METHOD OF CONTROLLING DISTRIBUTED POWER SUPPLIES

• US 20140188300A1
• Filed: 12/23/2013
• Published: 07/03/2014
• Est. Priority Date: 12/28/2012
• Status: Abandoned Application

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: NGUYEN, Khanh-Loc
• Application Number:
  US14/139,322
• Publication Number:
  US 20140188300A1
• Time in Patent Office: Days
• US Class Current: 700/297
• 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

Abstract

A method of controlling distributed power supplies is provided. In the method of controlling one or more distributed power supplies included in a microgrid, as a feeder flow control mode, an operation mode of a first distributed power supply is set, which is firstly connected to a common coupling point of the microgrid and a main grid. A second distributed power supply is selected, which is different from the first distributed power supply. A next operation mode of the second distributed power supply is determined on a basis of a current operation mode of the selected second distributed power supply and output power of the first distributed power supply. The next operation mode of the second distributed power supply is set as one of the feeder flow control mode or a unit power control mode according to the determined result.

Claims

1. A method of controlling one or more distributed power supplies included in a microgrid, the method comprising:

setting, as a feeder flow control mode, an operation mode of a first distributed power supply firstly connected to a common coupling point of the microgrid and a main grid;

selecting a second distributed power supply which is different from the first distributed power supply;

determining a next operation mode of the second distributed power supply on a basis of a current operation mode of the selected second distributed power supply and output power of the first distributed power supply; and

setting the next operation mode of the second distributed power supply as one of the feeder flow control mode or a unit power control mode according to the determined result.

2. The method according to claim 1, wherein the determining of the next operation mode comprises:

when the current operation mode of the second distributed power supply is the unit power control mode, determining an operation mode of another distributed power supply connected between the second distributed power supply and the common coupling point;

when the operation mode of the other distributed power supply is the unit power control mode, determining whether output power of the first distributed power supply is a preset maximum value or greater; and

when the output power of the first distributed power supply is the maximum or greater, determining the next operation mode of the second distributed power supply as the feeder flow control mode.

3. The method according to claim 2, further comprising, when the output power of the first distributed power supply is smaller than the maximum value, keeping the next operation mode of the second distributed power supply as the unit power control mode.

4. The method according to claim 2, further comprising, when the other distributed power supply operating in the unit power control mode does not exist between the second distributed power supply and the common coupling point, keeping the next operation mode of the second distributed power supply as the unit power control mode.

5. The method according to claim 1, wherein the determining of the next operation mode comprises:

when the current operation mode of the second distributed power supply is the feeder flow control mode, determining an operation mode of another distributed power supply connected between the second distributed power supply and the common coupling point;

when the current operation mode of the second distributed power supply is the unit power control mode, determining whether the output power of the second distributed power supply is a preset threshold value or smaller; and

when the output power of the second distributed power supply is the threshold value or smaller, determining the next operation mode of the second distributed power supply as the unit power control mode.

6. The method according to claim 5, further comprising, when the output power of the second distributed power supply is greater than the threshold value, keeping the next operation mode of the second distributed power supply as the feeder flow control mode.

7. The method according to claim 5, further comprising, when the other distributed power supply operating in the unit power control mode does not exist between the second distributed power supply and the common coupling point, changing the next operation mode of the second distributed power supply to the unit power control mode.

8. The method according to claim 1, wherein the feeder flow control mode is a distributed power supply control mode keeping, constant, power flow of a feeder to which the distributed power supplies and the main grid are connected.

9. The method according to claim 1, wherein the unit power control mode is a distributed power supply control mode keeping, constant, output powers of the distributed power supplies.

10. The method according to claim 1, further comprising changing, to a feeder flow control mode, next operation modes of other distributed power supplies sequentially operating in the unit power control mode until output power of the first distributed power supply is smaller than a preset maximum value.

11. The method according to claim 1, further comprising changing, to a unit power control mode, next operation modes of other distributed power supplies sequentially operating in the feeder flow control mode until output power of the second distributed power supply is a preset threshold value or greater.

12. The method according to claim 10, wherein the maximum value is determined by a coefficient of a droop characteristic curve when the first distributed power supply operates in the unit power control mode.

13. The method according to claim 1, further comprising:

predicting a next total consumption power variation of loads of the microgrid, and

wherein determining the next operation mode of the second distributed power supply comprises;

determining the next operation mode of the second distributed power supply on a basis of the current operation mode of the selected second distributed power supply, the output power of the first distributed power supply, and the predicted next total consumption power variation of loads of the microgrid.

14. The method according to claim 13, wherein predicting the next total consumption power variation of loads of the microgrid comprises:

predicting the next total consumption power variation of loads of the microgrid based on consumption power differences respectively corresponding to the loads, wherein each of the consumption power differences is a difference between a current consumption power and a previous consumption power of a corresponding load.

15. The method according to claim 14, wherein predicting the next total consumption power variation of loads of the microgrid based on consumption power differences comprises:

predicting the next total consumption power variation of loads of the microgrid based on a weighted sum of consumption power differences.

16. The method according to claim 15, wherein the next total consumption power variation of loads of microgrid is calculated according to the following equation: