CN107422223B - A kind of method of distribution small current grounding fault positioning - Google Patents
A kind of method of distribution small current grounding fault positioning Download PDFInfo
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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
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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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
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- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
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Abstract
The present invention relates to a kind of methods of distributed small current grounding fault positioning, the following steps are included: step S1: distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except record zero-sequence current waveform after the starting of distribution terminal Sudden Changing Rate, while broadcasting the transient zero-sequence information that this terminal detects；Step S2: after terminal receives the transient zero-sequence information broadcasted on network, this terminal is inquired within effective time, whether Sudden Changing Rate starting record is had, if having, then comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, judge the zero-sequence current amplitude detected, if meeting entry condition, then start neighborhood detection program, enters step S3；Step S3: neighborhood detects program: utilizing transient zero-sequence current waveform analogue method, determines fault section.The present invention determines fault section using distributed algorithm using distribution terminal or two distant fault detectors.
Description
Technical field
The present invention relates to field of electric power automation is belonged to, more particularly to a kind of bar code reading method applied to POS terminal.
Background technique
China and Continental Europe power network neutral point are widely used earth-free or through grounding through arc mode.Due to connecing
The reason that earth-current is small, intermittent grounding fault ratio is high, the especially influence of arc suppression coil compensation electric current, conventional utilization work
The success rate of frequency zero-sequence current and harmonic signal fault line selection device is low (less than 60%).In the investment of recent development resistance with
And the method to system injection characteristic current signal, success rate are significantly improved, but investment is big, safety is poor, and is not suitable for
The instantaneity ground fault frequently occurred.The transient current amplitude that instant of failure generates is greatly (up to hundreds of amperes), not by extinguishing arc
Coil influences are able to solve the low problem of line selection and location sensitivity, but due to not going deep into fault transient understanding, early stage proposes temporary
State method (first half-wave method) criterion is unreasonable, and do not succeed application.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of method of distributed small current grounding fault positioning, using matching
Electric terminals use the distributed algorithm of peer-to-peer communications, determine small current grounding fault fault section.
The present invention is realized using following scheme: a kind of method of distribution small current grounding fault positioning, including following step
It is rapid:
Step S1: distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except note after the starting of distribution terminal Sudden Changing Rate
Zero-sequence current waveform is recorded, while broadcasting the transient zero-sequence information that this terminal detects；
Step S2: after terminal receives the transient zero-sequence information broadcasted on network, this terminal is inquired within effective time, is
It is no to have Sudden Changing Rate starting record, if so, then comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, judges to detect
The zero-sequence current amplitude arrived starts neighborhood detection program, enters step S3 if meeting entry condition；
Step S3: neighborhood detects program: this terminal obtains adjacent end address, Xiang Suoyou adjacent end by network topology
The instruction for sending request transient zero-sequence current recorder data, it is similar to the transient zero-sequence current of adjacent end to calculate this terminal two-by-two
Coefficient determines fault section using transient zero-sequence current waveform analogue method.
Further, in the step S1 distribution terminal starting be specially the following steps are included:
Step S11: the selection of first starting distribution terminal:
Compare the amplitude of the collected transient zero-sequence current of distribution terminal corresponding to each test point, selects transient current width
It is worth distribution terminal of the maximum distribution terminal as first starting；
Step S12: the starting of distribution terminal:
It is directly accessed zero sequence current signal using each distribution terminal, transient zero-sequence current is directly sampled and is recorded
Wave；Start distribution terminal using the starting method of zero-sequence current Sudden Changing Rate.
Further, the entry condition of field detection program is in the step S2: starting the transient zero-sequence electricity of terminal
Flow the amplitude that amplitude is greater than other adjacent transient zero-sequence currents.
Further, in the step S11, the selection of first starting distribution terminal specifically:
After line failure, certain time interval T0Interior transient zero-sequence current amplitude calculation formula are as follows:
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；i(t)
It is the instantaneous value of transient zero-sequence current.
In the step S21, the starting of distribution terminal specifically:
Distribution terminal starts distribution terminal using the method for transient zero-sequence current Sudden Changing Rate, and its step are as follows:
Firstly, the threshold value I that setting Distributing Terminal Assembly startsst.Capacitor electricity between test point downstream line and the earth
The virtual value of stream is as threshold value, the threshold value I of distribution terminal startingstAre as follows:
Ist=KrelI0i,I0i=3 ω U0iC0i； (2)
In formula: KrelFor coefficient of reliability；I0iFor the virtual value of i sections of capacitance currents between downstream line and the earth；U0iFor
The virtual value of the residual voltage of test point i；C0iFor the capacitor between test point i downstream line and the earth；
Secondly, sampled signal is compared with the threshold value that device starts, judge whether the entry condition for meeting device；It will
Zero-sequence current sampled signal is compared with the threshold value that device starts in sampling window, if having 2 in 8 continuous sampled points
And the amplitude of the above sampled point is greater than threshold value, then distribution terminal starts and records fault message；Otherwise, distribution terminal will not open
It is dynamic, continue to sample transient current；
Finally, recording fault message after distribution terminal starting and doing the processing and calculating of next step.
Further, the starting of the field detection program specifically:
Distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except record zero sequence electricity after the starting of distribution terminal Sudden Changing Rate
It flows outside waveform, while broadcasting the transient zero-sequence information that this terminal detects；Wherein, it is opened when recording zero-sequence current waveform with Sudden Changing Rate
It moves as boundary, 5 totally 8 cycles, 128 points of every cycle after record preceding 3；The transient zero-sequence information includes the starting time, terminal address
With zero-sequence current amplitude；
After terminal receives the transient zero-sequence information of online broadcast, this terminal is inquired within effective time, if having mutation
Amount starting record, if so, comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, if the zero sequence that judgement detects
Current amplitude is maximum, then starts neighborhood detection program.
Further, in the step S3, the detecting step of field detection program specifically includes the following steps:
Step S31: the foundation of network topological information:
Static configuration after the starting of field program, first to the switch attribute and application network topological classification of distribution terminal；
Setting to distribution terminal starting querying condition；Network topology inquiry is carried out later and forms application network topological structure；
Step S32: the definition of distribution terminal data format:
After network topology starting, starting distribution terminal issues querying command to adjacent distribution terminal, and the distribution being queried is whole
Termination is returned to querying command by querying command, and query information includes: information, location information and the fault message for switching itself；
Step S33: the synchronous setting of data:
Signal is carried out using the method for translation data window to synchronize, and finds each line feed terminals acquisition transient state zero on faulty line
The initial time of sequence electric current judges that data are synchronous if initial time is consistent；
Step S34: failure criterion:
Query terminal return querying command after, start calculated in distribution terminal it is temporary between its terminal adjacent thereto
State zero-sequence current similarity factor, select the smallest section of transient zero-sequence current similarity factor for suspected malfunctions section and with threshold value phase
Compare, if transient zero-sequence current similarity factor is lower than threshold value, which is fault section；Otherwise, which is doubtful section.
Further, in the step S31, the foundation of network topological information specifically:
The switch attribute includes the self attributes and position attribution of power distribution network switch, and wherein self attributes are divided into power transformation
It stands outlet switch, block switch and end switch；The position attribution of switch is the position of the switch in a network, and is opened with this
Close the network address of adjacent power distribution network switch；Forming position applied topology needs to extract the switch attribute information of power distribution network switch
In position attribution information；Stream information is crossed as Intelligent terminal of distribution network querying triggering condition using what distribution terminal detected；
After starting terminal starting network topology inquiry, the distribution terminal adjacent to it issues the life of request zero-sequence current data
It enables, adjacent distribution terminal receives querying command and returns to the order of zero-sequence current data.
The switch attribute information that inquiry switchs according to the application network topology of its own from all power distribution stations received
Middle topology information required for extracting oneself, forms applied topology network.
Further, in the step S32, the definition of distribution terminal data format specifically:
Starting the querying command that distribution terminal issues is transient zero-sequence current information, and distribution terminal is constantly in zero sequence electricity
The sampling of stream and recording status continue to sample 5 cycles and stop sampling, with event after reaching distribution terminal entry condition
3 cycles before barrier, 128 points of every cycle constitute one group of data；After query terminal receives querying command, continue sampling 4
Cycle simultaneously stops sampling, and with 4 cycles before failure, 128 points of every cycle constitute one group of data.
Further, in the step S33, the synchronous setting of data:
Calculate the transient zero-sequence electricity that fault message used in transient zero-sequence current similarity factor is the acquisition of adjacent feeders terminal
Signal is flowed, the time of the transient zero-sequence current signal of 2 line feed terminals acquisition is required when calculating transient zero-sequence current similarity factor
It keeps synchronizing, signal is carried out using the method for translation data window and is synchronized, it is right to meet the calculating requirement of transient current similarity factor
In 2 transient zero-sequence current waveforms of line feed terminals acquisition, it is motionless first to fix one of waveform, by another transient zero-sequence
The data window of electric current translates, while seeking transient current amplitude, the phase of the point transient zero-sequence current of amplitude maximum according to formula (3)
Relationship number is also maximum, and initial time differs also just smaller, is then judged as at this time synchronous:
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；i(t)
It is the instantaneous value of transient zero-sequence current；
At this point, the similarity factor calculation formula of transient zero-sequence current are as follows:
In formula: ik(t) and ik+1(t) it is respectively transient zero-sequence current that adjacent feeders terminal detects；T is sample sequence；
N is total length of data；τ is the points of transient zero-sequence current translation, and the length that τ is arranged is 1ms~2ms.
Further, in the step S34, breakdown judge specifically:
On faulty line, fault point upstream is ipsilateral or downstream the is ipsilateral transient zero-sequence current wave between adjacent feeders terminal
Shape differs very little, and the transient zero-sequence current similarity factor of two waveforms is big, close to 1；Between the line feed terminals of fault point two sides
Transient zero-sequence current waveform differs greatly, and the transient zero-sequence current similarity factor of two waveforms is small, close to 0；From faulty line
When selecting the biggish line feed terminals of transient zero-sequence current amplitude, at least 3 line feed terminals are selected therefrom to start field detection
Program, line feed terminals are inquired using network topology, send request transient zero-sequence current order, quilt to adjacent line feed terminals respectively
The adjacent feeders terminal of inquiry receives querying command and returns to transient zero-sequence current information；After a while, it is collected into
After the transient zero-sequence current information of all adjacent feeders terminals, transient zero-sequence current phase of the terminal with adjacent end is calculated two-by-two
Like coefficient, is compared by calculating, therefrom select the smallest section of transient zero-sequence current similarity factor for suspected malfunctions section, then
Compared with the threshold value pre-set, if transient zero-sequence current similarity factor is less than threshold value, it is judged as fault section；It is no
Then, it is suspected malfunctions section, fault section or the doubtful section of failure is reported to main website.
Compared to the prior art, the invention has the following advantages:
1, distributed location method, does not need main website participation, and speed is fast.
2, the setting of terminal starting definite value is sensitive, prevents from failing to report.As long as there is a terminal starting, will search automatically adjacent
Terminal.
3, detection program in field transfers neighbor data using inquiry instruction, and the data utilized are comprehensive, using comparing waveform phase
Like the method for property, confidence level threshold values is set, prevents from reporting by mistake.
4, good to communication mode adaptability, it can be fiber optic communication, be also possible to other communication modes.
After singlephase earth fault occurs for route, it can timely find abort situation and timely handle, avoid to matching
Grid power system causes more serious loss.This method does not depend on main website, and locating speed is fast, and it is reliable to be remarkably improved power supply
Property.
Detailed description of the invention
Fig. 1 is the definition schematic diagram of information transmission time in the present invention.
Fig. 2 is the flow chart for starting detection program in field in the present invention.
Fig. 3 is that programme diagram is detected in field in the present invention.
Specific embodiment
The present invention will be further described with reference to the accompanying drawings and embodiments.
The present embodiment provides a kind of method of distributed small current grounding fault positioning, this method as shown in Fig. 2, include with
Lower step:
Step S1: distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except note after the starting of distribution terminal Sudden Changing Rate
Zero-sequence current waveform is recorded, while broadcasting the transient zero-sequence information that this terminal detects；
Step S2: after terminal receives the transient zero-sequence information broadcasted on network, this terminal is inquired within effective time, is
It is no to have Sudden Changing Rate starting record, if so, then comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, judges to detect
The zero-sequence current amplitude arrived starts neighborhood detection program, enters step S3 if meeting entry condition；
Step S3: neighborhood detects program: this terminal obtains adjacent end address, Xiang Suoyou adjacent end by network topology
The instruction for sending request transient zero-sequence current recorder data, it is similar to the transient zero-sequence current of adjacent end to calculate this terminal two-by-two
Coefficient determines fault section using transient zero-sequence current waveform analogue method.
In the present embodiment, in the step S1 distribution terminal starting be specially the following steps are included:
Step S11: the selection of first starting distribution terminal:
Compare the amplitude of the collected transient zero-sequence current of distribution terminal corresponding to each test point, selects transient current width
It is worth distribution terminal of the maximum distribution terminal as first starting；
Step S12: the starting of distribution terminal:
It is directly accessed zero sequence current signal using each distribution terminal, transient zero-sequence current is directly sampled and is recorded
Wave；Start distribution terminal using the starting method of zero-sequence current Sudden Changing Rate.
In the present embodiment, the entry condition of field detection program is in the step S2: starting the transient state zero of terminal
Sequence current amplitude is greater than the amplitude of other adjacent transient zero-sequence currents.
In the present embodiment, in the step S11, the selection of first starting distribution terminal specifically:
After line failure, certain time interval T0Interior transient zero-sequence current amplitude calculation formula are as follows:
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；i(t)
It is the instantaneous value of transient zero-sequence current.
In the step S21, the starting of distribution terminal specifically:
Distribution terminal starts distribution terminal using the method for transient zero-sequence current Sudden Changing Rate, and its step are as follows:
Firstly, the threshold value I that setting Distributing Terminal Assembly startsst.Capacitor electricity between test point downstream line and the earth
The virtual value of stream is as threshold value, the threshold value I of distribution terminal startingstAre as follows:
Ist=KrelI0i,I0i=3 ω U0iC0i； (2)
In formula: KrelFor coefficient of reliability；I0iFor the virtual value of i sections of capacitance currents between downstream line and the earth；U0iFor
The virtual value of the residual voltage of test point i；C0iFor the capacitor between test point i downstream line and the earth；
Secondly, sampled signal is compared with the threshold value that device starts, judge whether the entry condition for meeting device；It will
Zero-sequence current sampled signal is compared with the threshold value that device starts in sampling window, if having 2 in 8 continuous sampled points
And the amplitude of the above sampled point is greater than threshold value, then distribution terminal starts and records fault message；Otherwise, distribution terminal will not open
It is dynamic, continue to sample transient current；
Finally, recording fault message after distribution terminal starting and doing the processing and calculating of next step.
In the present embodiment, the starting of the field detection program specifically:
Distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except record zero sequence electricity after the starting of distribution terminal Sudden Changing Rate
It flows outside waveform, while broadcasting the transient zero-sequence information that this terminal detects；Wherein, it is opened when recording zero-sequence current waveform with Sudden Changing Rate
It moves as boundary, 5 totally 8 cycles, 128 points of every cycle after record preceding 3；The transient zero-sequence information includes the starting time, terminal address
With zero-sequence current amplitude；
After terminal receives the transient zero-sequence information of online broadcast, this terminal is inquired within effective time, if having mutation
Amount starting record, if so, comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, if the zero sequence that judgement detects
Current amplitude is maximum, then starts neighborhood detection program.
In the present embodiment, in the step S3, the field detection program obtains phase by network topology for this terminal
Adjacent terminal address, Xiang Suoyou adjacent end send request transient zero-sequence current recorder data instruction, calculate two-by-two this terminal with
The transient zero-sequence current similarity factor of adjacent end determines fault section, such as Fig. 3 using transient zero-sequence current waveform analogue method
It is shown, detecting step specifically includes the following steps:
Step S31: the foundation of network topological information:
Static configuration after the starting of field program, first to the switch attribute and application network topological classification of distribution terminal；
Setting to distribution terminal starting querying condition；Network topology inquiry is carried out later and forms application network topological structure；
Step S32: the definition of distribution terminal data format:
After network topology starting, starting distribution terminal issues querying command to adjacent distribution terminal, and the distribution being queried is whole
Termination is returned to querying command by querying command, and query information includes: information, location information and the fault message for switching itself；
Step S33: the synchronous setting of data:
In order to reduce error caused by time irreversibility, realize that signal is synchronous, with the method for translation data window to meet
The calculating requirement of transient current similarity factor.Realize that the synchronous emphasis of data is to find each line feed terminals acquisition on faulty line
The initial time of transient zero-sequence current is considered as data and is synchronized if initial time is consistent.Therefore, it is translated using data window
Method solves the problems, such as that data are nonsynchronous, i.e., first fixes the waveform of one of transient current, allows another transient current
Waveform is translated.The every translation of waveform once just calculates a related coefficient；Then a series of phase relation of transient currents is found out
Number, the maximum that takes absolute value is as transient current similarity factor；
Step S34: failure criterion:
Query terminal return querying command after, start calculated in distribution terminal it is temporary between its terminal adjacent thereto
State zero-sequence current similarity factor, select the smallest section of transient zero-sequence current similarity factor for suspected malfunctions section and with threshold value phase
Compare, if transient zero-sequence current similarity factor is lower than threshold value, which is fault section；Otherwise, which is doubtful section.
In the present embodiment, in the step S31, the foundation of network topological information specifically:
The switch attribute includes the self attributes and position attribution of power distribution network switch, and wherein self attributes are divided into power transformation
It stands outlet switch, block switch and end switch；The position attribution of switch is the position of the switch in a network, and is opened with this
Close the network address of adjacent power distribution network switch；Forming position applied topology needs to extract the switch attribute information of power distribution network switch
In position attribution information；Stream information is crossed as Intelligent terminal of distribution network querying triggering condition using what distribution terminal detected；
After starting terminal starting network topology inquiry, the distribution terminal adjacent to it issues the life of request zero-sequence current data
It enables, adjacent distribution terminal receives querying command and returns to the order of zero-sequence current data.
The switch attribute information that inquiry switchs according to the application network topology of its own from all power distribution stations received
Middle topology information required for extracting oneself, forms applied topology network.
In the present embodiment, in the step S32, the definition of distribution terminal data format specifically:
Starting the querying command that distribution terminal issues is transient zero-sequence current information, and distribution terminal is constantly in zero sequence electricity
The sampling of stream and recording status continue to sample 5 cycles and stop sampling, with event after reaching distribution terminal entry condition
3 cycles before barrier, 128 points of every cycle constitute one group of data；After query terminal receives querying command, continue sampling 4
Cycle simultaneously stops sampling, and with 4 cycles before failure, 128 points of every cycle constitute one group of data.
In the present embodiment, in the step S33, the synchronous setting of data:
Calculate the transient zero-sequence electricity that fault message used in transient zero-sequence current similarity factor is the acquisition of adjacent feeders terminal
Flow signal.The time of the transient zero-sequence current signal of 2 line feed terminals acquisition is required when calculating transient zero-sequence current similarity factor
It keeps synchronizing.In actual application, it is difficult to realize accurate synchronous that adjacent feeders terminal records transient current signal.In order to subtract
Error caused by few time irreversibility realizes that signal is synchronous, with the method for translation data window to meet the similar system of transient current
Several calculating requirements.Realize that the synchronous emphasis of data finds each line feed terminals acquisition transient zero-sequence current on faulty line
Initial time is considered as data and is synchronized if initial time is consistent.For 2 transient zero-sequence current waves of line feed terminals acquisition
Shape, first fixes that one of waveform is motionless, and the data window of another transient zero-sequence current is translated, while asking by formula (6)
Transient current amplitude is taken, the related coefficient of the point transient zero-sequence current of amplitude maximum is also maximum, and initial time difference is also got over
It is small, just approximately think to be synchronized at this time.
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；i(t)
It is the instantaneous value of transient zero-sequence current.
Therefore, failure initial time different band is overcome using the method for seeking transient current amplitude maximum in translation motion
The error come, ensure that the reliability of transient zero-sequence current similarity factor algorithm.At this point, the similarity factor meter of transient zero-sequence current
Calculate formula are as follows:
In formula: ik(t) and ik+1(t) it is respectively transient zero-sequence current that adjacent feeders terminal detects；T is sample sequence；
N is total length of data；τ is the points of transient zero-sequence current translation；Since adjacent feeders terminal transmission transient current information needs
It is delayed several milliseconds, therefore generally according to the precision of live adjacent feeders terminal clock synchronization, the length that τ is arranged is 1ms~2ms.
Because the transient zero-sequence current signal similarity degree of fault point two sides is lower, even if seeking maximum transient zero-sequence current phase
Like coefficient, it can also be lower than threshold value, still meet the principle of fault location.
After line feed terminals record the fault message of itself, the line feed terminals of Xiang Xianglin send the failure letter of oneself itself
Breath, during transmission, can generate certain delay.The passing time of information, including information transmission over networks time
With the processing time needed for transmitting-receiving both ends.Time delay in network is by transmission delay, propagation delay, processing delay and queuing delay group
At.As shown in Figure 1, total propagation delay time are as follows:
T=ta+tb+tc (5)
Wherein, ta is that transmission delay is also propagation delay time, when being required for line feed terminals or router transmission data frame
Between.It is counted from first bit for sending data frame, the last one bit to the frame is sent the required time.Hair
Send time delay=data frame length/channel width.Tb is that propagation delay is that electromagnetic wave propagates a certain distance in the channel and needs to spend
The time taken.Propagation delay=propagation rate of the channel length/electromagnetic wave on channel.Tc be processing delay refer to line feed terminals or
The time that router needs to spend when receiving grouping to Message processing handles the analysis including packet header, mentions from grouping
Take data portion, carry out error checking and correction or search routing appropriate etc..
As shown in Fig. 2, line feed terminals send the life of solicited message to adjacent line feed terminals when system operates normally
It enables, thus calculate, the delay time of each line feed terminals and adjacent feeders terminal, as shown in table 1:
The transmission delay time between 1 adjacent feeders terminal of table
According to the time-delay table of transmission time, the effective period of time of adjacent feeders terminal return can be calculated, if adjacent feedback
The delay time of line terminal is tmin, then t is takenminFront and back t0ms(t0≤ 10ms) in waveform.If when the delay of adjacent feeders terminal
Between be tmax, then to proparea 2t0Ms takes t backward0ms(t0≤ 10ms) in waveform.Reduce the biography of adjacent feeders terminal in this way
Defeated information content, calculation amount is small, and simple.When line fault, line feed terminals starting, the line feed terminals of Xiang Xianglin issue request letter
Breath order, adjacent line feed terminals will provide the fault message within effective time automatically, and this reduces fault message biographies
Defeated time delay.
In the present embodiment, in the step S34, breakdown judge specifically:
On faulty line, fault point upstream is ipsilateral or downstream the is ipsilateral transient zero-sequence current wave between adjacent feeders terminal
Shape differs very little, and the transient zero-sequence current similarity factor of two waveforms is big, close to 1；Between the line feed terminals of fault point two sides
Transient zero-sequence current waveform differs greatly, and the transient zero-sequence current similarity factor of two waveforms is small, close to 0；
When line failure, line feed terminals FTU is started using the Sudden Changing Rate of transient current, and line feed terminals are removed after starting
Outside record fault message, while broadcasting the transient zero-sequence current information oneself detected；
After other terminals on faulty line receive the transient zero-sequence current information broadcasted on network, will inquire is having
Whether there is Sudden Changing Rate activated in the effect time, if so, the transient zero-sequence current then broadcasted on comparing cell is detected with oneself
Transient zero-sequence current amplitude, the amplitude of temporary zero-sequence current is calculated by formula (1), if finding the transient zero-sequence oneself detected
Current amplitude is big, then will start neighborhood detection program, select the biggish feeder line of transient zero-sequence current amplitude whole from faulty line
When end, at least 3 line feed terminals are selected therefrom to start field detection program；
After the biggish line feed terminals of transient zero-sequence current amplitude (at least three) for selecting faulty line, the inspection of starting field
The flow chart of ranging sequence, field detection is as shown in Figure 3.Line feed terminals are inquired using network topology, whole to adjacent feeder line respectively
End sends request transient zero-sequence current order, and the adjacent feeders terminal being queried receives querying command and returns to transient zero-sequence current
Information；After a while, after being collected into the transient zero-sequence current information of all adjacent feeders terminals, the end is calculated two-by-two
The transient zero-sequence current similarity factor at end and adjacent end.Compared by calculating, therefrom selects transient zero-sequence current similarity factor
The smallest section is suspected malfunctions section, then compared with the threshold value pre-set, if transient zero-sequence current similarity factor
Less than threshold value, then it is judged as fault section；It otherwise, is suspected malfunctions section.Finally fault section or the doubtful section of failure
It is reported to main website.
In conclusion Fault Locating Method provided in this embodiment has following 4 remarkable advantages:
1) building of distribution terminal network topological information
The switch attribute of distribution terminal includes the self attributes and position attribution of power distribution network switch, and wherein self attributes are divided into
Substation's outlet switch, block switch and end switch；The position attribution of switch is the position of the switch in a network, Yi Jiyu
The network address of the adjacent power distribution network switch of the switch；Forming position applied topology needs to extract the switch attribute of power distribution network switch
Position attribution information in information；Stream information is crossed as Intelligent terminal of distribution network querying triggering using what distribution terminal detected
Item.
After starting terminal starting network topology inquiry, request zero-sequence current data will be issued to its adjacent distribution terminal
Order, adjacent distribution terminal receives querying command and returns to the order of zero-sequence current data.
The switch attribute information that inquiry switchs according to the application network topology of its own from all power distribution stations received
Middle topology information required for extracting oneself, forms applied topology network；
2) distribution terminal data format
Starting the querying command that distribution terminal issues is transient zero-sequence current information.Distribution terminal is constantly in zero sequence electricity
The sampling of stream and recording status continue to sample 5 cycles and stop sampling, with event after reaching distribution terminal entry condition
3 cycles (128 points of every cycle) before barrier constitute one group of data.After query terminal receives querying command, continue sampling 4
Cycle simultaneously stops sampling, and constitutes one group of data with 4 cycles (128 points of every cycle) before failure.
3) method of data synchronization
In order to reduce error caused by time irreversibility, realize that signal is synchronous, with the method for translation data window to meet
The calculating requirement of transient current similarity factor.Realize that the synchronous emphasis of data is to find each line feed terminals acquisition on faulty line
The initial time of transient zero-sequence current is considered as data and is synchronized if initial time is consistent.Therefore, it is translated using data window
Method solves the problems, such as that data are nonsynchronous, i.e., first fixes the waveform of one of transient current, allows another transient current
Waveform is translated.The every translation of waveform once just calculates a related coefficient；Then a series of phase relation of transient currents is found out
Number, the maximum that then takes absolute value is as transient current similarity factor.
4) failure criterion
After query terminal returns to querying command, by formula (4), to calculate it in distribution terminal adjacent thereto starting
Transient zero-sequence current similarity factor between terminal selects the smallest section of transient zero-sequence current similarity factor for suspected malfunctions area
Duan Bingyu threshold value compares, if transient zero-sequence current similarity factor is lower than threshold value, which is fault section；Otherwise, the area
Section is doubtful section.The fault section or suspected malfunctions section that detect finally are reported to main website, main website carry out failure every
From and perfect restoring electricity for section.The predetermined threshold level of transient zero-sequence current waveform similarity factor is empirical value, can generally be set
Between 0.5~0.8.
The foregoing is merely presently preferred embodiments of the present invention, all equivalent changes done according to scope of the present invention patent with
Modification, is all covered by the present invention.
Claims (9)
1. a kind of method of distribution small current grounding fault positioning, it is characterised in that: the following steps are included:
Step S1: distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except record zero after the starting of distribution terminal Sudden Changing Rate
Sequence current waveform, while broadcasting the transient zero-sequence information that this terminal detects；
Step S2: after terminal receives the transient zero-sequence information broadcasted on network, this terminal is inquired within effective time, if having
Sudden Changing Rate starting record judges to detect if so, then comparing cell transient zero-sequence current and local transient zero-sequence current amplitude
Zero-sequence current amplitude starts neighborhood detection program, enters step S3 if meeting entry condition；
Step S3: neighborhood detects program: this terminal obtains adjacent end address by network topology, and Xiang Suoyou adjacent end is sent
The instruction for requesting transient zero-sequence current recorder data, calculates this terminal system similar to the transient zero-sequence current of adjacent end two-by-two
Number, using transient zero-sequence current waveform analogue method, determines fault section；
Wherein, in the step S1 distribution terminal starting be specially the following steps are included:
Step S11: the selection of first starting distribution terminal:
Compare the amplitude of the collected transient zero-sequence current of distribution terminal corresponding to each test point, selects transient current amplitude most
Distribution terminal of the big distribution terminal as first starting；
Step S12: the starting of distribution terminal:
It is directly accessed zero sequence current signal using each distribution terminal, transient zero-sequence current is directly sampled and carries out recording；Benefit
Start distribution terminal with the starting method of zero-sequence current Sudden Changing Rate.
2. a kind of method of distributed small current grounding fault positioning according to claim 1, it is characterised in that: including with
Lower step: the entry condition of field detection program is in the step S2: the transient zero-sequence current amplitude for starting terminal is greater than
The amplitude of other adjacent transient zero-sequence currents.
3. a kind of method of distributed small current grounding fault positioning according to claim 1, it is characterised in that:
In the step S11, the selection of first starting distribution terminal specifically:
After line failure, certain time interval T0Interior transient zero-sequence current amplitude calculation formula are as follows:
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；I (t) is transient state
The instantaneous value of zero-sequence current；
In the step S12, the starting of distribution terminal specifically:
Distribution terminal starts distribution terminal using the method for transient zero-sequence current Sudden Changing Rate, and its step are as follows:
Firstly, the threshold value I that setting Distributing Terminal Assembly startsst, capacitance current between test point downstream line and the earth
Virtual value is as threshold value, the threshold value I of distribution terminal startingstAre as follows:
Ist=KrelI0i,I0i=3 ω U0iC0i； (2)
In formula: KrelFor coefficient of reliability；I0iFor the virtual value of i sections of capacitance currents between downstream line and the earth；U0iFor test point
The virtual value of the residual voltage of i；C0iFor the capacitor between test point i downstream line and the earth；
Secondly, sampled signal is compared with the threshold value that device starts, judge whether the entry condition for meeting device；It will sampling
Zero-sequence current sampled signal is compared with the threshold value that device starts in window, if having in 8 continuous sampled points 2 and with
The amplitude of up-sampling point is greater than threshold value, then distribution terminal starts and records fault message；Otherwise, distribution terminal not will start, after
It is continuous that transient current is sampled；
Finally, recording fault message after distribution terminal starting and doing the processing and calculating of next step.
4. a kind of method of distributed small current grounding fault positioning according to claim 2, it is characterised in that:
The starting of the field detection program specifically:
Distribution terminal is started using the Sudden Changing Rate of transient zero-sequence current, except record zero-sequence current wave after the starting of distribution terminal Sudden Changing Rate
Outside shape, while broadcasting the transient zero-sequence information that this terminal detects；Wherein, it is with Sudden Changing Rate starting when recording zero-sequence current waveform
Boundary, 5 totally 8 cycles after record preceding 3,128 points of every cycle；The transient zero-sequence information includes the starting time, terminal address and zero
Sequence current amplitude；
After terminal receives the transient zero-sequence information of online broadcast, this terminal is inquired within effective time, if having Sudden Changing Rate to open
Dynamic record, if so, comparing cell transient zero-sequence current and local transient zero-sequence current amplitude, if the zero-sequence current that judgement detects
Amplitude maximum then starts neighborhood detection program.
5. a kind of method of distributed small current grounding fault positioning according to claim 1, it is characterised in that:
In the step S3, the detecting step of neighborhood detection program specifically includes the following steps:
Step S31: the foundation of network topological information:
Static configuration after the starting of neighborhood program, first to the switch attribute and application network topological classification of distribution terminal；To matching
The setting of electric terminals starting querying condition；Network topology inquiry is carried out later and forms application network topological structure；
Step S32: the definition of distribution terminal data format:
After network topology starting, starting distribution terminal issues querying command to adjacent distribution terminal, and the distribution terminal being queried connects
By querying command, and querying command is returned to, query information includes: information, location information and the fault message for switching itself；
Step S33: the synchronous setting of data:
Signal is carried out using the method for translation data window to synchronize, and finds each line feed terminals acquisition transient zero-sequence electricity on faulty line
The initial time of stream judges that data are synchronous if initial time is consistent；
Step S34: failure criterion:
After query terminal returns to querying command, starting the transient state zero calculated between its terminal adjacent thereto in distribution terminal
Sequence electric current similarity factor selects the smallest section of transient zero-sequence current similarity factor for suspected malfunctions section and compared with threshold value
Compared with if transient zero-sequence current similarity factor is lower than threshold value, which is fault section；Otherwise, which is doubtful section.
6. a kind of method of distributed small current grounding fault positioning according to claim 5, it is characterised in that:
In the step S31, the foundation of network topological information specifically:
The switch attribute includes the self attributes and position attribution of power distribution network switch, and wherein self attributes are divided into substation and go out
Wiretap, block switch and end switch；The position attribution of switch be the position of the switch in a network, and with the switch phase
The network address of adjacent power distribution network switch；Forming position applied topology needs to extract in the switch attribute information of power distribution network switch
Position attribution information；Stream information is crossed as Intelligent terminal of distribution network querying triggering condition using what distribution terminal detected；
After starting terminal starting network topology inquiry, the distribution terminal adjacent to it issues the order of request zero-sequence current data,
Adjacent distribution terminal receives querying command and returns to the order of zero-sequence current data；
Inquiry mentions from the switch attribute information that all power distribution stations received switch according to the application network topology of its own
It is derived from oneself required topology information, forms applied topology network.
7. a kind of method of distributed small current grounding fault positioning according to claim 5, it is characterised in that:
In the step S32, the definition of distribution terminal data format specifically:
Starting the querying command that distribution terminal issues is transient zero-sequence current information, and distribution terminal is constantly in zero-sequence current
Sampling and recording status continue to sample 5 cycles and stop sampling, before failure after reaching distribution terminal entry condition
3 cycles, 128 points of every cycle constitute one group of data；After query terminal receives querying command, continue to sample 4 cycles
And stop sampling, with 4 cycles before failure, 128 points of every cycle constitute one group of data.
8. a kind of method of distributed small current grounding fault positioning according to claim 5, it is characterised in that:
In the step S33, the synchronous setting of data:
Calculate the transient zero-sequence current letter that fault message used in transient zero-sequence current similarity factor is the acquisition of adjacent feeders terminal
Number, require the time of the transient zero-sequence current signal of 2 line feed terminals acquisition to keep when calculating transient zero-sequence current similarity factor
It is synchronous, signal is carried out using the method for translation data window and is synchronized, to meet the calculating requirement of transient current similarity factor, for feedback
2 transient zero-sequence current waveforms of line terminal acquisition, it is motionless first to fix one of waveform, by another transient zero-sequence current
Data window translation, while seeking transient current amplitude according to formula (3), the phase relation of the point transient zero-sequence current of amplitude maximum
Number is also maximum, and initial time differs also just smaller, is then judged as at this time synchronous:
In formula: T0Selection should follow as often as possible retain transient signal and retain power frequency component as little as possible；I (t) is transient state
The instantaneous value of zero-sequence current；
At this point, the similarity factor calculation formula of transient zero-sequence current are as follows:
In formula: ik(t) and ik+1(t) it is respectively transient zero-sequence current that adjacent feeders terminal detects；T is sample sequence；N is number
According to total length；τ is the points of transient zero-sequence current translation, and the length that τ is arranged is 1ms~2ms.
9. a kind of method of distributed small current grounding fault positioning according to claim 5, it is characterised in that:
In the step S34, breakdown judge specifically:
On faulty line, fault point upstream is ipsilateral or downstream the is ipsilateral transient zero-sequence current waveform phase between adjacent feeders terminal
The transient zero-sequence current similarity factor of poor very little, two waveforms is big, close to 1；Transient state between the line feed terminals of fault point two sides
Zero-sequence current waveform differs greatly, and the transient zero-sequence current similarity factor of two waveforms is small, close to 0；It is selected from faulty line
When the biggish line feed terminals of transient zero-sequence current amplitude, at least 3 line feed terminals are selected therefrom to start field detection program,
Line feed terminals are inquired using network topology, are sent request transient zero-sequence current order to adjacent line feed terminals respectively, are queried
Adjacent feeders terminal receive and querying command and return to transient zero-sequence current information；After a while, it is collected into all
After the transient zero-sequence current information of adjacent feeders terminal, terminal system similar to the transient zero-sequence current of adjacent end is calculated two-by-two
Number is compared by calculating, therefrom selects the smallest section of transient zero-sequence current similarity factor for suspected malfunctions section, then and in advance
The threshold value first set compares, if transient zero-sequence current similarity factor is less than threshold value, is judged as fault section；Otherwise, it is
Fault section or the doubtful section of failure are reported to main website by suspected malfunctions section.
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| CN108254657B (en) * | 2018-03-28 | 2019-11-26 | 山东大学 | Power distribution network section with low-current ground faults localization method based on Study of Transient Energy |
| CN109541394A (en) * | 2018-11-21 | 2019-03-29 | 杭州电力设备制造有限公司 | A kind of method for locating single-phase ground fault of active distribution network, apparatus and system |
| CN109298288B (en) * | 2018-11-29 | 2019-11-08 | 中国矿业大学 | The distribution network failure section accurate positioning method of wide area zero-sequence current distributed intelligence |
| CN109387748A (en) * | 2018-12-21 | 2019-02-26 | 云南电网有限责任公司电力科学研究院 | A kind of power distribution network distribution small current grounding fault localization method and device |
| CN110596530B (en) * | 2019-09-06 | 2022-01-25 | 国网山东省电力公司寿光市供电公司 | Low-current ground fault line selection method |
| CN110736899B (en) * | 2019-11-25 | 2022-07-12 | 深圳供电局有限公司 | Small current grounding fault positioning method and system, monitoring device, equipment and medium |
| CN111007359A (en) * | 2019-12-26 | 2020-04-14 | 积成电子股份有限公司 | Power distribution network single-phase earth fault identification starting method and system |
| CN111413589B (en) * | 2020-04-02 | 2022-03-11 | 山东理工大学 | Power distribution network single-phase short circuit fault positioning method based on grey target decision |
| CN112485598A (en) * | 2020-12-04 | 2021-03-12 | 国网北京市电力公司 | Small current grounding fault positioning method combining waveform correlation and amplitude characteristics |
| CN113030651B (en) * | 2021-03-31 | 2023-03-14 | 国网上海市电力公司 | Method for positioning impact surge current |
| CN113484688B (en) * | 2021-07-22 | 2023-03-31 | 云南电网有限责任公司昆明供电局 | Power distribution network fault studying and judging method and system based on feeder line current sudden reduction degree |
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