im
• Primary Examiner(s): ORTIZ RODRIGUEZ, CARLOS R
• Application Number:
  US12/980,224
• Publication Number:
  US 20110208370A1
• Time in Patent Office: 1,484 Days
• Field of Search: 700/291, 700/295, 700/297, 700/298
• US Class Current: 700/297
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 9/062 for AC powered loads

Abstract

A method of controlling a power storage system for supplying power to a load from a power generation system, a battery, and a grid includes: when power failure occurs in the grid, determining whether duration of the power failure is more than a standard duration; if the duration of the power failure is more than the standard duration, determining a state of charge of the battery; and when the power failure of the grid has ended, if the duration of the power failure is less than the standard duration or if the state of charge of the battery is equal or more than a standard value, performing a first power failure returning mode; and if the charging condition of the battery is less than the standard value, performing a second power failure returning mode. Accordingly, the power storage system performs a stable operation and prevents lifespan shortening of the battery.

Claims

1. A method of controlling a power storage system which supplies power to a load by connecting the load to a power generation system, a battery, and a grid, the method comprising:

when a power failure occurs in the grid, determining whether a duration of the power failure between a beginning and an end of the power failure is more than a standard duration;

if the duration of the power failure is more than the standard duration, determining the power failure is a permanent failure;

if the duration of the power failure is less than the standard duration determining the power failure is an instantaneous failure,

if the power failure is the permanent failure, determining whether a charging condition of the battery indicates that a state of charge of the battery is equal to or greater than a standard value;

if the power failure is the permanent failure and the state of charge of the battery is equal to or more than the standard value, performing a first power failure returning mode; and

if the power failure is the permanent failure and the state of charge of the battery is less than the standard value, performing a second power failure returning mode.

2. The method of claim 1, wherein the first power failure returning mode comprises:

stopping a supply of power from the power generation system or the battery to the grid for a predetermined period of time;

matching a phase of the power generated by the power generation system with a phase of power of the grid; and

after the predetermined period of time has passed, supplying the power generated by the power generation system to the grid or the load.

3. The method of claim 1, wherein the second power failure returning mode comprises:

determining an amount of power consumption of the load;

when the amount of power consumption of the load is equal to or more than a standard load value, returning to the first power failure returning mode; and

when the amount of power consumption of the load is less than the standard load value, charging the battery.

4. The method of claim 3, wherein the second power failure returning mode comprises:

determining whether the power generation system is generating power; and

when the power generation system is generating power, comparing an amount of power generated by the power generation system and an amount of power required to charge the battery.

5. The method of claim 4, wherein the second power failure returning mode further comprises:

when the amount of the power generated by the power generation system is equal to or more than the amount of power required to charge the battery, charging the battery by using the power generated by the power generation system, and supplying surplus power remaining after the charging of the battery, from among the power generated by the power generation system, to the load or the grid.

6. The method of claim 4, wherein the second power failure returning mode further comprises:

when the amount of the power generated in the power generation system is less than the amount of power required to charge the battery, charging the battery by using the power generated in the power generation system and a power of the grid.

7. The method of claim 3, wherein the second power failure returning mode comprises:

determining whether the power generation system is generating power; and

when the power generation system is not generating power, charging the battery by using power of the grid.

8. The method of claim 1, wherein:

the first power failure returning mode comprises returning the power storage system to a state which existed prior to the power failure and without charging the battery; and

the second power failure returning mode comprises returning the power storage system to the state which existed prior to the power failure and charging the battery.

9. A power storage system for supplying power to a load and which connects the load to a power generation system, a battery, and a grid, the power storage system comprising:

a battery management system which controls a charging and a discharging of the battery and which determines a state of charge of the battery; and

a central controller comprising a duration determination unit which determines a duration of a power failure which occurred in the grid, to determine whether the power failure is an instantaneous failure or a permanent failure, and when the power failure in the grid has ended, performs a power failure returning mode selected from multiple power failure returning modes according to the determined duration of the power failure and the determined state of charge of the battery,

wherein when the determined duration of the power failure is equal to or more than a standard duration, the duration determination unit determines that the power failure is the permanent failure,

wherein when the determined duration of the power failure is less than the standard duration, the duration determination unit determines that the power failure is the instantaneous failure,

wherein when the determined state of charge of the battery is equal to or more than a standard value, the central controller selects and performs a first power failure returning mode, and

wherein when the power failure is the permanent failure and when the determined state of charge of the battery is less than the standard value, the central controller selects and performs a second power failure returning mode.

10. The power storage system of claim 9, wherein, the first power failure returning mode comprises a mode in which a supply of power from the power generation system or the battery to the grid is stopped for a predetermined period of time.

11. The power storage system of claim 9, wherein the second power failure returning mode comprises a mode in which the battery is charged by using power of the power generation system or the grid.

12. The power storage system of claim 9, wherein:

the central controller further comprises a power consumption determination unit which determines an amount of power consumption of the load,

when the determined amount of power consumption of the load is equal to or more than the standard value, the central controller performs a first power failure returning mode in which a supply of power from the battery to the grid is stopped for a predetermined period of time, and

when the determined amount of power consumption of the load is less than the standard value, the central controller performs a second power failure returning mode in which the battery is charged by using power generated by the power generation system or power of the grid.

13. The power storage system of claim 12, wherein the central controller:

detects an amount of the power generated by the power generation system in the second power failure returning mode, and

when the detected amount of the power generated in the power generation system is equal to or more than an amount of power required to charge the battery, controls the power storage system to charge the battery by using the power generated by the power generation system and to supply surplus power remaining after the charging of the battery, from among the power generated by the power generation system, to the load or the grid.

14. The power storage system of claim 12, wherein the central controller:

detects an amount of the power generated in the power generation system in the second power failure returning mode, and

when the detected amount of the power generated in the power generation system is less than an amount of power required to charge the battery, controls the power storage system to charge the battery by using the power generated in the power generation system and the power of the grid.

15. The power storage system of claim 12, wherein the central controller:

detects an amount of the power generated by the power generation system in the second power failure returning mode, and

when the power generation system is not generating power, controls the power storage system to charge the battery by using the power of the grid.

16. The power storage system of claim 9, wherein,

one of the power failure returning modes comprises returning the power storage system to a state which existed prior to the power failure and without charging the battery;

and

another one of the power failure returning modes comprises returning the power storage system to the state which existed prior to the power failure and charging the battery.

17. A computer readable recording medium having embodied thereon a computer program for controlling a power storage system which supplies power to a load by connecting the load to a power generation system, a battery, and a grid, said computer readable recording medium containing instructions for:

when a power failure occurs in the grid, determining whether a duration of the power failure between a beginning and an end of the power failure is more than a standard duration;

if the duration of the power failure is more than the standard duration, determining the power failure is an permanent failure;

if the duration of the power failure is less than the standard duration, determining the power failure is an instantaneous failure,

if the power failure is permanent failure, determining whether a charging condition of the battery indicates that a state of charge of the battery is equal to or greater than a standard value;

if the power failure is the permanent failure and the state of charge of the battery is equal to or more than the standard value, performing a first power failure returning mode; and

if the power failure is the permanent failure and the state of charge of the battery is less than the standard value, performing a second power failure returning mode.

18. The computer readable recording medium of claim 17, wherein the first power failure returning mode comprises:

stopping a supply of power from the power generation system or the battery to the grid for a predetermined period of time;

matching a phase of the power generated by the power generation system with a phase of power of the grid; and

after the predetermined period of time has passed, supplying the power generated by the power generation system to the grid or the load.

19. The computer readable recording medium of claim 17, wherein the second power failure returning mode comprises:

determining an amount of power consumption of the load;

when the amount of power consumption of the load is equal to or more than a standard load value, returning to the first power failure returning mode; and

when the amount of power consumption of the load is less than the standard load value, charging the battery.

20. The computer readable recording medium of claim 19, wherein the second power failure returning mode comprises:

determining whether the power generation system is generating power; and

when the power generation system is generating power, comparing an amount of power generated by the power generation system and an amount of power required to charge the battery.

21. The computer readable recording medium of claim 20, wherein the second power failure returning mode further comprises:

when the amount of the power generated by the power generation system is equal to or more than the amount of power required to charge the battery, charging the battery by using the power generated by the power generation system, and supplying surplus power remaining after the charging of the battery, from among the power generated by the power generation system, to the load or the grid.

22. The computer readable recording medium of claim 20, wherein the second power failure returning mode further comprises:

when the amount of the power generated in the power generation system is less than the amount of power required to charge the battery, charging the battery by using the power generated in the power generation system and a power of the grid.

23. The computer readable recording medium of claim 19, wherein the second power failure returning mode comprises:

determining whether the power generation system is generating power; and

when the power generation system is not generating power, charging the battery by using power of the grid.

24. The computer readable recording medium of claim 17, wherein:

the first power failure returning mode comprises returning the power storage system to a state which existed prior to the power failure and without charging the battery; and

the second power failure returning mode comprises returning the power storage system to the state which existed prior to the power failure and charging the battery.