CN1017829B - Method and apparatus for determining deterioration of electric power line - Google Patents
Method and apparatus for determining deterioration of electric power lineInfo
- Publication number
- CN1017829B CN1017829B CN90107791A CN90107791A CN1017829B CN 1017829 B CN1017829 B CN 1017829B CN 90107791 A CN90107791 A CN 90107791A CN 90107791 A CN90107791 A CN 90107791A CN 1017829 B CN1017829 B CN 1017829B
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- China
- Prior art keywords
- earth fault
- line
- zero phase
- omen
- electric force
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Locating Faults (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
An arrangement for detecting the position of deterioration in the properties of a power cable contains several sensors (1,1',''...) arranged at various locations along the cable which detect null phase signals and pulse signals contained in them. A circuit (3) detects a deterioration in the vicinity for which the associated sensor indicates a maximum pulse signal value. The sensor signals are passed to the evaluation circuit via a signal communications device (2). ADVANTAGE - Enables deteriorating high voltage cable characteristics to be observed which can eventually lead to earthing faults.
Description
The present invention relates to the method and system of determining line of electric force earth fault omen, particularly relate to by monitoring and cause the omen of line of electric force earth fault to judge a kind of method and system of this omen of line of electric force.
Power circuit, especially distribution line are equipped with a large amount of power equipments in extensive region, they are overhauled will spend a large amount of time and efforts, so just very need predict the earth fault omen.And and then determine the scope of this omen, but do not obtain the practical technique of this omen of prediction at present.
To this, learnt already in being entitled as Japanese patent gazette 57-20779 number (1982) of " display device of earth fault scope " that wherein, the scope of earth fault was determined, but after fault takes place, just shown.
Be installed in the appropriate location of distribution line according to the earth fault range display of above-mentioned prior art, and when being higher than a certain level, the output of a high frequency filter determines to take place earth fault, this high frequency filter is located at one in the input circuit of the earth fault signal (zero phase signals) that these position probing get, but has following problem:
1. because this installs just work after earth fault takes place, so can not predict earth fault;
2. because show, find to realize these device work before it so make an inspection tour, and may spend long time and just find it the maintainer in device installing place;
3. because of display device work when high-frequency signal level is higher than predetermined value, just have a plurality of display device work, thereby can not determine location of fault.
Consider above-mentioned situation, the objective of the invention is to monitor the omen that causes earth fault, and pre-determine this omen.
Another object of the present invention is to determine earth fault omen position.
According to the present invention, for predicting the earth fault omen of a line of electric force, be to predict according to such fact: the mains frequency component amplitude of the zero phase signals that monitors in three-phase power line does not change, but the amplitude of high fdrequency component changes; Also has such fact: comprise an odd number pulse signal in the zero phase signals that in three-phase power line, monitors.
Have, in order to determine earth fault omen position, the amplitude of monitoring zero phase signals high fdrequency component in a plurality of positions of three-phase power line simultaneously changes, and determines earth fault omen position according to its amplitude again.
When monitoring the omen of earth fault, just can predict the generation of earth fault in the present invention.Have again,, can determine location of fault by the omen of monitoring on whole line of electric force.
Because its formation makes sensor because the variation of the high fdrequency component that comprises in zero phase signals that the earth fault omen causes, and the determined device of the information of sensor is collected, then can determine earth fault omen zone according to the present invention.
Therefore, in the prior art, the operations staff makes an inspection tour on-the-spot after system breaks down immediately, from ground Direct observation distribution wire, searches earth fault omen point, this change expense a large amount of time and expenses; Yet the invention provides such method:
1. detection of ground faults premonitory phenomenon before breaking down;
2. because determined earth fault omen zone, just can prevent accident by inspection earthing fault omen part and equipment part;
3. even under the situation of unexpected fault, scope that also can the localization of faults, and can improve the efficient of service work and prevent to break down again.
And then, detect the transient change in the high fdrequency component of zero phase signals, so it is not subjected to effects of load, have again, can be as system's operation, and irrelevant with the signal transmission system of power line carrier system.
Fig. 1 is the view of expression schematic construction of the present invention;
Fig. 2 is a view of explaining earth fault omen among the present invention;
Fig. 3 is the view of the zero phase signals of expression when an earth fault taking place;
Fig. 4 is the view that omen and phenomenon of the failure are compared;
Fig. 5 to Fig. 7 is the view of sensor example;
Fig. 8 to Figure 11 is the view that earth fault omen zone principle is determined in expression;
Figure 12 to 14 is illustrated in the view of predicting in the sensing equipment;
Figure 15 is that expression can be with the view of wave filter service band of the present invention;
Figure 16 explains the view that changes normal cut-off point.
Introduce one embodiment of the present of invention below, explained earlier that before introducing what is the omen that causes a line of electric force earth fault, just what is an omen, and the phenomenon of its earth fault that should narrate from prior art is carried out clear and definite judgement.To this, a distribution wire as power circuit is carried out following explanation.
Fig. 2 is illustrated in the state of the zero phase voltage Vo that measures in the transformer station; In this voltage, in a certain amount of time, surveillance map 2(I) monitors the waveform of similar Fig. 2 (II) behind the waveform (being superimposed with pulse on the zero phase voltage first-harmonic) again, and thereafter, and then monitor the waveform of similar Fig. 2 (III) in a certain amount of time again.After producing these aperiodic waveforms, will consider that actual earth fault will finally take place, but, pulse amplitude among Fig. 2 does not have in time and a kind of like this relation of increasing, and the phase place that is produced is arbitrarily, and can not discern the cycle in the cycle that produces.Therefore, include high fdrequency component in the fundamental quantity in the precursor pulse shape waveform that in waveform Vo, comprises.Because high fdrequency component will decay when conducting by a distribution wire, then can consider, by the zero phase voltage Vo of monitoring, can perceive the generation of pulse signal earlier near the earth fault position.
Here, as an omen example pulse type waveform Vo is shown among Fig. 2, the time that pulse type Vo takes place may continue several cycles; Perhaps consider, basic high fdrequency component and primitive period comparison, the stack in short-term of its waveform is repeated, and produces excessive gradually to the earth fault omen.
Fig. 3 (a) and (b) are represented the Japanese patent gazette 57-20779(1982 as prior art) described in the waveform of earth fault, wherein high frequency waves produce in succession.To this, can differentiate similar omen in the Zero-phase current.
The omen waveform and the earth fault waveform of earth fault are compared, can notice the following relation that exists.
As an example of distribution wire equipment ground fault omen, the feature of this omen is: produce the zero phase signals that has odd number pulse type waveform.Just shown in 1 among Fig. 4, its abscissa is represented frequency, and ordinate is represented amplitude; Such feature is arranged when the earth fault omen occurring, the amplitude that is the mains frequency component is constant by its initial value, and have only pulse signal (high fdrequency component) that bigger variation is arranged, simultaneously in earth fault omen latter stage (during earth fault), high fdrequency component also increases, even the corresponding increase of mains frequency component, shown among Fig. 22.So for equipment ground fault omen, the intensity of variation of mains frequency component and high fdrequency component generally presents following phenomenon in zero phase signals.(seeing Table 1)
And then with Fig. 1 (a) with (b), (c) relatively, in the earth fault omen later stage, even all can monitor it a long way off, but can only near earth fault omen point, could monitor it in early days; The such fact of this phenomenon explanation; A line characteristic is arranged, and promptly high frequency waves are lighted along with distance increases and decays from it.And then we can say that compare with the mains frequency cycle, the cycle of pulsing is sufficiently long.
The present invention makes according to above-mentioned omen.
The installation situation of system of the present invention will be with reference to figure 1 in bottom's explanation.In Fig. 1 (a), T is that a station power distribution transformer, B are distribution bus in the distribution substation, wherein, and distribution wire isolating switch FCB
1～FCB
nConnect several distribution outlets.The distribution wire F that the picture dendroid is extended
11, F
12, F
13... F
nLink isolating switch FCB end.Just, branch line F
12, F
13, or the like require to link main line F according to diagram
11On.
As shown in the figure, sensor 1,1 ', 1 " ... be contained in optional position on these distribution wires; and, be delivered to sensing equipment 3 by an information conveyer line 2 from zero phase signals of these sensors output (based on zero phase voltage or Zero-phase current and the electric parameters being transmitted or from them, branch away on request).
Have, sensor 4 has and sensor 1 similar function again, and it is installed on the distribution bus suitably, and will be sent to sensing equipment 3 by the electric weight that main line branches away.
In a kind of like this structure, according to the present invention, the zero phase signals that obtains at the distribution system each point is collected in a place, and supposition, at distribution wire F
1-F
nCertain part the distribution wire of an earth fault omen is arranged, to describe in detail below.
To this, as the transmission line 2 that information is sent to sensing equipment 3, can be the connection of a special use, or a circuit that utilizes the carrier system of line of electric force, perhaps adopt communication device through radio channel.
The example of a system architecture of Fig. 1 (b) expression, the system of Fig. 1 in this structure (a) is connected by the wire communication circuit, wherein terminal device 10,10 ', 10 " ... comprise sensor 1,1 ', 1 " ... detect the function of zero phase signals, to high-tension distributing line F
11On each switch SW all be provided with these terminal devices, and at each terminal device 10, the secondary terminals equipment 100(in the transformer station comprises sensor 4 etc.) and the 30(of main website comprising sensing equipment 3) between constitute an order wire 2.Main website 30 by a modulator-demodular unit 31, emission receiving unit 32, signal bus 39, coupling part 33,33 ', printer 34, a CRT35, a keyboard 36, a CRT operator's console 37, operator's console 38 or the like constitutes, and 30 through a coupling part 33 ' link to each other with a distribution computer.So, 10 detected information are sent to the computing machine of main equipment 30 in the terminal station, and output on CRT35, printer 34, simultaneously from computing machine, the instruction of keyboard 36, CRT37, operator's console 38 etc. is sent to terminal station 10, thereby realized switch SW control, detection that pre-entry detects or the like.
The example of a system architecture of Fig. 1 (c) expression, this system architecture has been used a kind of known method of transmitting signal by distribution wire, and high-tension distributing line F
11Be used as order wire 2.In this case, a terminal station 10 comprises a remote control terminal station 10a, and this terminal station 10a comprises sensor 1 and the high pressure coupling mechanism 10b that is used to insulate with input, and this terminal station 10 is located at extremely going up corresponding to switch SW.In this transformer station, to each bar distribution wire F
11-F
nAll be provided with one and be used to insulate and the high pressure coupling mechanism of detection signal, and it is linked to each other with a relay.This need wherein be provided with sensing equipment 3 in transformer station and the 30(of main website) between with a large amount of transmission signals of two-forty, and they are connected by telecommunication cable.Main website 30, with the distant place control, the equipment that constitute by transmission unit TU, comprise central processing unit CPU, an operation board OP or the like, the CRT unit 41 that also has various information of output and the various clauses and subclauses of input, 42, one distribution computer of distribution system dish that are used to show the circuit electriferous state of distribution system for example or the like.As the similar signal input among Fig. 1 (b), output shows and blocked operation also can be undertaken by the system architecture of Fig. 1 (c).To this, different by the device structure of Fig. 1 (b) main website equipment with Fig. 1 (c), still be not that the function and any device structure of information operating of input, demonstration, output are provided respectively all is gratifying.To illustrate below for the structure that adopts the wire communication line.
Fig. 5 (I) is illustrated in an embodiment of terminal station 10 inner sensors 1, and this station 10 is loaded on the distribution wire with dispersing mode, and can notice the waveform of zero phase voltage Vo, and this voltage Vo comprises high fdrequency component.In other words, former zero phase voltage Vo comprises the mains frequency component or than the low order high fdrequency component of (comprising three times, five times), comprises high-order component hardly simultaneously, but it should be noted that, when abnormal conditions (as slight earth fault) took place, its waveform became and has precipitous peak value.In other words, when earth fault had taken place by a short time, zero phase voltage Vo only became very high in this time, and when earth fault disappeared, it just became and former the same low level waveform.A large amount of high fdrequency components only is included in the zero phase voltage waveform high in this short time; Simultaneously, because the equipment deterioration, slight earth fault can not continue, and in a single day takes place promptly to stop, and he occurs very high peak value Vo(needle-like continually).
So, be to catch the height of very high signal Vo peak value for son in its formation of example shown in Fig. 5 (I), the high fdrequency component value can not be separated respectively and is compared mutually by a wave filter.
Fig. 5 (I) expression is loaded on example of structure on the distribution wire with dispersing mode.
Voltage between distribution wire F and ground is by the voltage divider capacitor C
1, C
2Be admitted in any high voltage, and obtain zero phase voltage Vo by the addition of vectors computing in zero phase input circuit 4.Here, as Fig. 5 (II) (a) shown in, when at time t
1Zero phase voltage in exist a pulse type to change amplitude V
1The time, directly send into an input end of subtracter 20 by being somebody's turn to do zero phase voltage signal Vo; Also send into the output of Fig. 5 (II) shown in (b), wherein the pulse-like voltage waveform is removed by low-pass filter (LPF), this wave filter is isolated the higher harmonics of first-harmonic and low order and is removed low secondary frequency components (higher harmonics of first-harmonic and low order) from zero phase voltage Vo, only obtains the voltage V that pulse type changes in subtracter 20 outputs
1, as Fig. 5 (II) (c) shown in.The pulse type variable quantity of this voltage by analog to digital converter (A/D) digitizing, changes voltage V
1Amplitude maintain by peak- holding circuit 21,22, as Fig. 5 (II) (d) shown in.
Pulse type variation at voltage is just having, is having under the negative situation, and positive changing unit is by peak-holding circuit 21 outputs, and negative changing unit is exported by peak-holding circuit 22.When the detection level of adjusting in the output of peak-holding circuit becomes compared with moving detecting device 5 was high, starting detecting device 5 just sent an initiating signal to CPU.In this CPU, mould/number (A/D) conversion is undertaken by this initiating signal, and its digital value ratio is in changing voltage V
1Amplitude, and be removed and store; After a schedule time, at time t
2By a slot signal original state is arrived in the peak-holding circuit involution.The data of collecting in CPU with number number of their each sensor appointment after testing, detect number of times or the like, are sent to sensing equipment 3 in the main website 30 by communication part 6 and communication cable 2 together.
In this embodiment, the timing that CPU implements the A/D conversion is determined, so that the output with starting detecting device 5 is started, but, the A/D conversion can be carried out in a schedule time, and irrelevant with starting detecting device 5, perhaps initiating signal can receive from another position through communication cable 2 and communication part 6.
And then by being provided at the time clock feature in the CPU, and being added to the input data during the number of times information of same sent into and storing them and can be implemented in many places and obtain to meet data.According to prior art, Japanese patent application discloses 1-8246 number (1989) in early days and " collects the method for distribution system information ", can obtain it most effectively, and it may reach with other technology certainly.
Fig. 5 represents an embodiment who notices pulse-like voltage waveform peak height, notices high fdrequency component at another embodiment shown in Fig. 6 simultaneously.Fig. 6 illustrates another example of sensor 1 structure.
In order to take out a voltage, can adopt the capacitor among Fig. 5, but preferably adopt by a capacitor C by dividing potential drop between ground and distribution wire
1The bleeder circuit structure of forming with resistance R, and have as shown in Figure 6 different characteristic, to constitute the most effective embodiment of the present invention.After a Hi-pass filter HPF, be provided with the bandpass filter BPF of required quantity
1, BPF
2, their band-pass characteristics is for only isolating a frequency band arbitrarily, and Hi-pass filter HPF isolates the high fdrequency component that comprises in the zero phase voltage signal Vo of output, and these output quantities A/D change and digital conversion after send into CPU.When needing, needed data in the data of collection are sent to sensing equipment 3 in the main website 30 by communication part 6 and connection 2.In addition, collect the timing of representative data and can determine, or determine by receiving an initiating signal at another place by connection 2 with the starting detecting device 5 of Fig. 5.
Bottom is with reference to figure 7(a) introduce on distribution wire, disperseing to be provided with another embodiment of the sensor 1 that designs.The formation of sensor 1 will be installed two component transformer circuits, takes out bleeder circuit between distribution wire and ground, and can be from zero phase voltage bleeder circuit 4 and 4 ' acquisition feeder line F
1And F
2Zero phase voltage, its method is to connect branch pressure voltage in the switch SW both sides, with the feeder line F on distribution wire
1And F
2Between connect or disconnect, shown in Fig. 7 (a).Change in voltage testing circuit 23 and 23 ' constitute by low-pass filter LPF with to the subtracter 20 that Fig. 5 explained, and be designed to only send the precipitous variation of voltage.Data processing section 25 is made of the peak-holding circuit 21 that Fig. 5 was explained and 22 and parts, and hang oneself in the future those of A/D converter of this part are signal digitalized, and is collected in the value among the CPU.Difference detecting device 24 be added in change in voltage testing circuit 23,23 ' output terminal, obtain the difference between two inlets, and with the data aggregation in the CPU in data processing section 25.Collected data are sent to sensing equipment 3 through communication part 6 and connection 2, and its mode is identical with the explanation to Fig. 5.For this embodiment switch SW is " leading to " to reach the situation of " breaking ", makes an explanation in bottom.
When switch is " leading to "
When change in voltage testing circuit 23 was identical with 23 ' output amplitude, the difference of difference detecting device 24 was output as zero.
But, the abnormal data collecting circuit of the system that two circuit are formed the two one of when any problem is arranged, in difference detecting device 24, just produce output, thereby just can normally monitor two collecting circuits.
When switch is " breaking "
Change in voltage testing circuit 23 and 23 ' output be respectively independently, and two outputs in fact all do not have when as yet the earth fault omen not taking place.And, only can export their variation effectively when when slight earth fault has taken place one of two feeder lines.Particularly original noise (noise that thunders as a distant place) is as difference output, and this is because they enter into two distribution wires, can obtain with sensitivity when just minor failure taking place in distribution wire therein.In this case, distribution wire F
1And F
2Can be identical system's (same frequency band) or different system.
Bottom will be with reference to figure 7(b) explain two embodiment in addition that disperse to be arranged on the distribution wire.
Be differential circuit 26 and detecting device 27 with the difference of the structure of this sensor 1 shown in Fig. 7 (b), and remainder is with the same manner work.
When switch SW disconnects, zero phase voltage output circuit 4 and 4 ' output be added in the difference circuit 26, and obtain difference between these two inlets, and be sent to detecting device 27.Detecting device 27 a feasible output voltage variable signal are set, and wherein those low secondary frequency components are removed by low-pass filter LPF and subtracter, just as in change in voltage testing circuit 23.In this embodiment, if feeder line F
1And F
2Frequency band identical, difference circuit is just only exported because the change in voltage that the earth fault omen causes, this be because low secondary frequency components zero phase voltage output circuit 4 and 4 ' output in be to equate fully, just can be very low so detect level at the beginning, and obtain a highly sensitive detecting device.
This shows the high sensitivity detector that can obtain not to be subjected to zero phase signals to influence, even in the carrier wave system of using low frequency signal, for example uses in the zero phase carrier wave transmission system.For this reason, in order to take out Fig. 5 dividing potential drop between distribution wire and the ground in Fig. 7,, an electric capacity and a variable-resistance series circuit are set in mutually to every among Fig. 6 and 7 for every capacitor that is provided with mutually of Fig. 5.Therefore, can followingly carry out; Promptly in this structure, constitute the series circuit of a capacitor mutually for each, it is in parallel with ground side capacitors C that a variable resistor R is set simultaneously, so, be connected in parallel by C and R, can do paired high fdrequency component by the series capacitor circuit working, and to the component of low frequency relatively by the C+R circuit working.
Narrated the structure of the sensor 1 that is located on this distribution wire with reference to figure 5 to Fig. 7, wherein, in Fig. 6 and Fig. 7 (b), use filters H PF and BPF, be contained in pulse type component in zero phase voltage signal with output packet, require to get rid of other frequency components that in the distribution wire surrounding environment, exist by the frequency band of these filter detection.In other words, according to the present invention, when being accompanied by tiny signal that the earth fault omen produces and being detected, noise that is present in various electric waves in the distribution wire surrounding environment or the like should not be detected.
Figure 15 (a) is illustrated in the frequency band that tradition adopts in broadcasting and the communication, according to this tradition usage, adopts about 300KHz～10
4The scope of HZ is used for this purpose; From with their other viewpoint of noise phase region, determine that in this frequency band frequency band of the present invention is insuperior.Can adopt 10
4The above scope of HZ, but simple wave filter of installing is inapplicable on distribution wire.Thus, in fact should not surpass 300KHz, but in fact this scope be limited, shown in Figure 15 (b).In other words, 200～300KHz is used frequency band of Carrier of power line carrier system relay protection device among this figure, therefore should be defined as in the scope below 200KHz.And then for lower limit, the distribution wire noise increases in the following scope of 5KHz, and frequency band then of the present invention should be limited in 5KHz～200KHz.To this,, just more wish to adopt the scope of 5～30KHz so consider this situation because when surpassing 30KHz, be difficult to make at the amplifier behind the wave filter.
For Fig. 7 (a) and (b), illustrated to be equiped with two bleeder circuits, and determined that the earth fault omen has taken place which bar feeder line, simultaneously clearly, when the structure that Fig. 5 or 6 is shown is installed two sensors at the switch SW two ends, also can determine to have taken place the feed line of earth fault omen.
To this, at Fig. 7 (a) and the detecting device 24 (b) and 27 can under the simulating signal state, carry out A/D conversion, and data aggregation is gone into 25, maybe can detect the situation that predetermined value has been exceeded, and with its triggering (starting) signal as a collection earth fault precursor signal.
In other words, if can just may collect data whereby simultaneously with high-sensitivity detection to the earth fault precursor signal from sensor near two positions facing to the switch of the distribution system end of electric system.
Fig. 8 is illustrated in the sensing equipment 3, the decision algorithm of the data determination distribution wire earth fault omen section of being collected by the method for Fig. 5～7.
Abscissa represents that each sensor is loaded on the distance relation on the distribution wire, and ordinate is represented the data value that each sensor arrives.
Zero phase voltage mainly comprises the high fdrequency component that produces from the earth fault omen, and it is propagated along distribution wire, and distribution wire can be regarded L, the C distributed circuit of high-frequency range as, but should zero phase voltage decay gradually.Therefore, as shown in Figure 8, clearly, in the nearest data value maximum of the point 10 of earth fault omen point, and along with to this point apart from increase and reduce.
This can say into the amplitude (Fig. 5) or its peak value (Fig. 6) of high fdrequency component similarly.
Fig. 9 represents each frequency band high fdrequency component amplitude and attenuation, according to this situation, data set to any frequency band, all maximum at its peak value of point 10 places near earth fault omen point, frequency is high more, and the decay of distribution wire is big more, and generally the circuit decay to L, C distributed constant is little in high-frequency range, therefore, data attenuation ratio high frequency band Vo(HF lower band Vo(HEL)
H) data will be greatly.Figure 10 is illustrated in the exemplary view as the high fdrequency component ratio of earth fault precursor signal that comprises in zero phase voltage waveform.
In this drawing, abscissa is represented frequency, and ordinate is represented signal level.
In general, consider that the earth fault omen has three kinds of patterns: (a) type, every kind of comprising frequency proportions is identical; (b) type, the low frequency that comprises are basic ratio, and along with the increase frequency ratio strengthens; (c) type, the low frequency ratio is little, and along with the increase frequency ratio strengthens.
Need later on to study with the test aspect at the scene, go to determine those types specifically corresponding to the situation of a certain equipment component earth fault omen.
Figure 11 is an expression when (a) and (b) taking place and (c) during arbitrary pattern earth fault omen, the distance shown in Figure 9 and the data of amplitude are the concept maps how to change, expresses (a) and (b) and each distribution situation (c).In other words, the data of each frequency band indicate, and all are maximum at earth fault omen point 10 under any circumstance, and its amplitude is: identical under (a) situation; (b) under the situation, lower frequency is bigger; And under (c) situation, upper frequency is bigger on the contrary.
Thus, by where understanding and which type of earth fault omen takes place, just can by sensing equipment 3 definite it.
Consider the situation of detection peak sensor among Fig. 5, the processing procedure in the sensing equipment in the main website 30 will be explained by bottom.
Installing all peak detection sensors on the distribution wire among sensing equipment 3 realizations of monitoring distribution wire and Fig. 5 got in touch in any or definite time, the peak value of the high fdrequency component that in the zero phase signals of each sensor, comprises of collecting, and the earth fault omen zone of definite distribution wire.
The signal handling procedure of sensing equipment 3 has been shown in Figure 12 (a).Sensing equipment 3 is for being collected in the peak value V of the high fdrequency component that comprises in zero phase signals
OH, realize successively exporting to the contact of distribution wire end from transformer station to being located at each distributed locations sensor 1～N.According to the result of contact shown in Figure 12 (a), by grasping the high fdrequency component V that comprises in the zero phase signals that in distribution wire, distributes
OHThe amplitude situation of peak value can be determined in the example of this figure, indicates peaked sensor 10 places to have earth fault omen feature approaching.
The following explanation at the sensor 1 that is shown by Fig. 6 detected the processing in the sensing equipment 3 under the multiple frequency component situation of different frequency bands.The sensing equipment 3 of monitoring distribution wire is realized all the sensors the getting in touch in any or definite time with each distributed locations installing of distribution wire, the collect higher higher harmonic components in each sensor zero phase signals and the earth fault omen zone of definite distribution wire.
Figure 13 (a) shows and determines that equipment shows genuine handling procedure.Sensing equipment is to be collected in each the frequency component V of a plurality of frequency bands that comprises in zero phase signals
01H, realize successively the sensor 1～N that is installed in distributed locations being exported to from transformer station the contact of distribution wire end.By grasp the V that each band signal shown in Figure 11 is distributed in distribution wire
OFHThe amplitude situation just can be determined in this legend, and there is earth fault omen feature in proximity transducer 10.Here, main zero phase signals of the high fdrequency component that produces from earth fault omen point is propagated along distribution wire, and this distribution wire can be thought of as L, the C distributed circuit in high-frequency range, so the just decay gradually of this signal.And then attenuation degree also increases when number of times is higher, so if for example collect two kinds of higher harmonics V
OFH1And V
OFH2Component just becomes the situation of Figure 13 (b), and can detect earth fault omen zone more exactly.
Furtherly, when zero phase signals ripple itself when every is sent to sensing equipment 3, lean on following method also can determine earth fault omen point effectively.
In other words, the sensing equipment 3 of monitoring distribution line will with zero phase signals on the substation bus bar that distribution wire is connected and the sensor 4 that comes to be located on this distribution wire of leisure distributed locations and sensor 1,1 ', 1 " ... zero phase signals carry out periodicity and compare, and partly detect distribution wire earth fault omen scope by a simultaneous and instantaneous difference.Just, the main zero phase signals of the high fdrequency component that has produced from earth fault omen point (may be the amplitude of odd number pulse-like voltage Vo peak value, but high fdrequency component will be explained by bottom) propagate along distribution wire, this distribution wire should be thought L, the C circuit in the high-frequency range, so this signal is decayed gradually.Therefore, in the zero phase signals of the sensor of installing near the position of earth fault omen point, comprise many high fdrequency components.Just obtain overlapping zero phase signals difference, promptly detect high fdrequency component part instantaneous value, can determine earth fault omen zone from the distribution of amplitude by 2 on same distribution wire.The example of signal handling procedure in sensing equipment 3 has been shown among Figure 14.The time T of determinator 3 decision monitoring grounding fault omen states, and collect and be stored in the zero phase signals on the substation bus bar in the time T.After this, by getting in touch the amplitude of the zero phase signals that is collected in time T with each sensor.At this moment, contrast cuts from substation bus bar with from the zero phase signals amplitude of each sensor, has just detected the difference in the high fdrequency component amplitude.As above-mentioned, far away more from earth fault omen point, the high fdrequency component decay is big more, and is therefore above-mentioned to the comparison operation from all the sensors zero phase signals by finishing, and just can determine whether to exist the zone of earth fault omen and earth fault omen.To this, the zero phase signals itself that utilization is collected according to this processing is finished this comparison operation, therefore, even during transmitting (as zero phase carrier-wave transmission line) by being loaded with zero phase voltage signal line of electric force, transmission signals itself is not influenced, this is subtracted because of them is low frequency, and can detect earth fault omen zone.
More than determine the sensing equipment 3 in earth fault omen zone referring to figs. 12 to the 14 zero phase signals of having explained the sensor that is used to each distributed locations setting on the comfortable distribution wire; This sensing equipment 3 is when detecting, and just output is according to continue the earth fault omen area data that information collection or that collect is at the fixed time measured from each sensor.Specifically, in Fig. 1 (b), (c) main website with output form quoted a floppy disk 43, printer 34, a screen display (CRT35), a light shows (system's switchboard 42) or the like, its output content is stored in the sensing equipment, and time of measuring and at interval, or other useful information etc. is also exported by it when last output processing.
In other words; detected signal not only exists as above-mentioned prediction signal; and the protection equipment (as lightning arrester) of working as distribution wire moves; or temporary transient noise (as the impact that is caused by lightning) or various signal noise have been arranged, so a kind of situation of can not determine earth fault omen zone just takes place.Therefore, also to export other useful information.
(1) meteorology when detecting (thunder, during typhoon etc.);
(2) corresponding zone in short-term in detected one to several times, and in long-time as the regional detection of earth fault omen less than;
(3) earth fault omen district moves (automobile noise) or the like.Thus, the operator can determine easily that it is different with the earth fault omen.
In other words, be " finding near same position, in basic interval, to take place several times ".
This just is easy to manually determine taken place the earth fault omen on distribution wire, and the output monitoring grounding fault omen needed result in zone.To this, belong to examples of applications of the present invention, as, when being detected N time, the same area produces an output, or the output of generation when once above of detected zone.
And then, by the feature of the every part of storage distribution wire in determining device 3, can fill the output of above-mentioned useful information.
Be exactly by adding
(a) might with the tree contact area demonstration;
(b) salt causes the badly damaged zone;
(c) controller switching equipment (pole transformer, pole switch cut off switch or the like);
(d) size of distribution wire;
(e) earth fault takes place or the like, and the note that is added can be added to the output of CRT41 etc., and can help the operator to determine.
In the future make sensing equipment can utilize this information (said AT function is arranged) to belong to simple example of the present invention automatically.
In addition, the invention is not restricted to predict the earth fault omen, determine its zone and with its output, also be effective according to its result (Tathagata is from the indication of main website 30) to the control below the distribution wire.
One of them is near detected earth fault omen point, in the transmission distribution wire a normal cut-off point is arranged.The advantage that is possessed is thus, can determine detected earth fault omen point more particularly, and when just earth fault having taken place before inspection earthing fault omen part, can reduce the scope because the feeder line that circuit breaker trip caused cuts off the power supply.Figure 16 represents an original distribution wire, and wherein switch SW-1～SW-12 is by bus C
1Power supply, and switch SW 20～SW30 is by bus B
2Power supply.Normal cut-off point is a switch SW-0, and it is with feeder line F
1And F
2Separately.Here supposition, switch SW has defencive function, and a sensor is adorned in each unit.Distance between these switches is generally 1～3KM.In addition, between these switches, be provided with a large amount of hand switches.Therefore, both made by determining at this point slight earth fault to have taken place from a signal of the sensor of installing on the switch SW-10, and when needs are known particular location, still needed to search around this point, to this, actual consideration is between SW-9～SW-11.Now, closure and SW-10 disconnect if normal cut-off point has been transferred to SW-10(SW-0), and suppose to have monitored the maximal value of slight earth fault next pulse signal at the SW-9 place, then can be described as between SW-10 and SW-9 and (do not comprise SW-9 or SW-10), and the earth fault omen zone that presents can be reduced.Have again,, just can prevent at SW-10 to the interrupt run between the SW-0 if after this earth fault taken place immediately.So, when having determined earth fault omen zone by this way, all be effective then to distribution wires all in this replaced zone or various device.To this; change normal cut-off point (in case the switch of closed at present normal cut-off point; and open the switch of proximity transducer 10) can temporarily cause making distribution system to form loop, so, just need this loop situation is restricted to the short as far as possible time for the protection purpose.Concrete grammar has:
(1) accredits the operations staff in the position of at present normal cut-off point and proximity transducer 10, all installed switch in this position respectively and when interkniting, can realize " normal cut-off point closure " → " switch of proximity transducer 10 disconnects " rapidly by radio channel;
(2) if switch by distant place control (with cable system or carrier system), then switches normal cut-off point from operation station (steel side's controlling center), still, these operations are carried out according to operations staff's decision at that time.At this moment because the change of normal cut-off point causes changing the control situation of system, and need carry out according to the situation of holding load current in the every part of distribution wire, and will consider whether load is changeable.Consider this point,, and related to load distribution if system has constituted all switches as the control of an automatic power distribution system distant place, the changeable processing of loading, work program or the like then can be automatically performed by resulting records.To this, when the normal cut-off point of change was carried out loop control, main idea of the present invention reduces the loop control time with it irrelevant, therefore, except pointing out a purpose relevant with the present invention, no longer narration.
More than illustrate with the example of zero phase voltage as zero phase signals, still self-evident, equally can with Zero-phase current.
The table I
Mains frequency component high fdrequency component
Almost constant aperiodicity changes when the earth fault sign
Occur may shortening at interval to earth fault omen conversion little change,
Duration may extend
Big variation is recurred when earth fault
Claims (6)
1, the system of a kind of definite line of electric force earth fault omen position, its formation be by:
A plurality of sensors that multiple spot is provided with on line of electric force are used to detect the zero phase signals in the premises, and monitor in each zero phase signals, and monitor the pulse signal that comprises in each zero phase signals;
A sensing equipment is used for determining having the earth fault omen near above-mentioned a plurality of sensors have indicated the installation position of the peaked sensor of pulse signal;
A signal transmitting apparatus that is arranged between a plurality of sensors and the said determination equipment is used to transmit the pulse signal that is obtained by a plurality of sensors.
2, a kind of system of the definite line of electric force earth fault omen position according to claim 1, it is characterized in that: the above-mentioned the sensor that is used for detecting in a three-phase power line zero phase signals comprises one by a capacitor and the series circuit that resistance is formed, be arranged between each phase and ground of three-phase power line, and a terminal that is arranged between this capacitor and resistance is used for output signal.
3, a kind of system of the definite line of electric force earth fault omen position according to claim 1, it is further characterized in that: be equiped with switch near a plurality of sensors of zero phase signals in detecting line of electric force;
The said determination device comprises according to the amplitude of a plurality of pulse signals to be determined and the system of output power line earth fault omen position, and produces the device of the operation signal of above-mentioned switch by signal transmitting apparatus, and
Above-mentioned a plurality of sensor has the device in response to above-mentioned each switch of manipulation signal of each switch that receives respectively.
4, according to the system of definite line of electric force earth fault omen position of claim 3, it is characterized in that: the pulse signal that comprises in the zero phase signals that this system responses is monitored in line of electric force, the earth fault omen of output power line or its position, and also export with causing and the relevant out of Memory of pulse signal occurs.
5, a kind of use is according to the method for the system of definite line of electric force earth fault omen position of claim 3, it is characterized in that: the amplitude of the pulse signal that monitoring comprises in multiple spot zero phase signals on line of electric force, when having determined its position, disconnect switch, and electric power is conducted to line of electric force at the two ends that separate by above-mentioned switch near earth fault omen position corresponding to above-mentioned amplitude.
6, a kind of method of determining the system of line of electric force earth fault omen position according to claim 3 of using, it is characterized in that: when pulse signal has been determined earth fault omen position in the zero phase signals that comprises in response to multiple spot in line of electric force, replace this position neighbouring line of electric force and electrical equipment.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP217366/89 | 1989-08-25 | ||
| JP1217366A JP3039936B2 (en) | 1989-08-25 | 1989-08-25 | Power line degradation determination method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1049761A CN1049761A (en) | 1991-03-06 |
| CN1017829B true CN1017829B (en) | 1992-08-12 |
Family
ID=16703051
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN90107791A Expired CN1017829B (en) | 1989-08-25 | 1990-08-25 | Method and apparatus for determining deterioration of electric power line |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP3039936B2 (en) |
| KR (1) | KR100238895B1 (en) |
| CN (1) | CN1017829B (en) |
| DE (1) | DE4026428C2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100418195B1 (en) * | 2001-07-05 | 2004-02-11 | 주식회사 우리기술 | Apparatus and method for multi-testing insulation of power cables |
| KR100719138B1 (en) | 2007-03-15 | 2007-05-18 | 주식회사 젤파워 | Method for fault diagnosing of receiving and distributing electricity equipment |
| JP2015073237A (en) * | 2013-10-04 | 2015-04-16 | 株式会社東芝 | Communication system and communication device |
| KR101762505B1 (en) | 2015-09-14 | 2017-07-28 | 아주대학교산학협력단 | Apparatus for cable inspection |
| CN110673024B (en) * | 2019-09-10 | 2022-05-13 | 国网浙江省电力有限公司嘉兴供电公司 | High-voltage circuit breaker fault early warning method based on power Internet of things |
| CN110705038B (en) * | 2019-09-10 | 2023-09-26 | 国网浙江省电力有限公司嘉兴供电公司 | High-voltage circuit breaker life cycle assessment and fault early warning method |
| JP2021081398A (en) * | 2019-11-22 | 2021-05-27 | パナソニックＩｐマネジメント株式会社 | Abnormality detection system, distribution board, abnormality detection method, and program |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54155442A (en) * | 1978-05-29 | 1979-12-07 | Nissin Electric Co Ltd | Insulation deterioration detector for electric appliances |
| JPS5544976A (en) * | 1978-09-27 | 1980-03-29 | Sumitomo Electric Ind Ltd | Trouble shooter for power cable |
| JPS5720779A (en) * | 1980-07-11 | 1982-02-03 | Matsushita Electric Ind Co Ltd | Image display unit |
| JPS5720778A (en) * | 1980-07-11 | 1982-02-03 | Matsushita Electric Ind Co Ltd | Image display unit |
| JPS5915870A (en) * | 1982-07-16 | 1984-01-26 | Mitsubishi Electric Corp | Apparatus for measuring partial discharge |
| DE3636367C2 (en) * | 1986-10-25 | 1995-07-13 | Licentia Gmbh | Method and device for determining the distance and direction of earth faults in isolated and compensated power networks |
| GB8727490D0 (en) * | 1987-11-24 | 1987-12-23 | Nat Res Dev | Detecting faults in transmission circuits |
-
1989
- 1989-08-25 JP JP1217366A patent/JP3039936B2/en not_active Expired - Fee Related
-
1990
- 1990-08-21 DE DE4026428A patent/DE4026428C2/en not_active Expired - Fee Related
- 1990-08-24 KR KR1019900013092A patent/KR100238895B1/en not_active IP Right Cessation
- 1990-08-25 CN CN90107791A patent/CN1017829B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| KR100238895B1 (en) | 2000-01-15 |
| JP3039936B2 (en) | 2000-05-08 |
| CN1049761A (en) | 1991-03-06 |
| DE4026428A1 (en) | 1991-02-28 |
| JPH0382326A (en) | 1991-04-08 |
| KR910005059A (en) | 1991-03-29 |
| DE4026428C2 (en) | 1994-10-13 |
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