WO1999060417A1 - Method for testing overhead power lines, measuring device and use of same - Google Patents

Method for testing overhead power lines, measuring device and use of same Download PDF

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Publication number
WO1999060417A1
WO1999060417A1 PCT/CH1999/000199 CH9900199W WO9960417A1 WO 1999060417 A1 WO1999060417 A1 WO 1999060417A1 CH 9900199 W CH9900199 W CH 9900199W WO 9960417 A1 WO9960417 A1 WO 9960417A1
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WO
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Application
Patent type
Prior art keywords
characterized
che
unit
kan
anspr
Prior art date
Application number
PCT/CH1999/000199
Other languages
German (de)
French (fr)
Inventor
Alf Corrodi Markees
Original Assignee
Korona Messtechnik Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08Locating faults in cables, transmission lines, or networks
    • G01R31/081Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/085Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
    • GPHYSICS
    • G08SIGNALLING
    • G08GTRAFFIC CONTROL SYSTEMS
    • G08G1/00Traffic control systems for road vehicles
    • G08G1/01Detecting movement of traffic to be counted or controlled
    • G08G1/042Detecting movement of traffic to be counted or controlled using inductive or magnetic detectors

Abstract

The invention relates to a method for testing overhead power lines to permit the detection of defects. The method consists in measuring and recording electromagnetic signals near an overhead line by means of an antenna (A). The recorded signals are analyzed in at least two frequency bands in the frequency response and/or time range. In addition, other information, such as the position, any spoken text, etc. is recorded synchronously with the electromagnetic signals. The invention further relates to a device for carrying out this method.

Description

A method for inspection of electrical power lines as well as a measuring device and uses thereof

The present invention relates to a method for testing of electrical cables, and a measuring device, and uses thereof.

In electric lines, in particular for high-voltage overhead lines, comparatively little damage to the cables and insulators can already result in energy losses. It should be noted that damage over time become larger and in extreme cases lead to short circuits, which have the effect that the power transmission is interrupted or has to be. It is therefore of utmost importance to subject the overhead lines and the related components of a periodic review. Therefore the energy losses can be minimized and the reliability are increased.

An apparatus for the detection of so-called corona discharges in alternating current overhead lines has been described in the European patent EP-0225337. In this known teaching is a

Control device consisting essentially of an antenna, an amplification unit and an oscilloscope, wherein the signals received via the antenna are frequency-adapted in the amplification unit such that upon application of an input circuit of the oscilloscope for vertical and horizontal deflection during undisturbed sinusoidal AC line voltage a circle on the screen of the oscilloscope (also referred to as about Lissajous figure) is illustrated. Will also receive interfering signals in addition to the sinusoidal mains alternating voltage, these cause a change of the usual appearance on the screen of the oscilloscope. Because of these changes, it is possible to make a diagnosis of the defect.

It has been shown that the diagnostic ability of the known control device is highly dependent on the selected transmission function for the amplification unit and that therefore all possible phenomena can not be detected. are beyond

keep overlays of various transmission lines difficult apart.

The present invention therefore has for its object to provide a method that a unique

allows the detection of defects or of spark formation and the determination of the type of error.

This object is solved by the features specified in patent claim 1. Advantageous embodiments of the invention as well as a measuring device and their uses are given in further claims.

The invention has the following advantages: By measured electromagnetic signals in at least two frequency bands are analyzed in the frequency domain in the time and / or can be made a very accurate diagnosis of the nature of the defect in the transmission line.

The invention is explained below in more detail, for example, reference to a drawing. The single figure shows a block diagram of an inventive measuring device.

In the figure, connected to an antenna measuring unit A ME is shown, which in turn is connected via three interfaces SEI SE3 having a computational unit. The measuring unit ME consists of a signal splitter SP which splits the received using the antenna A electromagnetic signal into two channels.

The first channel consists of a series connection of a first filter unit TP, an analog / digital

ADL converter unit and the interface unit SEI. In the illustrated embodiment, the first channel in addition an acoustic display unit on AK, which also acts on the output signal of the first filter unit TP and allows an acoustic monitoring.

The second channel consists of a series connection of a highpass filter unit HP, two A / D converter units ADH1 and ADH2 and an interface unit SE2 In order for the second channel is further divided into two sub-channels.

The division into two channels using the signal splitter SP is made, on the one hand, in the second channel, to take account of the different forms of discharges which occur in overhead lines. As is known in particular that in the corona and in the peak discharge in the frequency range differences with respect to spark discharges occur. Corona and point discharges produce frequencies up to 10 MHz,

Such spark discharges up to 100 MHz and more. The electromagnetic signals associated with the frequencies for spark discharge thus have a duration of a few nanoseconds to about 100 nanoseconds. On the other hand it is of the utmost importance and the background signal, which has a substantially lower frequency, for example 50 or 60 Hz, to be able to undergo a certain analysis. It has been shown that low-frequency changes in the basic signal - for example, by existing in the vicinity of overhead power lines trees, bushes or the like. - may arise. This low-frequency changes are detected with the aid of the first channel, whereby appropriate measures - z. As cases of too tall tree - can be taken in good time prior to the occurrence of a failure in power transmission.

The inventive method in which an analysis of the signal received with the antenna A electromagnetic signals in the frequency domain and / or in the time domain is carried out, in different frequency bands, an extremely comprehensive and accurate detection of flaws is achieved on the power line.

In this case, in order to return to the illustrated embodiment in the single figure, which is provided in the inventive apparatus for recording first "slow" signals and the second channel for recording "fast" signals.

The first and slow channel which is scanned, for example with a Abtasträte of 50 kHz, permits the registration prolonged changes of the carrier signal, that is, the fundamental signal for power transmission over the transmission line. Such

Changes can - as mentioned - by a too close growth on the overhead line (trees, shrubs, etc.) are caused. In addition, the signal of the first channel after the filtering in the low pass filter unit TP (for example, a headset), where an acoustic display unit, so that an operator of the inventive apparatus can control the audio signal registered entries. Similarly, the operator (not shown in the figure) visually inspect the signal during the measurement on an output connected to the computational unit screen.

Between the signal splitter SP and the analog / digital converter unit ADL or acoustic display unit AK the first filter unit TP is provided, which prevents aliasing, that is designed in accordance with the sampling theorem.

At the entrance of the second, so-called "fast" channel, the background signal is significantly reduced by the high-pass filter unit HP. Thus it is possible, over a time window and via an existing per subchannel trigger with a positive or negative threshold value briefly signals any form - this is bipolar, positive or negative - of existing subsurface, ie signals having frequencies above the cutoff frequency of the high pass filter to discriminate, and register and for example with a sampling rate of 100 MHz or higher, the shape of the "fast" to analyze signals, which analysis may in turn be made in the time and / or in the frequency domain. In other words, the recording of the measured electromagnetic signals in the second channel takes place in a preferred embodiment of the inventive process only if one or both of the above-mentioned threshold values ​​are exceeded by the measured electromagnetic signal.

For a proper allocation of the first channel to the second and vice versa, in a preferred embodiment of the invention, a trigger channel is provided in which a trigger signal is recorded, when the second, that is, fast channel starts recording.

With the inventive device, in particular by the division into two channels according to the foregoing, it becomes possible to reduce the enormous amount of data to a necessary minimum, since it is only then carried out a data recording means of the second, the "fast" channel if need be reckoned with the fact that signal components are present in the upper frequency band.

Another, not shown in the figure

Embodiment of the invention is carried out by means of a channel with a high sampling rate data recording, wherein the high data rate then reducing with the aid of a Dezimationsalgorithmuses (RE Crochiere et. Al., "Multirate Digital Signal Processing", Prentice-Hall Inc., Englewood Cliffs, NJ, 1983), if no high-frequency signal components are included in the measured signal. By reducing the data rate of the dynamic range of the measured signals is automatically improved beyond.

The inventive device is equipped with a highly precise clock U, and with means for determining the GPS position, for example with the so-called Global Positioning System, wherein it is provided to record the corresponding data in synchronization with the measured electromagnetic signals. Moreover, in a further embodiment of the invention to record additional information about a special keyboard or a microphone and storing in synchronism with the measured electromagnetic signals. For storing the additional information mentioned or location information or time information that an own channel is made available for recording for each of the aforementioned types of information can be provided.

In a further embodiment of the invention, the means consist GPS to determine the current position in the fact that, starting from a known position of an overhead line tower (reference position) and the known velocity of the measuring apparatus along the

the current position is calculated by a time measurement transmission line. Thus miscalculations be avoided, it is provided to update the reference position continuously by again referring to a well-known position in the field.

It has been shown that the inventive method and the inventive device can be used particularly advantageously at manned (z. B. helicopter) or unmanned aerial vehicles (eg. B. drones).

Especially for a fully automatic signal analysis, it is intended to use in the computational unit, an expert system whose knowledge is enriched with the possible defects and their characteristics so that an independent analysis can be performed by the system. In a further embodiment of the invention, the expert system is designed such that due to the newly detected faults internal knowledge is adjusted, that is, the expert system is capable of learning. A further embodiment of the invention is that more than one, preferably two antennas for receiving electromagnetic signals are provided. In order for a straightening effect is achieved, ie based on the measured signals can be told where the source of the spark is. For each antenna, a complete measurement device of the type described can be provided. however, conceivable, and preferable is an embodiment variant in which the measuring device with the corresponding number of channels is equipped with the possibility that a fast and a slow channel only for about an antenna received signals is provided and for which over the other antenna received signals is only a slow channel.

The inventive measuring device can be used not only for detection of flaws for overhead lines. It has been shown that the inventive device is suitable in general also excellent for detection of electric spark. This results in a number of applications such as the detection of sparks in electric motors, in generators for generating electrical energy or overhead lines that with insufficient contact of the contact wire line through the current collector bow.

With the inventive measuring device is further opened up the field of application traffic count by passing vehicles are detected due to the spark. The use of the inventive device for traffic counting is particularly impressive because of the low installation costs because conventional devices require consistently high installation costs. So wires are involved in the pavement surface or mount on this. In the inventive measuring device, the installation simple placement on each side of the road exhausted. Furthermore, additional information on the passing vehicles can be determined with the inventive measuring device. It can be concluded on the type of vehicle on the firing pattern on the engine type and about this.

For completeness, it is pointed out that the use of two or more antennas is extremely advantageous also in the above-mentioned applications. So any defects can be located directly, for example in the review of large engines.

Claims

Patentanspr├╝che;
1. A process for ├ £ berpr├╝fung overhead electrical lines, wherein the method is
that electromagnetic signals in the Nähe the overhead line über an antenna (A) are measured and recorded,
that the recorded signals are analyzed into at least two Frequenzbändern,
that the signal analysis in the frequency and / or takes place in the time domain, whereby defects on the power line are determined based on the information obtained by the analysis results, and
that means (GPS) for determining the current position of the antenna (A) are provided with respect to the overhead line.
2. The method according to claim 1, characterized in that the means (GPS) determined current position of the antenna (A) with the measured electromagnetic signals to be recorded.
3. The method according to claim 1 or 2, characterized in that the measured electromagnetic signals and to the means (GPS) determined current position of the antenna (A) prior to recording and / or prior to analyzing be digitized.
4. The method according to one of Ansprüche 1 to 3, characterized in that the recording of the measured electromagnetic signals takes place in at least two Kanälen that have different sampling rates, wherein the data of measured signals are marked in such a way that a temporal allocation of at least two Kanäle can be made.
5. The method according to any one of the preceding Ansprüche, characterized in that the data of the channel or be subjected Kanäle with lower sampling rate a continuous analysis and that the data of the channel or Kanäle with hö herer sampling rate recorded only upon detection of a predetermined event and / or an analysis be subjected.
6. The method according to any one of the preceding Ansprüche, characterized in that synchronism of spoken text, time information, location information topographic conditions, etc. is recorded to the recorded electromagnetic signals zusätzliche information preferably.
7. The method according to any one of the preceding Anspr├╝che, characterized in that due to the analysis by means of an expert system, the kind of a detected defect on the power line is determined.
8. The method according to claim 7, characterized in that the expert system comprises an expert knowledge is adapted on the basis of the preceding analyzes, flaws improved.
9 includes measuring device comprising a measuring unit (ME) and at least one connected with this antenna (A), characterized in that the measuring unit (ME) comprises at least two Kanäle in which the über one of the antennas (A) received electromagnetic signals are processed, and that at least one interface unit (SEI, SE2) is provided to which the data processed in the at least two electromagnetic signals are Kanälen übertragbar.
10. Apparatus according to claim 9, characterized in that one of the at least two Kanäle least one filter unit (TP, HP), at least one analog / digital converter unit (ADL, ADH1, ADH2) and at least one interface unit (SEI, SE2) , wherein the filter unit (TP, HP) über the analog / digital converter unit (ADL, ADH1, ADH2) with the interface unit (SEI, SE2) is connected.
11. The apparatus of claim 9 or 10, characterized in that the filter units (TP, HP) (SP) is preceded by a signal splitter which divides by the antenna (A) received signals in two Kanäle.
12. The device according to claim 11, characterized in that the second channel is divided into two Unterkanäle, which each have an analog / digital converter unit (ADH1, ADH2).
13. The device according to one of Anspr├╝che 9 to 12, characterized in that in the measurement unit (ME) means (GPS) for determining the location, preferably in the form of satelitengestutzten Global Positioning Systems, are provided.
14. The device according to one of Anspr├╝che 9 to 13, characterized in that the interface units (SEI, ..., SE3) are standardized interfaces to which a computing unit (PC), preferably a handels├╝blicher computer connectable is.
15. Use of the device according to one of Anspr├╝che 9 to 14 for the method according to any one of Durchf├╝hrung
Anspr├╝che 1 to 8.
16. Use of the device according to one of Anspr├╝che 9 to 14 for radio detection, particularly for detection of St├╢rungen in radio, to the radio detection at
Electric motors, at Fahrdrahtleitungsübergängen and generators for generating electrical energy.
17. Use according to claim 16 for VerkehrsZählung in road traffic.
PCT/CH1999/000199 1998-05-15 1999-05-12 Method for testing overhead power lines, measuring device and use of same WO1999060417A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CH1084/98 1998-05-15
CH108498 1998-05-15

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU3593099A AU3593099A (en) 1998-05-15 1999-05-12 Method for testing overhead power lines, measuring device and use of same

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007035488A2 (en) * 2005-09-15 2007-03-29 Honeywell International Inc. Arc fault detection and confirmation using voltage and current analysis
WO2007070942A1 (en) * 2005-12-23 2007-06-28 Deakin University Method and apparatus for detecting an event
WO2008019634A1 (en) * 2006-08-15 2008-02-21 Siemens Aktiengesellschaft Model-based method for monitoring a power supply network, and system for carrying out said method
US7460346B2 (en) 2005-03-24 2008-12-02 Honeywell International Inc. Arc fault detection and confirmation using voltage and current analysis
CN105006151A (en) * 2015-07-06 2015-10-28 中国船舶重工集团公司第七一〇研究所 Dynamic vehicle detection method based on weak magnetic sensor

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986007160A1 (en) * 1985-05-21 1986-12-04 Korona Messtechnik Gossau Device for the detection of corona discharges in alternating current overhead lines
US5294937A (en) * 1992-05-20 1994-03-15 Cable Leakage Technologies Cable leakage monitoring system
EP0745863A1 (en) * 1995-05-29 1996-12-04 Schneider Electric Sa Electronic discharge detector for electrical apparatus
US5608328A (en) * 1994-11-18 1997-03-04 Radar Engineers Method and apparatus for pin-pointing faults in electric power lines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986007160A1 (en) * 1985-05-21 1986-12-04 Korona Messtechnik Gossau Device for the detection of corona discharges in alternating current overhead lines
EP0225337B1 (en) * 1985-05-21 1989-09-20 Korona Messtechnik Gossau Device for the detection of corona discharges in alternating current overhead lines
US5294937A (en) * 1992-05-20 1994-03-15 Cable Leakage Technologies Cable leakage monitoring system
US5608328A (en) * 1994-11-18 1997-03-04 Radar Engineers Method and apparatus for pin-pointing faults in electric power lines
EP0745863A1 (en) * 1995-05-29 1996-12-04 Schneider Electric Sa Electronic discharge detector for electrical apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7460346B2 (en) 2005-03-24 2008-12-02 Honeywell International Inc. Arc fault detection and confirmation using voltage and current analysis
WO2007035488A2 (en) * 2005-09-15 2007-03-29 Honeywell International Inc. Arc fault detection and confirmation using voltage and current analysis
WO2007035488A3 (en) * 2005-09-15 2007-05-18 Honeywell Int Inc Arc fault detection and confirmation using voltage and current analysis
WO2007070942A1 (en) * 2005-12-23 2007-06-28 Deakin University Method and apparatus for detecting an event
WO2008019634A1 (en) * 2006-08-15 2008-02-21 Siemens Aktiengesellschaft Model-based method for monitoring a power supply network, and system for carrying out said method
CN105006151A (en) * 2015-07-06 2015-10-28 中国船舶重工集团公司第七一〇研究所 Dynamic vehicle detection method based on weak magnetic sensor

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