Control unit for a power-distribution network

• US 6,816,757 B1
• Filed: 09/19/2002
• Issued: 11/09/2004
• Est. Priority Date: 09/19/2002
• Status: Expired due to Term

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: De La Ree, Jaime, McElray, Jeffrey L., Fahey, Timothy, LaPlace, Carl J., Stoupis, James D.
• Primary Examiner(s): Gandhi, Jayprakash N.
• Application Number:
  US10/247,191
• Time in Patent Office: 782 Days
• Field of Search: 700/4, 700/79, 700/90, 700/286, 702/57, 702/60, 702/62, 324/76.11, 713/340
• US Class Current: 700/286
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: H02H 7/261 involving signal transmission between at least two stations transmission of signals in general H02H1/0061

Abstract

A preferred embodiment of control unit for a power-distribution network comprises a processor, a memory-storage device electrically coupled to the processor, a set of computer-executable instructions stored on the memory-storage device, and an input/output interface electrically coupled to the processor. The control unit receives data from a plurality of switching devices of a power-distribution network, identifies ones of the switching devices located immediately up-line and down-line of a fault in a faulted section of the power-distribution network based on predetermined characteristics of the data, and generates and sends a first control input to at least one of the switching devices located immediately up-line and down-line of the fault to cause the at least one of the switching devices to open and thereby isolate the faulted section from a second section of the power-distribution network.

Claims

1. A power-distribution network, comprising a plurality of switching devices and a control unit, the control unit comprising a processor, a memory-storage device electrically coupled to the processor, a set of computer-executable instructions stored on the memory-storage device, and an input/output interface electrically coupled to the processor, wherein the control unit:

receives data from the plurality of switching devises;

identifies ones of the switching devices located immediately up-line and down-line of a fault in a faulted section of the power-distribution network based on predetermined characteristics of the data; and

generates and sends a first control input to at least one of the switching devices locatedimmediately up-line and down-line of the fault to cause the at least one of the switching devices to open and thereby isolate the faulted section from another section of the power-distribution network.

2. The power-distribution network of claim 1, further comprising a first and a second voltage source, wherein the another section of the power-distribution network is energized by the first voltage source prior to the fault, and the control unit generates and sends a second control input to one of the switching devices located down-line from the faulted section, the second control input causing the one of the switching devices located down-line the faulted section to close so that the another section of the power distribution network is energized by the second voltage source after the fault.

3. The power-distribution network of claim 2, wherein the control unit compares a load condition on the another section prior to the fault with an available load capacity of the second voltage source, and generates and sends the second control input to the one of the switching devices located down-line from the faulted section only if the available load capacity of the second voltage source is sufficient to energize the another section based on the load condition on the another section prior to the fault.

4. The power-distribution network of claim 1, wherein the control unit is communicatively coupled to at least one of a data base and a central monitoring station by way of a data link.

5. The power-distribution network of claim 4, wherein the data link is a SCADA data link.

6. The power-distribution network of claim 1, wherein the at least one of the switching devices located immediately up-line and down-line of the fault comprises a sectionalizer.

7. The power-distribution network of claim 1, wherein the plurality of switching devices comprises a recloser and a sectionalizer.

8. The power-distribution network of claim 1, wherein the control unit comprises a programmable-logic controller.

9. The power-distribution network of claim 1, wherein the data comprises a loading condition on the plurality of switching devices.

10. The power-distribution network of claim 1, wherein the control unit identifies ones of the switching devices located up-line of the fault based on a substantial decrease in line voltage and a substantial increase in line current in the ones of the switching devices located up-line of the fault.

11. The power-distribution network of claim 1, wherein the control unit identifies ones of the switching devices located down-line of the fault based on one of:

(i) a substantial decrease in line current and line voltage in the ones of the switching devices located down-line of the fault, and (ii) a substantial increase in line current and a reversal of power flow in the ones of the switching devices located down-line of the fault.

12. The power-distribution network of claim 1, wherein the control unit receives the following inputs from one of the switching devices comprising a recloser;

(i) identification data;

(ii) a loading conduction;

(iii) a recloser count;

(iv) a position of an interrupting mechanism of the recloser;

(v) a locked-out status of the recloser; and

(vi) a resistance down-line of the recloser.

13. The power-distribution network of claim 12, wherein the control unit generates and sends the following inputs to the one of the switching devices comprising a recloser;

(i) an open-close command; and

(ii) a “

lock-out”

command.

14. The power-distribution network of claim 1, wherein the control unit receives the following inputs from one of the switching devices comprising a sectionalizer;

(i) identification data;

(ii) loading conditions;

(iii) an open-closed status of the sectionalizer; and

(iv) a resistance down-line of the sectionalizer.

15. The power-distribution network of claim 14, wherein the control unit generates and sends the following inputs to the one of the switching devices comprising a sectionalizer:

an open-close command; and

(ii) a “

reverse polarity”

command.

16. The power-distribution network of claim 1, further comprising a central processing unit comprising the processor, the memory-storage device, the computer-executable instructions, and a power supply electrically coupled to the processor and the memory-storage device.

17. A power-distribution network, comprising (i) a central processing unit comprising a processor, a memory-storage device electrically coupled to the processor, and a set of computer-executable instructions stored on the memory-storage device, (ii) an input/output interface electrically coupled to the central processing unit;

and (iii) a first and a second switching device, wherein;

the input/output interface receives inputs from the first and second switching devices, the inputs being indicative of a load condition on each of the first and second switching devices;

the central processing unit detects the presence a fault in a first section of the power-distribution network located between the first and second switching devices by comparing the input from the first switching device with the input from the second switching device;

the central processing unit generates a control input in response to the detection of the fault; and

the input/output interface sends the control input to at least one of the first and second switching devices, the control input causing the at least one of the first and second switching devices to reconfigure itself to isolate the first section of the power-distribution network from a second section of the power-distribution network.

18. The power-distribution network of claim 17, further comprising a third switching device and first and a second voltage source, wherein the second section of the power-distribution network is energized by the first voltage source prior to the fault, and the central processing unit and the input/output interface generate and send a second control input to the third switching device, the second control input causing the third switching device to open so that the second section of the power-distribution network is energized by the second voltage source after the fault.

19. The power-distribution network of claim 18, wherein the central processing unit compares a load condition on the second section prior to the fault with an available load capacity of the second voltage source, and the and the central processing unit and the input/output interface generate and send the second control input to the third switching device only if the available load capacity of the second voltage source is sufficient to energize the second section based on load condition on the second section prior to the fault.

20. The power-distribution network of claim 17, wherein the central processing unit further comprises a power supply electrically coupled to the processor and the memory-storage device.

21. A power-distribution network, comprising:

a first switching device electrically coupled to a first voltage source and a first section of a first distribution feeder for isolating the first section from the first voltage source in response to an overcurrent condition in the first distribution feeder;

a second switching device electrically coupled to the first section and a second section of the first distribution feeder for isolating the first section from the second section on a selective basis;

a third switching device electrically coupled to the second section and a third section of the first distribution feeder isolating the second section from the third section on a selective basis; and

a control unit comprising a processor, a memory-storage device electrically coupled to the processor, a set of computer-executable instructions stored on the memory-storage device, and an input/output interface, wherein the control unit;

(i) communicates with at least the first, second and third switching devices;

(ii) detects the presence a fault in one of the first, second and third sections by comparing loading conditions of the first, second, and third switching devices; and

(iii) generates and sends a control input to at least one of the second and third switching devices to cause the at least one of the second and third switching devices to isolate one of the first, second, and third sections from another of the fast, second, and third sections.

22. The power-distribution network of claim 21, wherein the first switching device is a recloser.

23. The power-distribution network of claim 21, wherein the second and third switching devices are sectionalizers.

24. The power-distribution network of claim 21, further comprising a second voltage source and a fourth switching device electrically coupled to the second voltage source and the third section, wherein the fourth switching device isolates the third section from the second voltage source on a selective basis.

25. The power-distribution network of claim 24, wherein the control unit communicates with the fourth switching device, and generates and a second control input to the fourth switching device, the second control input causing the fourth switching device t close so that the third section is energized by the second voltage source.

26. The power-distribution network of claim 25, wherein the control unit compares a load condition on the third section prior to the fault with an available load capacity of the second voltage source, and the control unit generates and sends the second voltage source is sufficient to energize the third section based on the load condition on the third section prior to the fault.

27. The power-distribution network of claim 21, further comprising a communication link between the control unit and at least one of the first, second, and third switching devices.

28. The power-distribution network of claim 27, wherein the communication link is a radio communication link.

29. The power-distribution network of claim 26, further comprising:

a fifth switching device electrically coupled to the second voltage source and a first section of a second distribution feeder, the fifth switching device isolating the first section of the second distribution feeder from the second voltage source in response to an overcurrent condition in the second distribution feeder,

a sixth switching device electrically coupled to the first section and a second section of the second distribution feeder the sixth switching device isolating the first section from the second section of the second distribution feeder on a selective basis; and

a seventh switching device electrically coupled to the second section and a third section of the second distribution feeder, seventh switching device isolating the second section from the third section of the second distribution feeder on a selective basis, wherein the fourth switching device is electrically coupled to the third section of the second distribution feeder and the control unit;

(i) communicates with the fifth, sixth, and seventh switching devices;

(ii) detects the presence a fault in one of the first, second, and third sections of the second distribution feeder by comparing loading conditions of the fifth, sixth, and seventh switching devices; and

(iii) generates and sends a control input to at least one of the sixth and seventh switching devices to cause the at least one of the sixth and seventh switching devices to isolate one of the first, second, and third sections of the second distribution feeder from another of the first, second, and third sections of the second distribution feeder.

30. The power-distribution network of claim 21, further comprising a substation, the substation comprising the first voltage source and a circuit breaker electrically coupled to the first voltage source and the first switching device.

31. The power-distribution network of claim 24, further comprising (i) a first substation comprising the first voltage source and a first circuit breaker electrically coupled to the first voltage source and the first switching device, and (ii) a first substation comprising the second voltage source and a second circuit breaker electrically coupled to the second voltage source and the fourth switching device.

32. The control unit of claim 21, further comprising a central processing unit comprising the processor, the memory-storage device, the computer-executable instructions, and a power supply electrically coupled to the processor and the memory-storage device.

33. A power-distribution network comprising:

a first voltage source;

a first switching device electrically coupled to the voltage source;

a second switching device electrically coupled to the first switching device down-line of the first switching device in relation to the first voltage source;

a third switching device electrically coupled to the second switching device down-line of the second switching device in relation to the first voltage source; and

a control unit for;

(i) receiving data from at least the second and third switching devices;

(ii) detecting a fault in a first section of the power-distribution network located between the second and third switching devices based on predetermined characteristics of the data; and

(iii) generating and sending a first control input to at least one of the second and third switching devices to cause the at least one of the second and third switching devices to open and thereby isolate the first section from a second section of the power-distribution network.

34. The power-distribution network of claim 33, further comprising a second voltage source and a fourth switching device located down-line of the third switching device in relation to the first voltage source and electrically coupled to the second voltage source, wherein the control unit generates and sends a second control input to the fourth switching device, the second control input causing the fourth switching device to close so that the second section is energized by the second voltage source.

35. The control unit of claim 34, wherein the control unit compares a load condition on the second section prior to the fault with an available load capacity of the second voltage source, and generates and sends the second control input to the fourth switching device only if the available load capacity of the second voltage source is sufficient to energize the second section based on the load condition on the second section prior to the fault.

36. The control unit of claim 33, further comprising (i) a central processing unit, the central processing unit comprising a processor, a memory-storage device electrically coupled to the processor, a set of computer-executable instructions stored on the memory-storage device, and a power supply electrically coupled to the processor and the memory-storage device, and (ii) an input/output interface device electrically coupled to the central processing unit.

37. The control unit of claim 33, further comprising a substation, the substation comprising the first voltage source, and a circuit breaker electrically coupled to the first voltage source and the first switching device.