Singularity locator

Patent metadata

Field	Value
Publication number	US-2016209458-A1
Application number	US-201414915976-A
Country	US
Kind code	A1
Filing date	Sep 3, 2014
Priority date	Sep 4, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

The present invention provides a singularity locator that enables a singularity such as a fault to be located even in a near-end section. One embodiment of the present invention is a singularity locator ( 1 ) that locates a singularity by comparing a transmission wave with a reflected wave of the transmission wave reflected at the singularity at which impedance changes. The transmission wave is a frequency modulated continuous-wave (FMCW) with a continuously modulated frequency, and the singularity is located based on a difference in frequency between the transmission wave and the reflected wave.

First claim

1 . A singularity locator that locates a singularity in one overhead transmission line by comparing a transmission wave input to an input/output point in the one overhead transmission line with a reflected wave of the transmission wave output from the input/output point after propagation through the one overhead transmission line in an opposite direction following reflection at the singularity at which impedance changes, characterized in that:
the transmission wave is a frequency modulated continuous-wave (FMCW) with a continuously modulated frequency, the transmission wave is input from the singularity locator to the overhead transmission line via a coupling filter and a capacitance transformer, the reflected wave is output to the singularity locator through the overhead transmission line via the capacitance transformer and the coupling filter, and the singularity is located based on a difference in frequency between the transmission wave of the FMCW and the reflected wave.

2 . A singularity locator that locates a singularity in one overhead transmission line by comparing a transmission wave input to an input/output point in the one overhead transmission line with a reflected wave of the transmission wave output from the input/output point after propagation through the one overhead transmission line in an opposite direction following reflection at the singularity at which impedance changes, characterized by comprising:
an FMCW generation means for generating a frequency modulated continuous-wave (FMCW) as the transmission wave that has a continuously modulated frequency; a semiconductor circuit for canceling the transmission wave of the FMCW routed to a reception circuit that receives the reflected wave; semiconductor multiplication means for generating a beat wave from a difference in frequency between the transmission wave of the FMCW and the reflected wave; and a low-frequency band pass filter for extracting a low frequency component from the beat wave, wherein the FMCW generation means and the semiconductor circuit are connected to the one overhead transmission line via a coupling filter and a capacitance transformer

3 . The singularity locator according to claim 2 , characterized by comprising a balancing transformer connected to a plurality of overhead transmission lines.

4 . The singularity locator according to claim 2 , characterized by further comprising:
semiconductor storage means for pre-storing the FMCW; digital-analog conversion means for converting a digital signal into an analog signal; and control means for controlling the digital-analog conversion means using a semiconductor logic circuit, wherein the control means allows the digital-analog conversion means to output a signal with an analog waveform, and the FMCW generation means is a wide-band electronic amplifier that receives the signal with the analog waveform to continuously output the signal with the FMCW.

5 - 7 . (canceled)

Assignees

• Fujikura Ltd
• Electric Power Dev Co

Inventors

• Kumamoto Yuji
• Shibayama Keishi
• Amano Kazuo

Classifications

• G01R31/11 Primary

  using pulse reflection methods · CPC title

• G01R31/085

  in power transmission or distribution lines, e.g. overhead · CPC title