GB2437315A

GB2437315A - Diagnostic signal processor

Info

Publication number: GB2437315A
Application number: GB0700198A
Authority: GB
Inventors: Mitsuhito Kamei; Chieko Nishida
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2006-04-21
Filing date: 2007-01-05
Publication date: 2007-10-24
Anticipated expiration: 2027-01-05
Also published as: DE102007001143A1; CN101059547A; JP5078276B2; HK1110655A1; JP2007292501A; CN101059547B; DE102007001143B4; GB0700198D0; GB2437315B

Abstract

A diagnostic signal processor for diagnosing partial discharges within gas insulated equipment, comprising a sensor module (2) which decomposes an electromagnetic wave signal detected by a partial-discharge sensor (1) that detects the electromagnetic wave signal propagating within the gas-insulated equipment, into a plurality of feature quantities corresponding to various physical quantities represented by the waveform of the signal and then collects the feature quantities, wherein the feature quantities to be collected by the sensor module (2) are set at positive and negative first-wave crest values A and B, the half-value width W t of the first-wave crest value, the envelope waveform y of a high-frequency signal, the attenuation time constant T of the high-frequency signal, the pulse interval information W T between partial-discharge signals, and a pulse density N. The diagnostic signal processor can flexibly cope with the alterations of various processing conditions. A host signal processor (3) governs the sensor module (2) and designates the required feature quantities. Preferably a plurality of partial-discharge sensors (1a - 1d) and a plurality of sensor modules (2a - 2d) are governed by the host processor.

Description

DIAGNOSTIC SIGNAL PROCESSOR

This invention relates to a diagnostic signal processor which is used for a diagnosis system for diagnosing partial discharges within a gas-insulated equipment.

Prior-art typical methods which concern partial-discharge signal processing for a *gas-insulated equipment are, for example, signal processing methods disclosed in JP-A-2001-242212 and JP-A-2001-183411.

The method stated in JP-A-2001-242212 detects the signals of partial-discharge sensors and converts the signals into the data of the half-value widths and crest values thereof, and it thereafter intends to presume what is a dischaige source, in accordance with the values of the ratios of the data.

On the other hand, the technique disclosed in JP-A-2001-183411 has the function of starting a timer at the moment of the detection of a partial-discharge signal and then storing partial-discharge signals developing in succession, as partial-discharge information items in time sequence, and it accepts loading-voltage-phase information items also upon the start of the timer. Further, it superposes both the information items, thereby to find those developing-phase-dependencies of partial discharges on the basis of which it intends to presume what is a discharge source.

With either of the prior-art methods as mentioned above, an information processing system which collects only the predetermined information items from the signals of the partial-discharge sensors along a predetermined information processing algorithm is included, and the processing by the system is executed to obtain the answer. Moreover, a rule for finally presuming the discharge source is fixed, and all the sensors are subjected to the identical processing, so that the processing function of the system is fixed. In a case where a request has been made for information processing which cannot be coped with by the predetermined signal processing rule, for example, the difference of noise environments on spots, or the change of any partial-discharge source which is to be preponderantly managed, on account of the working term of the gas-insu at-d-equipment, the system needs-tobe remade from --the beginning. Besides, even when detailed information items are to be further collected upon the development of the partial-discharge detection signal, means for collecting the new additional information items is not prepared, and a technician needs to be dispatched to the spots. These drawbacks have been serious problems in the aspect of cost and the aspect of operation.

In addition, with either of the prior-art techniques as mentioned above, in a case where the number of the partial-discharge sensors has increased on account of the enlargement of the gas-insulated equipment, or the like, the information processing system having the same information processing algorithm is repeatedly enlarged, and system general-control software needs to be remade in order that the information processing system may function as one new system in which' data corresponding to the system enlargement are involved. This drawback has formed serious restrictions in the aspect of cost and the aspect of the time limit of delivery.

This invention has been made in order to eliminate the problems of the prior art as stated above, and it has for its object to obtain a diagnostic signal processor for a gas-insulated equipment, which includes sensor modules each converting a partial-discharge signal within the gas-insulated equipment, into a plurality of feature quantities representative of the features of a waveform, and then collecting the feature quantities, and in which a host system is endowed with the configurator function of designating and deriving the necessary information items to be collected by the individual modules, at will in sensor units, whereby the alterations of various processing conditions can be flexibly coped with.

Another object of this invention is to obtain a diagnostic signal processor in which the same sensor modules are increased for the sensor increase based on the enlargement of a gas-insulated equipment, or the like, and in which only configurator information items are rewritten, whereby the enlargement can be flexibly coped with at a low cost.

A further object of this invention is to obtain a diagnostic signal processor for a gas-insulated equipment, in which even the collection of new information items at the development of a partial-discharge detection signal can be flexibly coped with at a low cost by rewriting only configurator information items from a remote site.

A diagnostic signal processor according to this invention consists in comprising a partial-discharge sensor which detects an electromagnetic wave signal propagating within-a-gas-jnsulated equipment, anda sensor modulewhich decompo3es-he--e-1ectromagnetjc wave sigu -detected--by the partial-discharge sensor, into a plurality of feature quantities corresponding to various physical quantities represented by a waveform of the signal and then collects the feature quantities, wherein the feature quantities to be collected by the sensor module are set at positive and negative first-wave crest values, a half-value width of the first-wave crest value, an envelope waveform of a high-frequency signal, an attenuation time constant of the high-frequency signal, pulse interval information between partial-discharge signals, and a pulse density.

Besides, a diagnostic signal processor according to this invention consists in that a plurality of such discharge sensors and a plurality of sensor modules are disposed, and that a host signal processor which governs the plurality of sensor modules and which accepts loading phase information is comprised, the host signal processor being endowed with a configurator function which can designate the partial-discharge sensors and which can select the sensor modules and the feature quantity information items to-be-accepted at will.

Besides, a diagnostic signal processor according to this invention consists in that standard sensor modules are increased for increase in the number of the partial-discharge sensors as based on an enlargement of the gas-insulated --equipment; aird that-mapping of the conf guratar functton f the host signal processor is expanded in correspondence with the increased sensors, thereby to cope with the enlargement of the gas-insulated equipment.

Besides, a diagnostic signal processor according to this invention consists in comprising means for altering the configurator information items within the host signal processor, through communications from a remote site, wherein ordinarily presence or absence of any partial discharge is detected, thereby to reduce information contents to-be-processed, whereas when the partial discharge has been detected, the configurator information items are altered from the remote site, so as to acquire additional information.

Besides, a diagnostic signal processor according to this invention consists in comprising a sensor which detects any abnormality of an equipment as an electric signal waveform, a sensor module which decomposes changes of a detection signal for the abnormality, into feature quantities corresponding to various physical quantities represented by the signal waveform, and then collects information items,. and a host signal processor which has a configurator function of deriving the plurality of information items collected by the sensor module, by designating necessary information items at will for the respective feature quantities.

According to the diagnostic signal processor of this -invention-j-- t is pts krle to obtain a diagnostic -signal--processor for a gas-insulated equipment, which can flexibly cope with the alterations of various processing conditions.

Besides, it is possible to obtain a diagnostic signal processor for a gas-insulated equipment, in which sensor increase based on the enlargement of the gas-insulated equipment, or the like can be flexibly coped with at a low cost by increasing the same sensor modules and rewriting only configurator information items.

Besides, it is possible to obtain a diagnostic signal processor for a gas-insulated equipment, which includes means for altering the configurator information items from a remote site, whereby even the collection of new information items at the development of a partial-discharge detection signal can be flexibly coped with at a low cost by rewriting only the configuration information items from the remote site.

The invention will be further described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a diagram showing the feature quantities of a partial-discharge waveform in Embodiment 1 of this invention; Fig. 2 is a diagram showing the arrangement of a sensor module in Embodiment 1 of this invention; Fig. 3 is a diagram showing the general view of a partial-discharge diagnosis apparatus in Embodiment 1 of this invention; Fig. 4 is a single-line connection diagram of a gas-insulated equipment in Embodiment 1 of this invention; Fig. 5 is a table showing the collection information items of individual sensors in the partial-discharge diagnosis apparatus in Embodiment 1 of this invention; Fig. 6 is a single-line connection diagram of a gas-insulated equipment in Embodiment 2 of this invention; Fig. 7 is a table showing the collection information items of individual sensors in a partial-discharge diagnosis apparatus in Embodiment 2 of this invention; Fig. 8 is a diagram showing a partial-discharge diagnosis apparatus in Embodiment 3 of this invention; and Figs. 9A and 9B are tables showing the changes of the collection information items of individual sensors in the partial-discharge diagnosis apparatus in Embodiment 3 of this invention.

EMBODIMENT 1: Now, a diagnostic signal processor in Embodiment 1 of this invention will be described with reference to Fig. 1 -Fig. 5.

Fig. 1 shows a typical waveform example of a partial-discharge sensor signal in Embodiment 1 of this invention.

Referring to Fig. 1, letter A denotes the first-positive-electrode crest value of a high-frequency partial- discharge signal waveform, letter B the first-negative-electrode crest value of the high-frequency signal waveform, sign t the half-value width of the first-positive-electrode crest value A, letter a function indicating the envelope of a high-frequency signal, letter T the attenuation time constant of the high-frequency signal, and T the pulse interval between partial-discharge signals.

The features of the waveform of the partial-discharge signal are represented by these quantities.

More specifically, the first-positive-electrode crest value A of the high-frequency partial-discharge signal waveform is an amplitude which corresponds to the discharge charge quantity of a partial discharge, and it can be solely said a "discharge signal". The first-negative-electrode crest value B is a signal which is obtained in such a way that the signal of the first-positive-electrode crest value A has propagated through the interior of a gas-insulated equipment and has been reflected back. This crest value B is utilized for verifying if the propagation indicates a tank interior propagation behavior, in comparison with the first-positive-electrode crest value A. The half-value width t represents a discharge signal width, and this width is known to typically become within several ns during discharge in gas. The envelope function represent-s-a proe-ss-in which -the hih'frequency discharge ---signal attenuates while being reciprocated and reflected within the tank of the gas-insulated equipment, and the desirable shape thereof is fixed by the dimensions of an inspection tank and the number of inserted spacers.

The attenuation time constant T is an index which represents the envelope function in a simple shape, and the pulse interval T represents influence which environmental changes such as ionization formed in a gas space by one partial discharge exert on the next partial discharge.

Accordingly, these feature quantities are physical quantities which affect partial discharges directly or indirectly. Further, the functions of extracting from the discharge waveform, seven sorts of information consisting of these feature quantities and that number N of partial-discharge pulses per certain time period which is added as a feature indiating how the discharges are active are afforded as a standard, whereby a partial-discharge diagnosis is permitted to cope with any situation.

Fig. 2 shows the arrangement of a sensor module which collects all the physical quantities or feature quantities mentioned above. Referring to Fig. 2, numeral 1 designates a partial-discharge sensor (hereinbelow, also simply termed the "sensor"), numeral 2 the sensor module, numeral 11 an amplifier, numerals 12 dedicated submodules which are -. --featurequantity'--extraction process,xirit-for--measuring respective feature quantities Am, Bm, ym, and Nm as indicated in Fig. 1, numeral 13 a multiplexer which selects and outputs the output of any of the submodules 12, and numeral 15 a select signal which selects the output of the multiplexer 13.

Next, the operation of the sensor module 2 for a diagnostic signal process for diagnosing partial discharges within the gas-insulated equipment will be described in conjunction with Fig. 2.

Apartial-discharge signal from the sensor], is amplified by the amplifier 11, and the amplified signal is inputted to the respective submodules 12 corresponding to the feature quantities Am, Bm, yin, --and Nm, in parallel. The individual submodules 12 measure and save information items corresponding to the predetermined feature quantities, respectively. Any of the saved information items can be selected and read out by the multiplexer 13 connected to all the submodules 12, and the selection is effected by the select signal 15 of the multiplexer 13. Accordingly, any desired feature of the partial discharge can be selected and read out by selecting the select signal 15 of the multiplexer 13 from outside.

Next, a constructional example of a partial-discharge diagnosis apparatus actually constructed by utilizing such a sensor module 2 is shown in Fig. 3.

Referring to Fig. 3, signs la id denote -part 1-discharges-ens-ors (a -d), signs-2a 2d senso odu-les-- (a -d), numeral 3 a host signal processor which collects the signals of the respective sensor modules 2a -2d so as to make: a diagnosis, numeral 5 a gas-insulated equipment, and numeral loading phase information.

Next, the operation of the diagnosis apparatus for diagnosing partial discharges within the gas-insulated equipment will be described in conjunction with Figs. 2 and 3.

The outputs of the individual partial-discharge sensors la -id mounted in the gas-insulated equipment 5 are respectively inputted to the corresponding sensor modules 2a -2d. The respective built-in submodules 12 of the sensor modules 2a -2d individually measure and save the signal feature quantities Jxn, Bm, yin, and Nm for the signals sent from the partial-discharge sensors la -id.

In such a state, the host signal processor 3 which governs the sensor modules 2a -2d designates these sensor modules in succession and affords the select signals 15, thereby to acquire the feature quantities of the partial-discharge signals detected by the corresponding sensors la -id. The acquired feature quantities can be employed for the diagnosis.

Besides, on this occasion, the host signal processor 3 separately accepts the loading phase information 20, whereby the dependencies between respective feature quantity --information items---and---lading phases-cair be--utilized as diagnosis information items.

Next, a method by which the host signal processor 3 designates the feature quantities that are to be collected from the individual sensor modules 2a -2d will be described in conjunction with Figs. 4 and 5.

Fig. 4 is a single-line connection diagram of the gas-insulated equipment or switchgear (GIS) 5, in which letters a -n denote the partial-discharge sensors that are mounted in the various places of the GIS 5.

Fig. 5 is a configurator table for designating the information items which the host signal processor 3 sets for designating the feature quantities of the respective partial-discharge sensors. In the configurator table, letters A, B, , ... and N denote the feature quantities.

Incidentally, for the sake of convenience, it is assumed that a line in which the partial-discharge sensor n in Fig. 4 is mounted is stopped, so a circuit breaker is open.

Referring to Fig. 4, the sensors a, b, rn and n are the partial-discharge sensors which are disposed in line feeders, and which are used for diagnosing the soundness of the line feeders. The other partial-discharge sensors are used for diagnosing the soundness of buses.

By way of example, if an internal abnormality should have occurred in the GIS to develop into an accident, a bus accident will -lead-to-acomi1ete -service interruption- n-whiclr-a i the lines are stopped. On the other hand, in case of the accident of each individual line, only the line is stopped, and service interruption is sometimes avoidable by power feed from another line.

Accordingly, the sensors disposed in the buses collect all the information items so as to provide against an emergency, and the sensors disposed in the lines (line feeders) serve only to detect the presence or absence of partial discharges. Then, in the configurator table of Fig. 5, the sensors a, b and are designated to collect only the feature quantities A, t and N, and circles "o" are entered into the corresponding frames thereof.

In addition, the sensors disposed in the buses are designated to collect all the feature quantities, and circles "o" are entered for all the feature quantities. Besides, since the line in which the sensor n is disposed is stopped, it need not collect any information, and any of all the feature quantities is not designated.

The host processor 3 is endowed with the basic function of designating the information items of the feature quantities marked with the circles "o", for the individual sensor modules as the select signals of the multiplexer in succession on the basis of the table. Thus, the information items corresponding to the actu]. service state of the equipment can be collected at will-from-the-individual sensor modules. ------. ---.... -EMBODIMENT 2: A diagnostic signal processor in Embodiment 2 of this invention will be described with reference to Fig. 6 and Fig. 7. The diagnostic signal processor in Embodiment 2 shows an example in the case where a gas-insulated equipment has been enlarged. Fig. 6 is a single-connection diagram example of the enlarged gas-insulated equipment (GIS), while Fig. 7 is a configurator table for designating information items which a host signal processor sets for designating the feature quantities of respective partial-discharge sensors. In the figures, letters a -t denote the partial-discharge sensors mounted in the various places of the GIS, and letters A, B, and N the feature quantities.

Next, the operation of the host signal processor in the case where the gas-insulated equipment has been enlarged will be described in conjunction with Figs. 6 and 7. Incidentally, for the sake of convenience, it is assumed that a line in which the partial-discharge sensor n in Fig. 6 is mounted is stopped, so a circuit breaker is open.

Referring to Fig. 6, the partial-discharge sensors a, b, m, n, s and t are the ones which are disposed in line feeders, and which are used for diagnosing the soundness of the line feeders. The other partial-discharge sensors are used for diagnosing the soundness of buses.

-""-"The fundamental ideas of information proces-s ng"on the" ----partial-discharge sensors for the line feeders and the partial-discharge sensors for the buses are the same as in the foregoing case in Fig. 4. In coping with the enlargement, accordingly, the partial-discharge sensors and the sensor modules are repeatedly mounted in a standard form. Besides, the host signal processor completes its preparations merely in such a way that the configurator table is expanded in correspondence with the increased sensors o -t as indicated in Fig. 7, and that the feature quantities corresponding to the respective sensors are marked with circles "o". Thus, the host signal processor 3 can automatically accept the information items also for the increased sensors 0 -t, in accordance with the basic function Of designating the information items of the feature quantities marked with the circles "o", as the select signals of the multiplexer in succession.

EMBODIMENT 3: A diagnostic signal processor in Embodiment 3 of this invention will be described with reference to Fig. 8 and Figs. 9A and 9B. The diagnostic signal processor in Embodiment 3 consists in that, in a diagnosis apparatus for diagnosing partial discharges within a gas-insulated equipment, a routine partial-discharge management and a management in the case where any partial-discharge signal has been detected are remotely altered; ----*--. -----.---Fig. 8 is a diagram showing a system in which the diagnosis apparatus for diagnosing the partial discharges within the gas-insulated equipment is coupled with a remote office by communications.

Referring to Fig. 8, signs la -id denote partial-discharge sensors (a -d), signs 2a -2d sensor modules (a -d), numeral 3 a host signal processor which collects the signals of the respective sensor modules 2a -2d so as to make a diagnosis, numeral 5 the gas-insulated equipment, and numeral the remote office.

In addition, Figs. 9A and 9B show the change of a configuration table in the case where the partial discharge has been detected in the diagnosis system in Fig. 8.

Incidentally, for the sake of convenience, it is assumed that the partial discharge has occurred at the sensor d on the single-line connection diagram in Fig. 4.

In Fig. 8, the host signal processor 3 for the partial discharges and the office 30 in a remote site are coupled by communication means, and the decided result or collected data of the host signal processor 3 can be browsed at the office in the remote site. Besides, the data of the signal processor 3 can also be altered at the office 30 in the remote site through the communication means.

In such a construction, the gas-insulated equipment is normally monitored, but a probability-at which-any-partial" -discharge actually occurs in the gas-insulated equipment is low, and monitored data hardly change in an ordinary mode. In the ordinary monitoring, therefore, the configuration table is set only for a pulse management as shown in Fig. 9A, whereby only the presence or absence of any signal is managed. Thus, information items which the host signal processor 3 and the remote office 30 ought to handle are sharply reduced.

Here, in the case where the sensor d has detected a signal which seems to indicate the partial discharge, there is the possibility that any abnormality will have occurred in the vicinity of the sensor ci. At the remote office 30, the sensor d and its adjacent sensors c, e and i.are selected on the basis of the single-line connection diagram in Fig. 4, and the configuration table is rewritten so as to contain extraordinary data request information items at the occurrence of the partial discharge as shown in Fig. 9B, through the communication means for the purpose of designating the collections of detailed feature quantities as to only the pertinent sensors. As a result, the host signal processor 3 begins to collect the detailed feature quantity information items from the designated sensors c, d, e and i, and the collected data are browsed at the remote office 30. In this way, if any accident has occurred in the gas-insulated equipment 5 on the spot can be judged immediately and without dispatching a person to the spot.

As described above, according to the diagnostic signal processor in Embodiment 1 of this invention, a standard sensor module which sequentially converts signal waveforms from a partial-discharge sensor so as to collect a plurality of feature quantities is included to establish the function of collecting the first-positive-electrode crest value and first-negative-electrode crest value of the waveform, the half-value width of the first-positive-electrode crest value, the envelope waveform of a high-frequency signal, the attenuation time constant of the highfrequency signal, the pulse interval information between partial-discharge signals, and a pulse density (the number of partial-discharge pulses per certain time period), whereby a partial-discharge signal process can flexibly cope with the change of any situation.

Besides, a plurality of sensor modules are governed by a host signal processor, and the host signal processor separately accepts loading phases, whereby the individual sensor module information items and loading phase information items can be collated.

Further, a configurator which can designate partial-discharge sensors so as to select the sensor and the information items that are to be accepted is included in the host signal processing system, whereby the changes of collected information specifications corresponding to various situation changes can be flexibly coped with as a diagnosis appartus. -In addition, according to the diagnostic signal processor in Embodiment 2, increase in the number of sensors as based on the enlargement of a gas-insulated equipment can be flexibly coped with at a low cost, merely by increasing standard sensor modules and expanding the mapping of a configurator.

Yet in addition, according to the diagnostic signal processor in Embodiment 3, means for remotely altering configurator information items is included, and ordinarily the presence or absence of any partial discharge is detected by a simple processing algorithm, thereby to reduce information contents to-be-processed, whereas when any partial discharge has been detected, additional detailed information items can be acquired by altering the configurator information items from a remote site, so that a detailed diagnosis can be remotely made.

By the way, in the above description, the case where the first wave in Fig. 1 is the positive-electrode signal, followed by the negative-electrode signal has been mentioned for the sake of convenience. However, in a case where a partial discharge has developed in the negative voltage region of a loading phase, the first wave is sometimes the negative-electrode signal, followed by the positive-electrode signal. Which ofthe positive-electrode signal and the negative'electrodestgnal develops ear-lter (whichis tht --discharge or a reflection) can be easily recognized by referring to a time difference or the loading phase, and such changes shall not exceed the purport of the construction of this invention. Needless to say, any of various existing means can be utilized for the communications between the individual sensor modules and the host signal processor, and the communications between the host signal processor and a remote office.

Furthermore, although the diagnosis apparatus according to this invention has been constructed for the use of the detection of partial discharges, it is to be understood that, when a diagnosis apparatus is constructed by altering the sorts of sensors and disposing dedicated sensor modules, it is applicable to enhancement in the flexibility of any of various monitoring systems. The fundamental concept of a diagnosis apparatus which is constituted by sensors, the extraction pre-processing of various feature quantities, and a host signal processor having a configuration function is common to this invention.

Claims

CLAIMS

1. A diagnostic signal processor comprising a partial-discharge sensor which detects an electromagnetic wave signal propagating within a gas-insulated equipment, and a sensor module which decomposes the electromagnetic wave signal detected by said partial-discharge sensor, into a plurality of feature quantities corresponding to various physical quantities represented by a waveform of the signal and then collects the feature quantities, wherein the feature quantities to be collected by said sensor module are set at positive and negative first-wave crest values, a half-value width of the first-wave crest value, an envelope waveform of a high-frequency signal, an attenuation time constant of the high-frequency signal, pulse interval information between partial-discharge signals, and a pulse density.

2. A diagnostic signal processor as defined in claim 1, wherein a plurality of such partial-discharge sensors and a plurality of such sensor modules are disposed, and a host signal processor is comprised, said host signal processor having a configurator function which can designate the partial-discharge sensors and which can select the sensor modules and the feature quantity information items to-be-accepted at will.

3. A diagnostic signal processor as defined in claim 2, wherein said host signal processor governs said plurality of sensor modules, and it accepts loading phase information.

4. A diagnostic signal processor as defined in claim 2 or 3, wherein standard sensor modules are increased for increase in the number of the partial-discharge sensors as based on an enlargement of the gas-insulated equipment, and mapping of the configurator function of said host signal processor is expanded in correspondence with the increased sensors, thereby to cope with the enlargement of the gas-insulated equipment.

5. A diagnostic signal processor as defined in any of claims 2 through 4, comprising means for altering the configurator information items within said host signal processor, through communications from a remote site, wherein ordinarily presence or absence of any partial discharge is detected, thereby to reduce information contents to-be-processed, whereas when the partial discharge has been detected; the configurator information-items-are-al-tered f roar the remote site, so as to acquire additional information.

6. A diagnostic signal processor comprising a sensor which detects any abnormality of an equipment as an electric signal waveform, a sensor module which decomposes changes of a detection signal for the abnormality, into feature quantities corresponding to various physical quantities represented by the signal waveform, and then collects information items, and a host signal processor which has a configurator function of deriving the plurality of information items collected by said sensor module, by designating necessary information items at will for the respective feature quantities.

7. A diagnostic signal processor constructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. r