Sensing downed power lines

• US 6,459,998 B1
• Filed: 07/19/2000
• Issued: 10/01/2002
• Est. Priority Date: 07/24/1999
• Status: Expired due to Fees

• Current Assignee: Hoffman, Gary R.
• Original Assignee: Hoffman, Gary R.
• Inventors: Hoffman, Gary R.
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/619,516
• Time in Patent Office: 804 Days
• Field of Search: 700/286, 700/292, 700/293, 700/294, 700/295, 700/296, 702/57, 702/58, 702/59, 702/60, 702/61, 702/62, 361/62, 361/63, 361/64, 361/65, 361/66, 361/67, 361/68, 340/657, 340/661
• US Class Current: 702/62
• CPC Class Codes: H02H 1/0076 by superposition on the watched current
• CPC Class Codes: H02H 5/10 responsive to mechanical injury, e.g. rupture of line, breakage of earth connection

Abstract

In systems embodying the invention, a “downed” power line is detected by sensing whether there is an open circuit along the power line and producing an indication that an open circuit condition exists. In response to an indication that an open circuit condition exists, the system compares the nature of the voltage and/or current signals present on the power line at the time an open circuit condition is indicated to exist, with a preprogrammed stored condition which includes typical signals to be expected when a “break” occurs along a power line. When a downed power line is detected, power is then removed from the affected line.

Claims

1. Apparatus for sensing a break along a power conductor which is used to distribute electrical power from an origination point and then along the conductor to a termination point, comprising:

a first means coupled to the origination point of the conductor;

a second means connected to a point along the conductor between the origination point and the termination point of the conductor;

said first and second means being in communication with each other for producing a first signal when there is an interruption in the distribution of power along the conductor between the first and second means; and

sensing and recording means coupled to the origination point of the conductor for sensing and recording the characteristic of the electrical signals present at, or reflected to, the origination point of the conductor for enabling said sensing and recording means to sense and record the electrical signal present at the origination point at all times, including the time when the first signal is produced.

2. Apparatus as claimed in claim 1, wherein a power source is coupled to the origination point of the conductor via a power switching device, and wherein when the electrical signals sensed along the conductor at the time of the disruption of communication between the first and second communication means correspond to the prerecorded signals to be expected when a break occurs along a conductor, the power switching device is operated so as to interrupt the coupling of the power source to the conductor.

3. Apparatus as claimed in claim 2, wherein the power source is an alternating current (AC) power source.

4. Apparatus as claimed in claim 1, wherein said first and second means communicate with each other along said conductor whereby any open circuit condition along the conductor causes the interruption of communication between the first and second means.

5. Apparatus as claimed in claim 4, wherein the first means includes signal receiving circuitry;

and wherein the second means includes means for sensing the presence of electrical power being distributed along the conductor and also includes transmitting circuitry for sending coded messages along the conductor to the signal receiving circuitry of the first means located at the origination point.

6. Apparatus as claimed in claim 4, wherein at least one of said first and second means generates said first signal in response to the interruption of communication between the first and second means and wherein said first signal is applied to said sensing and recording means for evaluating the characteristic of the electrical signal generated at the origination point at the time of the interruption of communication along the conductor.

7. Apparatus as claimed in claim 6 wherein said sensing and recording means also includes memory means for storing pre-recorded characteristic information of the electrical signal to be expected at the origination point when disruption of power along a conductor occurs, including the electrical signal to be expected at the origination point when a break occurs along a conductor;

and wherein said first signal causes the electrical signal sensed at the time of the disruption of communication between the first and second communication means to be compared to said prerecorded information.

8. Apparatus as claimed in claim 7 wherein the sensing and recording means includes analog-to-digital (A/D) converter circuitry and wherein said first and second means are each capable of at least doing one of transmitting and receiving signals.

9. Apparatus as claimed in claim 1 wherein a first transceiver is coupled to the origination point of the conductor and a second transceiver is coupled to the termination point of the conductor;

said first and second transceivers being in communication with each other for producing a first signal when there is a disruption in the distribution of power along the conductor.

10. Apparatus as claimed in claim 9 wherein said first and second transceiver communicate with each other via radio signals.

11. Apparatus as claimed in claim 9 wherein said recording means to sense and record the electrical signal present at the origination point at all times includes a first memory circuit in said first transceiver and wherein said first transceiver also includes a second memory circuit for storing pre-recorded characteristic information of the electrical signal to be expected at the origination point when disruption of power along a conductor occurs.

12. An electrical power distribution system comprising:

first storage means for storing information pertaining to selected characteristics exhibited by a downed power line;

circuitry coupled to a power line for sensing selected characteristics of the power being distributed along the power line and for storing the sensed information in a second storage means;

circuitry coupled to the power line for sensing the presence of an open circuit on the power line; and

circuitry responsive to the presence of an open circuit condition for comparing information stored in the second storage means with information stored in the first storage means.

13. A system as claimed in claim 12 wherein said circuitry responsive to the presence of an open circuit condition for comparing information stored in the second storage with information stored in the first storage means also includes circuitry for producing a signal indicating whether the information sensed and stored in the second storage means corresponds to characteristics exhibited by a downed power line.

14. A system as claimed in claim 13, wherein said power line has an origination point and a termination point;

and

wherein said circuitry coupled to a power line for sensing selected characteristics of the power being distributed along the power line and for storing the sensed information in a second storage means includes a first circuit coupled to the origination point of the power line;

wherein said circuitry coupled to the power line for sensing the presence of an open circuit on the power line includes a second circuit connected to a point along the power line between the origination point and the termination point and wherein said first and second circuits being in communication with each other for producing a first fault signal when there is an interruption in the distribution of power along the power line; and

wherein the circuitry responsive to the presence of an open circuit condition for comparing information stored in the second storage means with information stored in the first storage means produces a signal interrupting the application of power to the origination point if the signal stored in the second storage means corresponds to the signature of a downed power line.

15. Apparatus for sensing a break along a power conductor which is used to distribute power from an origination point and then along the conductor to a termination point, comprising:

first communication means coupled to the origination point of the conductor;

second communication means connected along the conductor between the origination point and the termination point of the conductor;

said first and second communication means communicating with each other along said conductor, whereby any open circuit condition along the conductor causes the interruption of communication between the first and second means;

sensing and recording means coupled to the origination point of the conductor for continuously sensing and recording selected characteristics of the electrical signals present at, or reflected to, the origination point of the conductor;

wherein at least one of said first and second communication means generates a first signal in response to the interruption of communication between the first and second communication means and wherein said first signal is applied to said sensing and recording means for evaluating the characteristic of the electrical signal generated at the origination point at the time of the interruption of communication along the conductor.

16. Apparatus as claimed in claim 15 wherein said sensing and recording means also includes memory means for storing pre-recorded characteristic information of the electrical signal to be expected at the origination point when disruption of power along a conductor occurs, including the electrical signal to be expected at the origination point when a break occurs along a conductor;

and wherein said first signal causes the electrical signal sensed at the time of the disruption of communication between the first and second communication means to be compared to said prerecorded information.

17. Apparatus as claimed in claim 16, wherein a power source is coupled to the origination point of the conductor via a switching means, and wherein when the signals sensed at the time of the disruption of communication between the first and second communication means are comparable to the prerecorded signals to be expected when a break along a conductor occurs, a signal is produced and applied to the switching means for interrupting the coupling of the power source to the conductor.

18. Apparatus comprising:

a conductor having an origination point and a termination point;

a power source;

a normally enabled switching means connected between the power source and the origination point of the conductor;

said switching means, when enabled, coupling the power source to the origination point of the conductor for enabling distribution of power along the conductor;

a first transceiver coupled to the origination point of the conductor;

a second transceiver coupled along the conductor between the origination point and the termination point;

said first and second transceivers being in communication with each other for producing a first signal when there is a disruption in the distribution of power along the conductor;

sensing and recording circuitry coupled to the origination point of the conductor for sensing and recording selected electrical signals generated at the origination point of the conductor for disabling the switching means in response to a predetermined signal condition at the origination point and to the presence of said first signal.

19. Apparatus as claimed in claim 18 wherein said predetermined signal condition corresponds to a signal which is normally produced when a conductor is physically ruptured.

20. Apparatus as claimed in claim 18 wherein said first and second transceivers communicate with each other along the conductor.

21. Apparatus as claimed in claim 18 wherein said first and second transceivers communicate with each other via a radio link.

22. A method for interrupting power distribution along a power line comprising the steps of:

sensing selected characteristics of the power being distributed along a power line and storing the information in a first memory;

sensing the presence of an open circuit condition on a power line;

comparing information corresponding to selected ones of the characteristics stored in the first memory with prestored data identifying characteristics exhibited when there is a break on the power line, in response to sensing the presence of an open circuit on the power line; and

interrupting the application of power to the portion of the power line before the break.

23. A method as claimed in claim 22, wherein said power line has an origination point to which power is applied and a termination point;

and wherein the step of sensing selected characteristics of the power distributed includes circuitry for sampling the selected characteristics at the origination point.

24. A method as claimed in claim 22, wherein the step of sensing the presence of an open circuit condition on a power line includes the connection of a first communication means at the origination point and a second communication means at a point along the power line between the origination point and the termination point.

25. A method as claimed in claim 22, wherein the step of comparing information includes the step of pre-recording and storing in a data storage circuit the pre-stored data identifying characteristics which are exhibited when there is a break in the power line, and the step of comparing the information stored in the first memory with the information in the data storage circuit.