LINE BREAK DETECTION SYSTEM

• US 20150115742A1
• Filed: 04/01/2014
• Published: 04/30/2015
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: Nexans Incorporated (Nokia Corporation)
• Original Assignee: Nexans Incorporated (Nokia Corporation)
• Inventors: Willis, Barber Kenneth, Michael, Lee
• Granted Patent: US 9,983,250 B2
• Time in Patent Office: Days
• US Class Current: 307/125
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: H02H 1/003 Fault detection by injection of an auxiliary voltage same for detection of earth fault currents H02H3/17; for monitoring earth connection H02H5/105

Abstract

A line break detection system for detecting a break in a conductor (1.004), the system including a first return signal generator (1.020) proximate a first end of a segment of the conductor, the first return signal generator being adapted to apply a first return signal to the conductor, the system including a first return signal detector (1.016) proximate a second end of the segment of the line, the second end being upstream of the first end, the first detector being adapted to receive the first return signal from the line, wherein the first return signal generator ceases to generate the first return signal if the line is broken.

Claims

1. A method of detecting a line fault on a section of a power supply line, said method comprising the steps of:

injecting a return signal at the downstream end of the section; and

detecting the return signal at the upstream end of the section.

2. The method of detecting a line fault as claimed in claim 1, including the step of removing power from the section of the power supply line in the event of failure to detect the return signal at the upstream end of the section.

3. A power supply line fault detection return signal generator (RSG) comprising:

means to generate a return signal; and

means to apply the return signal to the power supply line.

6. The return signal repeater including return signal detection means adapted to detect return signals from a RSG as claimed in claim 3, and return signal regeneration means.

4. A power supply line fault detection return signal detector (RSD) comprising:

means to receive a return signal from the power supply line;

means to analyse the return signal; and

means to produce a power line control signal in response to the presence or absence of the return signal.

5. The RSD as claimed in claim 4, including a power interruption breaker switch to remove power from the line in response to the detection of an absence of a return signal.

7. A return signal concentrator comprising:

return signal detection means adapted to detect and distinguish two or more return signals from two or more RSGs; and

return signal regeneration means adapted to produce a concentrated return signal.

8. The return signal concentrator as claimed in claim 7, wherein the concentrated return signal is adapted to indicate the presence or absence of each of the two or more return signals from the two or more RSGs.

9. A power supply line break detection system comprising:

at least one RSG, each RSG being adapted to generate a characteristic return signal which is applied to the power supply line,

wherein a RSD connected to the line upstream of the or each RSG detects the return signal to confirm continuity of the supply line, and, in the absence of the return signal, generates a fault signal.

10. The power supply line break detection system as claimed in claim 9, including a first breaker switch, the RSD being adapted operate the breaker switch to isolate the line from a source of electrical power when the RSD detects the absence of a return signal.

11. The power supply line break detection system as claimed in claim 9, wherein the RSD is adapted to associate each characteristic return signal with its corresponding RSG.

12. The power supply line break detection system as claimed in claim 9, including a return signal concentrator, adapted to receive return signals from two or more downstream RSGs, and to generate a concentrated return signal for transmission to the RSD.

13. The power supply line break detection system as claimed in claim 9, including a branch line including a corresponding branch RSG located at a distance from the junction of the second branch line, the branch RSG generating a characteristic return signal associated with the branch RSG, the system including a branch RSD located on the branch line nearer the junction of the branch line, the branch RSD being adapted to detect the characteristic return signal from the branch RSG.

14. The power supply line break detection system as claimed in claim 13, including a second breaker switch adapted to disconnect the branch line from the source of electrical power in response to a control output from the branch RSD.

15. The power supply line break detection system as claimed in claim 9, wherein the or each RSG or concentrator includes a back-up power supply to enable the RSG to continue to transmit its characteristic return signal in the event of loss of power from the line.

16. The power supply line break detection system as claimed in claim 14, wherein the RSD is adapted to receive return signals after the breaker switch has opened, and, in the event of reception of a return signal which had been temporarily interrupted, to close the breaker switch.

17. A power supply line monitoring system monitoring a segment of a power supply line, the system comprising:

a RSG at a downstream end of the segment of power supply line; and

a RSD at the upstream end of the segment of power supply line,

wherein the RSG generates a return signal and transmits the return signal to the RSD, to indicate the presence or absence of a supply voltage at the downstream end of the segment of power supply line.

18. The power supply line monitoring system as claimed in claim 17, wherein the RSG transmits the return signal wirelessly.

19. The power supply line monitoring system as claimed in claim 18, wherein the RSG transmits the return signal to the RSD in the absence of supply voltage at the downstream end of the segment of power supply line.

20. A return signal generator comprising:

a line voltage detector;

a signal generator controlled by the line voltage detector to generate a return signal; and

a wireless transmitter connected to the signal generator to transmit the return signal.