Method and apparatus for a remote electric power line conductor faulted circuit current, conductor temperature, conductor potential and conductor strain monitoring and alarm system.

• US 20060087322A1
• Filed: 10/21/2004
• Published: 04/27/2006
• Est. Priority Date: 10/21/2004
• Status: Active Grant

• Current Assignee: Marmon Utility, LLC
• Original Assignee: Hendrix Wire & Cable Incorporated (Berkshire Hathaway Incorporated)
• Inventors: McCollough, Norman D. Jr.
• Granted Patent: US 7,187,275 B2
• Time in Patent Office: Days
• US Class Current: 324/500
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: G01R 31/2839 using signal generators, power supplies or circuit analysers G01R31/2879 takes precedence; multimeters G01R15/12, network analysers G01R27/28

Abstract

An electric power line characteristic apparatus and monitoring method allows automatic conductor faulted circuit data logging of average nominal and maximum magnitudes of conductor current, voltage, temperature, and strain. Additionally an alarm is implemented to enunciate a faulted condition of the power line. Parametric data storage is provided for later retrieval by a remote exciter 3. The electric power line conductor faulted circuit monitoring system 2 uses transducers for conductor current 260, conductor temperature 270, conductor strain 280, and conductor potential 290 monitoring and data conversion. Further, the faulted circuit current monitoring system additionally illuminates a light emitting diode LED 250 on the device in response to exceeding pre-programmed limits of the stored data. The apparatus and method includes, from a remotely located exciter 3 apparatus using an antenna 5 to transmit a specific frequency and code key to an antenna 10 of an electric power line conductor faulted circuit monitoring system 2, for retrieval of current magnitude data, conductor temperature data, conductor strain data and power line potential data associated with the electric power line phase conductor. Further, the method and apparatus logs a date and time stamp of the faulted event or other strain, temperature, and loss of potential events for later retrieval. Additionally, the method and apparatus includes a programmable in-rush delay contained in memory 210 internal to the faulted circuit monitoring device 2 to allow a remotely programmable delay time from the exciter 3 before the faulted circuit monitor 2 responds to the instantaneous re-application of power to the phase conductors P1, P2, and P3 after a conductor fault. This programmable period of time for the current to settle to a nominal value constitutes an inrush delay time before the faulted circuit monitor responds to the current level flowing in the power line conductor. The method and apparatus includes a real time clock and calendar 230 internal to the faulted circuit monitor for placing an event date and time stamp in memory 210 of the occurrence of the fault. The apparatus and method further includes the step of, at the conductor fault current monitor 2, in response to a specific rf frequency and code key, transmitted by exciter 3 and antenna 5 a specific signal in response to convey data. The data are received at the exciter 3 and stored into the exciter memory 130 for later downloading to a host PC 4. The apparatus and method collects data from multiple faulted circuit monitors 2 in the exciter 3 and stores the data in the exciter memory 130 for downloading to a host pc 4. Power for the faulted circuit monitoring system 2 is derived from the power line 1 induced potential in the coil 340 and charge pump circuitry 320 and a “super capacitor” to store charge when power lines have no current flowing in them. Power for the faulted circuit monitoring system 3 is also derived by rectifying the received specific frequency in the receiver RX 310 to supply direct current to the charge pump 320. Thus the system does not necessarily require a battery 330 although one may be used in the faulted circuit monitor system. Finally, the apparatus and method include an LED 250 for visual indication of a fault condition to an observer on the ground.

Claims

1. A method for determining a nominal and maximum current flow in the electric power line conductors 1 under normal or faulted circuit conditions, conductor temperature, conductor strain, and conductor potential, the method comprising:

(a) in the field environment, applying a specific frequency activation signal and code key from an exciter positioned proximate to the faulted circuit monitoring apparatus located on the power line conductor;

(b) at the exciter, detecting a data signal from the faulted circuit monitor, The data produced by modulating a specific frequency from the faulted circuit monitor in response to measured current, temperature, potential, and strain parameters;

(c) at the exciter, receiving the parametric data from the data signal;

(d) associating the faulted circuit current magnitude, temperature, strain, and potential with the conductor phase information for the particular faulted circuit monitor unit

(e) repeating steps (a), (b), (c), and (d) for all power line phase conductors P1, P2, and P3,

(f) and storing the data and phase conductor information in the memory of the exciter for downloading to a host pc.

2. The method of claim 1 wherein applying a specific activation signal comprises applying an un-modulated signal having a specific frequency chosen to resonate with an rf detection circuit of the faulted circuit monitor.

3. The method of claim 1 where in the fault current response time of the faulted circuit monitor is slowed to allow for “

inrush”

conditions on the power line.

4. The method of claim 3 wherein slowing the faulted circuit monitor to allow for “

inrush”

conditions on the electric power lines comprises sending a delay time value to the faulted circuit monitor from the exciter.

5. The method of claim 2 wherein applying a specific frequency activation signal comprises applying a specific frequency or two distinct frequencies close to one another.

6. The method of claim 1 wherein applying a specific activation signal comprises positioning the exciter apparatus near the faulted circuit monitor to actuate the faulted circuit monitor with the specific frequency signal.

7. The method of claim 1 wherein a specific code key pattern of binary data are transmitted from the exciter by modulation of the rf signal.

8. The method of claim 1 wherein the faulted circuit monitor apparatus responds to only a match with the exciter transmitted code key.

9. The method of claim 1 wherein detecting a data signal from the faulted circuit monitor comprises:

detecting faulted circuit current magnitude, conductor temperature, conductor strain, and conductor potential information from the faulted circuit monitor data signal.

10. The method of claim 1 wherein detecting the data signal from the faulted circuit monitor comprises:

detecting an impedance modulation of a radiated rf field of the exciter; and

decoding the data as the impedance modulation by operation of the faulted circuit monitor.

11. The method of claim 10 comprising sequentially associating detected identification information with respective power line conductor phases.

12. The method of claim 1 wherein downloading the faulted circuit monitor data stored in the exciter memory comprises communicating data over a hard wire link, a wireless link, or a network to a host pc.

13. The method of claim 12 wherein communicating data to a host pc comprises:

establishing a temporary connection between the exciter and the host pc;

conveying the data from the exciter to the host pc over the temporary connection, and breaking the temporary connection.

14. The method of claim 4 wherein comprising the faulted circuit monitoring device ignoring the current magnitude for a delay period of time after restoration of current on the power line conductor as set by the data signal sent from the exciter.