CN102788934A - Method and device for finding line ground fault point - Google Patents
Method and device for finding line ground fault point Download PDFInfo
- Publication number
- CN102788934A CN102788934A CN2012102587675A CN201210258767A CN102788934A CN 102788934 A CN102788934 A CN 102788934A CN 2012102587675 A CN2012102587675 A CN 2012102587675A CN 201210258767 A CN201210258767 A CN 201210258767A CN 102788934 A CN102788934 A CN 102788934A
- Authority
- CN
- China
- Prior art keywords
- signal
- current signal
- circuit
- current
- measured
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Images
Landscapes
- Locating Faults (AREA)
Abstract
The invention provides a method for finding a line ground fault point. The line ground fault point is found through a signal transmitter and a signal receiver, wherein the signal transmitter is used for enabling a line to be detected to generate transmitting current signals. The method for finding the line ground fault point comprises the steps that: a) the signal receiver generates a reference voltage signal with the same frequency as a transmitting voltage signal; b) the signal receiver conducts datum point setting; and c) the signal receiver calculates corrected phase phi am' of the transmitting current signal of a detection point relative to the set datum point, and according to the corrected phase phi am', indicating the direction of the transmitting current signal of the detection point. The invention additionally provides a corresponding device. By generating the reference voltage signal with the same frequency as the transmitting voltage signal through the signal receiver to obtain the direction of the transmitting current signal in the line to be detected, the ground fault point on the line to be detected can be accurately and rapidly positioned.
Description
Technical field
The present invention relates to the wireline inspection field, more particularly, relate to a kind of method and device of searching line-to-ground fault point.
Background technology
When earth fault occurring in the circuit, need search, the fault location point.Usually adopt that following method is searched, the fault location point: exchange or the voltage signal of direct current to sending between circuit to be measured and the ground through a sender unit; Because line-to-ground resistance and the existence of distributed capacitance over the ground; Circuit to be measured can produce and search current signal accordingly; Use a signal receiver to search current signal along wireline inspection to be measured simultaneously, the place that occurs cataclysm in the intensity of searching current signal or phase place is earth fault.
Owing to search current signal is to flow out from the sender unit output terminal, and the circuit to be measured of flowing through flows out from earth fault at last; Flow back to sender unit by ground; Therefore signal receiver is searched sense of current as if indicating, and then can find earth fault fast along searching sense of current.Through this mode, when searching the earth fault of complicated netted circuit, work efficiency can significantly improve.
At present, when searching line-to-ground fault point, the method for the detection of leaks current signal direction that adopts usually has following several kinds:
(1) AC signal method: the voltage signal (reference signal) that between circuit to be measured and ground, sends the alternation of lower frequency by sender unit; Promptly produce in the circuit to be measured and search current signal accordingly; This frequency of searching current signal is identical with voltage signal (reference signal), but phase place difference to some extent.Sender unit is simultaneously also through wired, wireless or sent the modulated signal of the upper frequency after being modulated by reference signal and high-frequency signal to signal receiver by circuit to be measured self.Signal receiver is searched current signal along treating that line inspection road follows the tracks of to detect; With receiving through wired, wireless or by circuit to be measured self; The modulated signal that reception is sent by sender unit, its demodulation restored reference signal after, compare with the phase place of detected Leakage Current signal.If phase differential is near 0 °, then the signal receiver indicated direction is with to search the current signal direction identical; If phase differential is near 180 °, then the signal receiver indicated direction is with to search current signal in the opposite direction.
The shortcoming of this method is to need sender unit to intercom mutually through wired or wireless mode with signal receiver.When adopting wired mode to communicate, need special-purpose telecommunication cable to connect sender unit and signal receiver, and search in the earth fault point process, telecommunication cable moves around in tow, and is extremely inconvenient; When adopting communication, sender unit and signal receiver possibly be positioned at the different location, and the centre has barrier such as wall and intercepts mutually; Radio communication is often interrupted, and because signal receiver is a portable set, generally adopts powered battery; Radio communication can cause the power consumption meeting significantly to increase; After battery was full of electricity, the electric weight of battery storage exhausted very soon in the use, and the working time of equipment is very limited.If utilization is looked into the survey line road and itself is transmitted carrier signal; When having bigger undesired signal on, the circuit faint when Leakage Current, the carrier signal decay of upper frequency is very big, causes phase measurement error bigger; Be difficult to correctly indicate the Leakage Current direction, can't drop into practical application.
(2) direct current signaling: send d. c. voltage signal by sender unit to circuit to be measured and make circuit generation to be measured search current signal accordingly, follow the tracks of to receive by signal receiver along circuit to be measured then and search current signal.Direct current signal itself is directive, and signal receiver utilizes the directivity of direct current signal, thus the direction of indication Leakage Current.
The shortcoming of this method is: first; Because the zero point drift of acceptor circuit is difficult to detect faint Leakage Current signal, during existence is bigger on therefore faint when Leakage Current, the circuit undesired signal; It is bigger to detect error, can't correctly indicate the direction of Leakage Current.The second, this method only is adapted at the not troubleshooting of charged working line, when the charged work of circuit, owing to itself working current is arranged on the circuit, can't carry out troubleshooting.
(3) direct current signaling of band zero compensation: the similar direct current signaling of this method; But sender unit produces low-frequency square-wave signal (searching signal); Sender unit, signal receiver be through wired, wireless or communicated by circuit to be measured self mode, when square-wave signal low level (being no signal output), manually or automatically with signal receiver zero setting; When the square-wave signal high level, the detection of searching signal.
Though this method can be avoided the zero point drift of signal receiver circuit; But when having the undesired signal of complicated alternating current-direct current on the circuit; Can't eliminate the influence of undesired signal; Thereby on, circuit faint when Leakage Current during bigger undesired signal, this method error is bigger, can't correctly indicate the direction of searching current signal.In addition, this method also needs sender unit and signal receiver through intercoming mutually through wired or wireless mode.When adopting wired mode to communicate, need special-purpose telecommunication cable to connect sender unit and signal receiver, and search in the earth fault point process, telecommunication cable moves around in tow, and is extremely inconvenient; When adopting the wireless mode communication mode, sender unit and signal receiver possibly be positioned at the different location, and the centre has barrier such as wall and intercepts mutually; Radio communication can often be interrupted, and because signal receiver is a portable set, generally adopts powered battery; Radio communication can cause the power consumption meeting significantly to increase; After battery was full of electricity, the electric weight of battery storage can exhaust very soon in the use, and the working time of equipment is very limited.If utilize and to be looked into the survey line road and itself transmit carrier signal, when having bigger undesired signal on, the circuit faint when Leakage Current, the carrier signal decay of upper frequency is very big, can't drop into practical application.
In sum; Can detect method of searching earth fault and the device of searching direction of current at present; Use extremely inconvenient; Be not easy to indicate exactly the direction of searching current signal, especially for searching searching of the very faint high resistance earthing fault point of electric current, and the searching of the on-the-spot earth fault that has a stronger interference.
Summary of the invention
The technical matters that the present invention will solve is, can't accurately indicate the problem of searching the current signal direction in searching to above-mentioned earth fault, and a kind of method and device of searching line-to-ground fault point is provided.
The technical scheme that the present invention solves the problems of the technologies described above is; A kind of method of searching line-to-ground fault point is provided; Be grounded the trouble spot through sender unit and signal receiver and search, wherein said sender unit is used for applying the transmission voltage signal that frequency is f0 to circuit to be measured and sends current signal so that circuit to be measured produces; May further comprise the steps:
(a) said signal receiver produces a reference voltage signal with said transmission voltage signal same frequency;
(b) said signal receiver carries out the reference point setting according to transmission current signal in the said circuit to be measured and said reference voltage signal;
(c) said signal receiver carries out synchronized sampling to transmission current signal, the reference voltage signal of Ka Cedianchu; Calculate the modified phase φ am ' of the transmission current signal of this Ka Cedianchu with respect to the reference point that is provided with; And, indicate this Ka Cedianchu to send the direction of current signal according to said modified phase φ am '.
In method of searching line-to-ground fault point of the present invention, said signal receiver sends the current signal direction through the direction signs indication that is arranged on the direction signs on the signal receiver and on display screen, shows, said step (b) comprising:
(b1) said signal receiver synchronized sampling detects the transmission current signal and the reference voltage signal of datum on the circuit to be measured, said reference point be send in the circuit to be measured the current signal direction known a bit and the direction signs that on the said signal receiver of this datum, are provided with identical with the direction of transmission current signal in the said circuit to be measured;
(b2) said signal receiver calculates and stores the phase differential of said transmission current signal and reference voltage signal when receiving the reference point setting command: Δ φ b=φ a0-φ b0; Wherein φ a0 is the phase place of the signal content of f0 for the frequency of sending current signal, and φ b0 is that the frequency of reference voltage signal is the phase place of the signal content of f0.
In method of searching line-to-ground fault point of the present invention; Also comprise in the said step (b2): when receiving the reference point setting command, calculating the frequency of sending current signal is the amplitude I0 of the signal content of f0, and stores this amplitude I0 for sending the reference value I b:Ib=I0 of current signal size.
In method of searching line-to-ground fault point of the present invention, comprise in the said step (c); The frequency of calculating said Ka Cedianchu transmission current signal is the amplitude Im of the signal content of f0, and calculates the relative amplitude that this place sends current signal: Im '=Im/Ib * 100%.
In method of searching line-to-ground fault point of the present invention; In the said step (c); The modified phase φ am ' at the transmission current signal relative datum point place of said Ka Cedianchu=φ am-φ bm-Δ φ b; Wherein φ am is the phase place of the signal content of f0 for the frequency of sending current signal, and φ bm is that the frequency of reference voltage signal is the phase place of the signal content of f0.
In method of searching line-to-ground fault point of the present invention, in the said step (c): when-90 °＜φ am '＜90 °, the display screen of said signal receiver shows that sending direction of current is " forward "; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °, the display screen of said signal receiver shows that sending direction of current is " oppositely ".
The present invention also provides a kind of device of searching line-to-ground fault point, comprises sender unit and signal receiver, and wherein said sender unit is used for applying the transmission voltage signal that frequency is f0 to circuit to be measured and sends current signal so that circuit to be measured produces; Said signal receiver comprises that signal generating unit, current detecting unit, analysis and processing unit, direction indicating member and reference point are provided with the unit; Wherein: said signal generating unit is used to produce a reference voltage signal with said transmission voltage signal same frequency; Said current detecting unit is used for detecting the transmission current signal of circuit to be measured; Said analysis and processing unit is used for said transmission current signal and reference voltage signal are carried out synchronized sampling, and calculates the modified phase φ am ' that sends current signal relative datum point place; Said direction indicating member is used for the direction of sending current signal according to said modified phase φ am ' indication circuit to be measured; Said reference point is provided with the unit, is used for carrying out the reference point setting according to the transmission current signal and the said reference voltage signal of said circuit to be measured.
In the device of searching line-to-ground fault point of the present invention; Said direction indicating member comprises direction signs that are arranged on the signal receiver and the direction signs that on display screen, show; Said analysis and processing unit also is used to calculate the transmission current signal of datum on the circuit to be measured and the phase difference φ b=φ a0-φ b0 of reference voltage signal; Wherein φ a0 is the phase place of the signal content of f0 for the frequency of sending current signal; φ b0 is that the frequency of reference voltage signal is the phase place of the signal content of f0, and said reference point is provided with the unit and instruction is set the time stores said analysis and processing unit and calculate the transmission current signal that obtains and the phase difference φ b of reference voltage signal receiving.
In the device of searching line-to-ground fault point of the present invention; The frequency that said analysis and processing unit also is used for sending current signal in computer card measuring point place be f0 signal content amplitude Im and with respect to the relative amplitude Im ' of reference point, said reference point is provided with the unit and also is used to be stored in and receives analysis and processing unit when instruction is set and calculate the amplitude I0 that obtains for sending the reference value I b:Ib=I0 of current signal size.
In the device of searching line-to-ground fault point of the present invention; The modified phase φ am ' at said transmission current signal relative datum point place=φ am-φ bm-Δ φ b; Wherein φ am is the phase place of the signal content of f0 for the frequency of sending current signal, and φ bm is that the frequency of reference voltage signal is the phase place of the signal content of f0; When-90 °＜φ am '＜90 °, the display screen of said signal receiver shows that sending direction of current is " forward "; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °, the display screen of said signal receiver shows that sending direction of current is " oppositely ".
The method and apparatus of searching line-to-ground fault point of the present invention; Produce a reference voltage signal with transmission voltage signal same frequency through signal receiver is inner; And to send current signal, the reference voltage signal carries out synchronized sampling, analysis; Confirm diverse location sends current signal on the circuit the modified phase with respect to reference point, direction and relative amplitude; Thereby confirm the direction of the transmission current signal in the circuit, to locate the earth fault on the circuit to be measured accurately and rapidly.Especially; Among the present invention; Signal receiver only utilizes the phase relation of the reference voltage signal that sends current signal on the circuit to be measured and self produce; Differentiate each position transmission sense of current on the circuit to be measured, thereby locate earth fault fast, and need not to adopt any wired or wireless communication method to communicate by letter with sender unit.
Description of drawings
Fig. 1 is the synoptic diagram that the present invention searches the application scenarios of line-to-ground fault point apparatus.
Fig. 2 is the synoptic diagram of signal receiver embodiment among Fig. 1.
Fig. 3 is the synoptic diagram of the transmission current signal located of A among Fig. 1, B, 3 of D.
Fig. 4 is the synoptic diagram of phase place of the transmission current signal at A among Fig. 1, B, C, D each point place.
Fig. 5 is the schematic flow sheet that the present invention searches the method embodiment of line-to-ground fault point.
Embodiment
In order to make the object of the invention, technical scheme and advantage clearer,, the present invention is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
Like Fig. 1, shown in 2; The device of searching line-to-ground fault point of the present invention comprises sender unit 1 and signal receiver 2; Wherein sender unit 1 applies the transmission voltage signal that frequency is f0 (for example sine wave, square wave, triangular wave) through connecting line 3 between circuit to be measured and ground, sends current signal (because existence of stake resistance and distributed capacitance) so that circuit to be measured produces.Particularly, the positive output end of above-mentioned sender unit 1 is connected to circuit to be measured, negative output terminal ground connection.The transmission current signal that signal receiver 2 detects on the above-mentioned circuit to be measured; Simultaneously it innerly produces a reference voltage signal with transmission voltage signal same frequency; This signal receiver 2 is through carrying out synchronized sampling, analysis to transmission current signal, reference voltage signal; Confirm that diverse location sends phase place, direction and the amplitude of current signal on the circuit to be measured, thereby locate the earth fault on the circuit to be measured accurately and rapidly.
Analysis and processing unit 23 is used for transmission current signal and reference voltage signal that current detecting unit 22 obtains are carried out synchronized sampling, and the modified phase φ am ' at the transmission current signal relative datum point place at computer card measuring point place and relative amplitude Im '.Particularly; The transmission current signal and the reference voltage signal of 23 pairs of synchronized samplings of this analysis and processing unit; Adopt respectively and pay sharp leaf algorithm, calculating the frequency of sending current signal is the phase am of the signal content of f0, and the frequency of calculating the reference voltage signal is the phase bm of the signal content of f0; And the datum of storage sends the phase difference φ b of current signal and reference voltage signal, and calculates the modified phase of transmission current signal at this moment in view of the above: φ am '=φ am-φ bm-Δ φ b.
Reference point is provided with unit 24 and is used for carrying out the reference point setting according to the transmission current signal and the said reference voltage signal of circuit to be measured.Particularly; This reference point be provided with unit 24 receive reference point when instruction (for example specific button is pressed) is set analysis and processing unit 23 calculate the parameter that obtains and store; Above-mentioned parameter comprises the phase difference φ b of datum transmission current signal and reference voltage signal; And datum sends the reference value I b of current signal size, and with this as the reference point parameter.
When the current sensor with pincerlike opening is fixed on 2 last times of signal receiver, above-mentioned direction indicating member 25 can be only to display screen output and transmission current signal actual flow to consistent direction signs, and need not direction signs to be set at the shell of signal receiver.
Using signal receiver 2 to carry out reference point when being provided with; Can select in the circuit to be measured to send that direction of current confirms a bit as reference point; For example the point of the E among Fig. 1 is (near the junction of sender unit 1 with circuit to be measured; Can confirm that the transmission direction of current is here pointed to other parts of circuit to be measured by the E point), or in the forward transportation outlet of sender unit (can confirm here transmission direction of current for pointing to circuit to be measured by sender unit 1).Behind selected reference point; The direction signs of direction indicating member 25 that make signal receiver 2 are with to send the current signal direction identical; Analysis and processing unit 23 is calculated the transmission current signal of this moment and the phase differential of reference voltage signal at this moment; Receiving reference point when instruction (for example specific button is pressed) is set; Reference point is provided with unit 24 inventory analysis processing units 23 and calculates the transmission current signal of acquisition and the phase differential of reference voltage signal: Δ φ b=φ a0-φ b0, and wherein φ a0 is that the frequency of the transmission current signal of datum is the phase place of the signal content of f0, φ b0 is that the frequency of corresponding reference voltage signal is the phase place of the signal content of f0.
It is the amplitude Im of the signal content of f0 that above-mentioned analysis and processing unit 23 also can be calculated the frequency of sending current signal, and calculates the relative amplitude that this place sends current signal: Im '=Im/Ib * 100%.And reference point is provided with unit 24 and also is stored in to receive and when instruction analysis and processing unit 23 is set calculates the amplitude I0 that obtains for sending the reference value I b:Ib=I0 of current signal size.
As shown in Figure 1, have earth fault C in the circuit to be measured, the trouble spot stake resistance is R, the distributed capacitance over the ground of both sides, trouble spot circuit equivalence respectively is C
1, C
2At first between circuit to be measured and ground, apply sinusoidal wave voltage signal: u through sender unit 1
0(t)=U
0* sin (2 π f
0T), because the existence of line-to-ground resistance and distributed capacitance produces sinusoidal wave current signal: the i of transmission
Am(t)=Iamsin (2 π f
0T+ φ am).
At circuit each point to be measured place, the amplitude Iam that sends current signal is different with phase am, as shown in Figure 3: at the A of circuit to be measured point, send current signal I
A=I
C1+ I
C2+ I
R, phase place is sent voltage signal φ in advance
AThe angle.At the B of circuit to be measured point, send current signal I
B=I
C2+ I
R, phase place is sent voltage signal φ in advance
BThe angle.At the D of circuit to be measured point, send current signal I
C=I
C2, phase place is sent voltage signal φ in advance
DThe angle.
In fact, the distributed capacitance over the ground of circuit all exists in whole circuit, and the variation of sending the current signal phase place in the actual track is as shown in Figure 4; Fig. 4 (b) sends current signal magnitude situation along circuit to be measured; Fig. 4 (c) sends current signal phase change situation along circuit to be measured, and among Fig. 4 (c), the phase place of sending current signal all is to be benchmark with reference point E place transmission current signal; Numerical value is leading for just representing, numerical value is that negative indication lags behind.
Method of application of searching the device of line-to-ground fault point of the present invention below is described.
At first the positive output end with sender unit 1 is connected to circuit to be measured, negative output terminal ground connection, and between circuit to be measured and ground, applying frequency is the transmission voltage signal of f0.
Signal receiver produces a reference voltage signal with transmission voltage signal same frequency.
Press " reference settings " button on the signal receiver 2, with this moment signal receiver the card measuring point as the reference point that sends current signal, calculate also the transmission current signal of storage datum and the phase differential of reference voltage signal: Δ φ b=φ a0-φ b0; Calculating the frequency of sending current signal is the amplitude I0 of the signal content of f0, and stores this amplitude I0 for sending the reference value I b:Ib=I0 of current signal size.
After the completion reference point is provided with, can block the modified phase φ am ' of the transmission current signal of any point on the survey circuit to be measured,, indicate this Ka Cedianchu to send the direction of current signal with according to said modified phase φ am ' with respect to reference point; The frequency of calculating this Ka Cedianchu transmission current signal is the relative amplitude of the signal content of f0: Im '=Im/Ib * 100%.
After the completion reference point is provided with, if block survey at reference point, then can obtain following result: send current signal modified phase φ am '=0, display screen shows that sending direction of current is " forward ", sends relative amplitude Im '=100% of current signal.
Again signal receiver 2 is stuck on the circuit to be measured more arbitrarily; Transmission current signal, the reference voltage signal at 2 pairs of these places of signal receiver carry out synchronized sampling; Adopt and pay sharp leaf algorithm; Calculating the frequency of sending current signal respectively is amplitude Im, the phase am of the signal content of f0, and the frequency of reference voltage signal is the phase bm of the signal content of f0, and calculates the modified phase that this Ka Cedianchu sends current signal: φ am '=φ am-φ bm-Δ φ b.Synchronous signal receiver 2 also can calculate the relative amplitude that this Ka Cedianchu sends current signal: Im '=Im/Ib * 100%.
Further judge that this Ka Cedianchu sends the direction of current signal: when-90 °≤φ am '≤90 °, show that the direction of sending current signal be " forward ", the direction signs of setting are identical on the direction that current signal is sent in expression and the signal receiver 2; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °, show that the direction of sending current signal be " oppositely ", the direction signs of setting are opposite on the direction of expression transmission current signal and the signal receiver 2.
Owing to send current signal is the positive output end outflow from sender unit 1; The circuit to be measured of flowing through, the earth fault from circuit to be measured flows out at last, flows back to sender unit 1 by ground again; Therefore signal receiver 2 is if can indicate the direction of sending current signal; Then along the direction of sending current signal, pointwise card volume can find earth fault fast.
After detecting modified phase φ am ', direction and the relative amplitude Im ' that sends the current signal signal on the circuit to be measured, can confirm earth fault easily according to circuit and knowledge:
Single-wire line: like Fig. 1, shown in Figure 3; Along the direction of sending current signal; Back before the earth fault C of circuit to be measured (B, D 2 points on the circuit to be measured in like Fig. 1, Fig. 3, the relative amplitude (being Im ') of sending current signal can diminish suddenly, and the modified phase of sending current signal simultaneously is at earth fault the most negative (in like Fig. 3 on the circuit to be measured C point); After earth fault (like D point on the circuit to be measured among Fig. 3); The modified phase of sending current signal can rise suddenly, according to this characteristic, can accurately locate earth fault.
Complicated netted circuit: judge according to following characteristics: sending current signal must be to flow out from sender unit 1 output terminal; The circuit to be measured of flowing through; Flow out from earth fault at last; Flow back to sender unit 1 by ground again, and the modified phase of sending current signal is the most negative in earth fault.Therefore; When running into branched line, should continue to look into and survey the branch road that the relative amplitude of sending current signal modified phase maximum, that send current signal is the most negative, the transmission current signal flows out, after branch road is confirmed; According to the survey method of looking into of single-wire line, determine earth fault at last again.
As shown in Figure 5; The present invention also provides a kind of method of searching line-to-ground fault point; It is grounded the trouble spot through sender unit and signal receiver and searches, and wherein sender unit is used for applying the transmission voltage signal that frequency is f0 so that circuit to be measured produces the transmission current signal to circuit to be measured.This method may further comprise the steps:
Step S51: signal receiver produces a reference voltage signal with transmission voltage signal same frequency.
Step S52: carry out the reference point setting according to transmission current signal and the reference voltage signal in datum in the circuit to be measured.
Step S53: transmission current signal, reference voltage signal that signal receiver is treated each Ka Cedianchu on the survey line road carry out synchronized sampling; The modified phase φ am ' at the transmission current signal relative datum point place at computer card measuring point place and relative amplitude Im ', and according to the direction of this Ka Cedianchu transmission current signal of modified phase φ am ' indication.
In said method; Signal receiver is provided with direction signs; On display screen, show direction signs; And step S52 can specifically comprise: when signal receiver receives the reference point setting command synchronized sampling detect datum on the circuit to be measured transmission current signal and reference voltage signal after; Calculate and store the phase differential that sends current signal and reference voltage signal: Δ φ b=φ a0-φ b0, wherein φ a0 is the phase place of the signal content of f0 for the frequency of sending current signal, φ b0 is that the frequency of reference voltage signal is the phase place of the signal content of f0.
Especially, when reference point was provided with, it was the amplitude I0 of the signal content of f0 that signal receiver also can calculate the frequency of sending current signal, and stored this amplitude I0 for sending the reference value I b:Ib=I0 of current signal size.Correspondingly, at Ka Cedianchu, the frequency that signal receiver also calculates this Ka Cedianchu transmission current signal is the amplitude Im of the signal content of f0, and calculates this place and send the relative amplitude of current signal with respect to datum: Im '=Im/Ib * 100%.
In the above-mentioned method of searching line-to-ground fault point; The modified phase φ am ' at the transmission current signal relative datum point place of Ka Cedianchu on the circuit to be measured among the step S53=φ am-φ bm-Δ φ b; Wherein φ am is the phase place of the signal content of f0 for the frequency of sending current signal, and φ bm is that the frequency of reference voltage signal is the phase place of the signal content of f0.Especially, when-90 °＜φ am '＜90 °, the display screen of said signal receiver shows that sending direction of current is " forward ", representes that the direction signs that are provided with on direction and the signal receiver of transmission current signal of this Ka Cedianchu are identical; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °; The display screen of said signal receiver shows that sending direction of current is " oppositely ", representes that the direction signs that are provided with on direction and the signal receiver of transmission current signal of this Ka Cedianchu are opposite.
The above; Be merely the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, any technician who is familiar with the present technique field is in the technical scope that the present invention discloses; The variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.
Claims (10)
1. method of searching line-to-ground fault point; Be grounded the trouble spot through sender unit and signal receiver and search, wherein said sender unit is used for applying the transmission voltage signal that frequency is f0 to circuit to be measured and sends current signal so that circuit to be measured produces; It is characterized in that: may further comprise the steps:
(a) said signal receiver produces a reference voltage signal with said transmission voltage signal same frequency;
(b) said signal receiver carries out the reference point setting according to transmission current signal in the said circuit to be measured and said reference voltage signal;
(c) said signal receiver carries out synchronized sampling to transmission current signal, the reference voltage signal of Ka Cedianchu; Calculate the modified phase φ am ' of the transmission current signal of this Ka Cedianchu with respect to the reference point that is provided with; And, indicate this Ka Cedianchu to send the direction of current signal according to said modified phase φ am '.
2. method of searching line-to-ground fault point according to claim 1; It is characterized in that: said signal receiver sends the current signal direction through the direction signs indication that is arranged on the direction signs on the signal receiver and on display screen, shows, said step (b) comprising:
(b1) said signal receiver synchronized sampling detects the transmission current signal and the reference voltage signal of datum on the circuit to be measured, said reference point be send in the circuit to be measured the current signal direction known a bit and the direction signs that on the said signal receiver of this datum, are provided with identical with the direction of transmission current signal in the said circuit to be measured;
(b2) said signal receiver calculates and stores the phase differential of said transmission current signal and reference voltage signal when receiving the reference point setting command: Δ φ b=φ a0-φ b0; Wherein φ a0 is the phase place of the signal content of f0 for the frequency of sending current signal, and φ b0 is that the frequency of reference voltage signal is the phase place of the signal content of f0.
3. method of searching line-to-ground fault point according to claim 2; It is characterized in that: also comprise in the said step (b2): when receiving the reference point setting command, calculating the frequency of sending current signal is the amplitude I0 of the signal content of f0, and stores this amplitude I0 for sending the reference value I b:Ib=I0 of current signal size.
4. method of searching line-to-ground fault point according to claim 3 is characterized in that: comprise in the said step (c); The frequency of calculating said Ka Cedianchu transmission current signal is the amplitude Im of the signal content of f0, and calculates the relative amplitude that this place sends current signal: Im '=Im/ Ib * 100%.
5. method of searching line-to-ground fault point according to claim 2; It is characterized in that: in the said step (c); The modified phase φ am ' at the transmission current signal relative datum point place of said Ka Cedianchu=φ am-φ bm-Δ φ b; Wherein φ am is the phase place of the signal content of f0 for the frequency of sending current signal, and φ bm is that the frequency of reference voltage signal is the phase place of the signal content of f0.
6. method of searching line-to-ground fault point according to claim 5 is characterized in that: in the said step (c): when-90 °＜φ am '＜90 °, the display screen of said signal receiver shows that sending direction of current is " forward "; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °, the display screen of said signal receiver shows that sending direction of current is " oppositely ".
7. a device of searching line-to-ground fault point comprises sender unit and signal receiver, and wherein said sender unit is used for applying the transmission voltage signal that frequency is f0 to circuit to be measured and sends current signal so that circuit to be measured produces; It is characterized in that: said signal receiver comprises that signal generating unit, current detecting unit, analysis and processing unit, direction indicating member and reference point are provided with the unit; Wherein: said signal generating unit is used to produce a reference voltage signal with said transmission voltage signal same frequency; Said current detecting unit is used for detecting the transmission current signal of circuit to be measured; Said analysis and processing unit is used for said transmission current signal and reference voltage signal are carried out synchronized sampling, and calculates the modified phase φ am ' that sends current signal relative datum point place; Said direction indicating member is used for the direction of sending current signal according to said modified phase φ am ' indication circuit to be measured; Said reference point is provided with the unit, is used for carrying out the reference point setting according to the transmission current signal and the said reference voltage signal of said circuit to be measured.
8. the device of searching line-to-ground fault point according to claim 7; It is characterized in that: said direction indicating member comprises direction signs that are arranged on the signal receiver and the direction signs that on display screen, show; Said analysis and processing unit also is used to calculate the transmission current signal of datum on the circuit to be measured and the phase difference φ b=φ a0-φ b0 of reference voltage signal; Wherein φ a0 is the phase place of the signal content of f0 for the frequency of sending current signal; φ b0 is that the frequency of reference voltage signal is the phase place of the signal content of f0, and said reference point is provided with the unit and instruction is set the time stores said analysis and processing unit and calculate the transmission current signal that obtains and the phase difference φ b of reference voltage signal receiving.
9. the device of searching line-to-ground fault point according to claim 8; It is characterized in that: the frequency that said analysis and processing unit also is used for sending current signal in computer card measuring point place be f0 signal content amplitude Im and with respect to the relative amplitude Im ' of reference point, said reference point is provided with the unit and also is used to be stored in and receives analysis and processing unit when instruction is set and calculate the amplitude I0 that obtains for sending the reference value I b:Ib=I0 of current signal size.
10. the device of searching line-to-ground fault point according to claim 8; It is characterized in that: the modified phase φ am ' at said transmission current signal relative datum point place=φ am-φ bm-Δ φ b; Wherein φ am is the phase place of the signal content of f0 for the frequency of sending current signal, and φ bm is that the frequency of reference voltage signal is the phase place of the signal content of f0; When-90 °＜φ am '＜90 °, the display screen of said signal receiver shows that sending direction of current is " forward "; When 90 °≤φ am '≤180 ° or-180 °≤φ am '≤-90 °, the display screen of said signal receiver shows that sending direction of current is " oppositely ".
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210258767.5A CN102788934B (en) | 2012-07-25 | 2012-07-25 | Search method and the device of line-to-ground fault point |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210258767.5A CN102788934B (en) | 2012-07-25 | 2012-07-25 | Search method and the device of line-to-ground fault point |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102788934A true CN102788934A (en) | 2012-11-21 |
| CN102788934B CN102788934B (en) | 2015-09-30 |
Family
ID=47154390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210258767.5A Active CN102788934B (en) | 2012-07-25 | 2012-07-25 | Search method and the device of line-to-ground fault point |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102788934B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104076249A (en) * | 2014-07-15 | 2014-10-01 | 国家电网公司 | Three-phase three-winding transformer one-phase ground fault coverage diagnostic method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02275373A (en) * | 1989-04-14 | 1990-11-09 | San'eisha Mfg Co Ltd | Fault direction discriminator for overhead distribution wire |
| CN1261671A (en) * | 1999-01-20 | 2000-08-02 | 东芝株式会社 | Fault locator using positive phase, sequence electricity quantity |
| CN2869879Y (en) * | 2006-01-05 | 2007-02-14 | 关兴虎 | Intelligent fault line-selection and positioning system |
| CN101666851A (en) * | 2009-06-05 | 2010-03-10 | 深圳市普禄科智能检测设备有限公司 | Insulation, voltage, grounding test and grounding finding device and use method thereof |
| CN202994956U (en) * | 2012-07-25 | 2013-06-12 | 深圳市普禄科智能检测设备有限公司 | Device of searching grounding fault point of circuit |
-
2012
- 2012-07-25 CN CN201210258767.5A patent/CN102788934B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02275373A (en) * | 1989-04-14 | 1990-11-09 | San'eisha Mfg Co Ltd | Fault direction discriminator for overhead distribution wire |
| CN1261671A (en) * | 1999-01-20 | 2000-08-02 | 东芝株式会社 | Fault locator using positive phase, sequence electricity quantity |
| CN2869879Y (en) * | 2006-01-05 | 2007-02-14 | 关兴虎 | Intelligent fault line-selection and positioning system |
| CN101666851A (en) * | 2009-06-05 | 2010-03-10 | 深圳市普禄科智能检测设备有限公司 | Insulation, voltage, grounding test and grounding finding device and use method thereof |
| CN202994956U (en) * | 2012-07-25 | 2013-06-12 | 深圳市普禄科智能检测设备有限公司 | Device of searching grounding fault point of circuit |
Non-Patent Citations (2)
| Title |
|---|
| 周江波: "输电线路故障分析及故障点查找", 《江西电力》 * |
| 王慧刚 等: "输电线路故障点的查找", 《山西电力》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104076249A (en) * | 2014-07-15 | 2014-10-01 | 国家电网公司 | Three-phase three-winding transformer one-phase ground fault coverage diagnostic method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102788934B (en) | 2015-09-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2019232858B2 (en) | Mobile electric leakage detection device and method | |
| CN103293443B (en) | A kind of distribution network overhead line Earth design method | |
| US9000778B2 (en) | Communication method for monitoring pipelines | |
| CN101358827B (en) | TEM detecting method for pipe wall thickness and intelligent detector for GBH pipe corrosion | |
| CN105259584A (en) | Water area electric prospecting system | |
| CN100504414C (en) | Built-in type low-voltage cable detecting device | |
| CN100430743C (en) | Directional and positioning testing device for fault of direct application type cable sheath | |
| CN105467274A (en) | Device for fault detection and positioning of single-phase grounding of power distribution network | |
| AU2016240434A1 (en) | Method and device for detecting buried metal using synchronous detection method | |
| CN104515515A (en) | Radio compass tester | |
| CN101603982A (en) | Consider the distributed method for collecting zero-sequence current of load variations | |
| CN102841143A (en) | Method for detecting corrosion of grounded grid circular steel bar based on lateral loading of piezoelectric sensors | |
| CN202994956U (en) | Device of searching grounding fault point of circuit | |
| CN104360215A (en) | Detection device for multi-point earthing fault of small bus N600 | |
| CN102788934A (en) | Method and device for finding line ground fault point | |
| CN105005086A (en) | Searching and detection device for cable path | |
| CN102043085B (en) | Ultrahigh voltage power grid and current on-load detector | |
| CN204330953U (en) | Electric distribution network overhead wire singlephase earth fault searches instrument | |
| CN212808573U (en) | Circuit single-phase grounding detection system | |
| CN212808574U (en) | Circuit single-phase grounding detection tool | |
| CN110470950B (en) | Fault location method for power transmission line | |
| CN102901913B (en) | Partial discharge synchronous monitoring method for multiple electrical equipment of substation | |
| US20220075006A1 (en) | Mobile electric leakage detection device and method | |
| CN204142969U (en) | A kind of pipe and cable detector | |
| CN116203347A (en) | Line fault detection device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |