Method for determining power flow in an electrical distribution system

Abstract

A method for determining a power flow in an electrical distribution network (104) includes determining respective feeder apparent powers of electrical power feeders (114) connected at a supply node (118) of the electrical distribution network. The method also includes determining a feeder power factor angle of at least one of the feeders responsive to the feeder apparent powers, a supply node active power, and a supply node reactive power. The method then includes using at least one of the feeder power factor angles for determining a power flow in the electrical distribution network, such as by calculating feeder active and reactive power and using these powers to provide load allocation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in the following description in view of the drawings that show:

FIG. 1 is a schematic representation of a portion of an exemplary electrical power network for which load scaling using current and power measurements may be accomplished in accordance with the present invention;

FIG. 2 is a vector diagram for an exemplary two feeder scaling solution; and

FIG. 3 is a vector diagram for an exemplary four feeder scaling solution.

Claims

1. A method for determining a power flow in an electrical distribution network comprising: determining respective feeder apparent powers of a plurality of electrical distribution network feeders receiving electrical power from a supply node of an electrical distribution network responsive to respective feeder currents in the feeders and a node voltage of the supply node;generating a system of node equations having feeder power factor angles of each of the feeders as variables and relating feeder apparent powers, a supply node active power, and a supply node reactive power;solving the system of node equations for at least one of the feeder power factor angles; andusing the feeder power factor angle for determining a power flow in the electrical distribution network.

2. The method of claim 1, further comprising calculating at least one of a feeder active power and a feeder reactive power responsive to a corresponding feeder apparent power and a corresponding feeder power factor angle.

3. The method of claim 2, further comprising generating a load scaling factor responsive to at least one of the feeder active powers and the feeder reactive powers.

4. The method of claim 3, further comprising using the load scaling factor to determine a load allocation among the feeders.

5. The method of claim 1, wherein solving the system of node equations comprises using an iterative technique.

6. A method for determining a power flow in an electrical distribution network comprising: determining respective feeder apparent powers of electrical power feeders connected at a supply node of an electrical distribution network;determining a feeder power factor angle of at least one of the feeders responsive to the feeder apparent powers, a supply node active power, and a supply node reactive power; andusing at least one of the feeder power factor angles for determining a power flow in the electrical distribution network.

7. The method of claim 6, wherein determining a feeder power factor angle comprises generating a system of node equations having feeder power factor angles of each of the feeders as variables and relating feeder apparent powers, a supply node active power, and a supply node reactive power.

8. The method of claim 7, further comprising solving the system of node equations for at least one of the feeder power factor angles.

9. The method of claim 8, wherein solving the system of node equations comprises using an iterative technique.

10. The method of claim 6, further comprising calculating at least one of a feeder active power and a feeder reactive power responsive to a corresponding feeder apparent power and a corresponding feeder power factor angle.

11. The method of claim 10, further comprising generating a load scaling factor responsive to at least one of the feeder active powers and the feeder reactive powers.

12. The method of claim 11, further comprising using the load scaling factor to determine load allocation among the feeders.

13. Computer readable media containing program instructions for determining a power flow in an electrical distribution network, the computer readable media comprising: a computer program code for determining respective feeder apparent powers of electrical power feeders connected at a supply node of an electrical distribution network;a computer program code for determining a feeder power factor angle of at least one of the feeders responsive to the feeder apparent powers, a supply node active power, and a supply node reactive power; anda computer program code for using at least one of the feeder power factor angles for determining a power flow in the electrical distribution network.

14. The computer readable media of claim 13, further comprising a computer program code for generating a system of node equations having feeder power factor angles of each of the feeders as variables and relating feeder apparent powers, a supply node active power, and a supply node reactive power.

15. The computer readable media of claim 14, further comprising a computer program code for solving the system of node equations for at least one of the feeder power factor angles.

16. The computer readable media of claim 15, further comprising a computer program code for solving the system iteratively.

17. The computer readable media of claim 13, further comprising a computer program code for calculating at least one of a feeder active power and a feeder reactive power responsive to a corresponding feeder apparent power and a corresponding feeder power factor angle.

18. The computer readable media of claim 17, further comprising a computer program code for generating a load scaling factor responsive to at least one of the feeder active powers and the feeder reactive powers.

19. The computer readable media of claim 18, further comprising a computer program code for using the load scaling factor to determine load allocation between the feeders.