CN107436394A - A kind of local ground fault detection method, device and system - Google Patents

A kind of local ground fault detection method, device and system Download PDF

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Publication number
CN107436394A
CN107436394A CN201610378751.6A CN201610378751A CN107436394A CN 107436394 A CN107436394 A CN 107436394A CN 201610378751 A CN201610378751 A CN 201610378751A CN 107436394 A CN107436394 A CN 107436394A
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earth
current
mrow
msub
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田京涛
田广宁
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田京涛
田广宁
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08Locating faults in cables, transmission lines, or networks
    • G01R31/081Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08Locating faults in cables, transmission lines, or networks
    • G01R31/088Aspects of digital computing

Abstract

A region delimited in power distribution network, when earth fault is not present in the region, region is to there was only capacitive component in earth-current;When there is earth fault in the regional extent, region causes region anomalous variation occur to earth-current to occurring resistive component in earth-current.The region for detecting the region judges that the region whether there is earth fault to earth-current, zoning to the size and Orientation of resistive component in earth-current.Or when earth fault occurs in power distribution network, artificial three phase-to-ground voltages for adjusting power distribution network, the region in the region is detected to earth-current and region to the situation of change of the resistive component of earth-current, judges that the region whether there is earth fault.Power distribution network is divided into multiple regions, when earth fault occurs in power distribution network, for whether there is earth fault in each region decision region, it is possible to achieve the zone location of the earth fault of power distribution network.

Description

A kind of local ground fault detection method, device and system
Technical field
The present invention relates to the fault detect of power distribution network local ground and distribution net work earthing fault zone location.
Background technology
With the increase of power distribution network capacity, the application of isolated neutral system gradually decreases, and the substitute is neutral point through disappearing Arc coil earthed system and Neutral Point Through Low Resistance system.It can be reduced and flowed through using neutral by arc extinction coil grounding mode The electric current of earth fault, reduce singlephase earth fault and develop into the possibility of phase fault, but add earthing wire-selecting The difficulty of positioning, earth fault is mainly searched using bracing wire method at present, often to spend even ten a few houres a few houres could be every From fault section, CSAT is reduced, while bring sale of electricity to lose.Neutral Point Through Low Resistance system is directed to metallicity Earth fault can realize selective tripping operation, but for high resistance earthing fault, cause relay fail because fault current is small, this When flow through the fault current that ground connection becomes and still exist, may cause to bypass the immediate leadership and jump main transformer low-pressure side switch, cause large-area power-cuts.With Various new energy (photovoltaic, wind-powered electricity generation etc.) access power distribution network, power distribution network is changed into power network from single supply Radial network, The difficulty of distribution net work earthing fault positioning is further increased, the problem does not solve this and made the most of the advantage not only bad for DG, right yet DG popularization adversely affects.Earthing wire-selecting orientation problem has turned into be improved power distribution network power supply quality, reduces unplanned power failure Time, a bottleneck for reducing power distribution network O&M cost, there is an urgent need to more accurate, more effective earthing wire-selecting localization method.
The content of the invention
It is an object of the invention to provide a kind of power distribution network local ground fault detection method, detection means, can sentence online A disconnected region whether there is earth fault.
The present invention also provides a kind of power distribution network local ground fault detection system, and power distribution network is divided into multiple areas by the system Domain, earth fault is judged whether respectively for each region, the region that earth fault be present is found out, is grounded failure Zone location.
To achieve these goals, power distribution network local ground fault detection method of the invention is as follows:
A region delimited in power distribution network, an equipment or one section of circuit can be only included in the region, also with bag Include connected and some adjacent equipment and some sections of circuits;
The region in the region is detected to earth-current using current sensing meansDetection zone is to earth-currentMethod It is:1. detection flows into whole electric currents in the region, these electric currents are added according to the direction vector inside inflow region and obtained Region is to earth-current2. whole electric currents that the earth is flowed into from the region are detected, by these electric currents according to the direction for flowing into the earth Vector addition obtains region to earth-current
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector With that is,:Wherein region is to earth-current resistive componentIt is three phase region to earth-current resistive componentVector, i.e.,:
Region is to earth-current capacitive componentIt is three phase region to earth-current capacitive componentVector, I.e.:
Region is to earth-current resistive componentDirectly related with earth fault, region is to earth-current resistive componentIt can reflect Flow through the size of the fault current of earth fault;
During power distribution network has earth fault, if earth fault is not present in the region, region is hindered earth-current Property componentVery little,Region is to earth-currentEqual to region to earth-current capacitive componentI.e.If the area When domain has earth fault, region is to earth-current resistive componentAbnormal increase is will appear from, also results in region to earth-current Abnormal increase is will appear from, region is to earth-currentWith region to earth-current resistive componentRelative to residual voltagePhase difference Also will change;The region obtained using detection is to earth-currentZoning is to earth-current resistive componentAccording to region To earth-current resistive componentSize and/or walking direction described in region whether there is earth fault;
During power distribution network has earth fault, the artificial phase-to-ground voltage of adjustment region three can be passed throughThe resistive component of the region to earth-current in earth fault region be present in increaseWiden and earth fault be present Resistive component of the region to earth-current between region and other normal regionsToo small gap, improves according to region to earth-current Resistive componentSize and/or walking direction described in region whether there is earth fault method effect;
During power distribution network has earth fault, three phase-to-ground voltages of power distribution network can also be artificially adjustedThe region for making to have earth fault region is to earth-currentWith region to earth-current resistive componentOccur Change, according to region to earth-currentAnd/or region is to earth-current resistive componentSituation of change, whether judge the region Earth fault be present.
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region three in the region relatively susceptance BEA、BEB、BEC
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith the phase-to-ground voltage of region threeUsing region to earth-current capacitive componentThe phase-to-ground voltage of region threeAnd region Three relatively susceptance BEA、BEB、BECBetween relation:
The region in the region is calculated to earth-current capacitive componentAccording to region to earth-currentRegion holds to earth-current Property componentWith region to earth-current resistive componentBetween relation:
Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge described in Region whether there is earth fault;
If the phase-to-ground voltage of region threeChange, region is to earth-current resistive componentWill hair Changing;Can be taking human as the phase-to-ground voltage of adjustment region threeThe region in earth fault region be present in increase To the resistive component of earth-currentWiden and region be present between earth fault region and other normal regions to the resistive of earth-current ComponentThe gap of size, improve the effect that detection has earth fault region;
Three phase-to-ground voltages of artificial adjustment power distribution networkThe region for artificially changing each region is electric over the ground Fluid resistance componentSize, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed; So can also be according to the region in the region to earth-current resistive componentThe size of change judges that the region whether there is Earth fault.
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region in the region total susceptance B over the groundE (BE=BEA+BEB+BEC);
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltage
Utilize region residual voltageWith region total susceptance B over the groundECapacitive component of the zoning to earth-current
According to region to earth-currentCapacitive component of the region to earth-currentAnd region is between earth-current resistive component Relation:
Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge described in Region whether there is earth fault;
If region residual voltageChange, region is to earth-current resistive componentIt will change;Can be taking human as Adjustment region residual voltageThe resistive component of the region to earth-current in earth fault region be present in increaseWiden in the presence of ground connection Resistive component of the region to earth-current between fault zone and other normal regionsThe gap of size, improve detection and ground connection be present The effect of fault zone;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed;So can also according to institute The region in region is stated to earth-current resistive componentThe size of change judges that the region whether there is earth fault.
For the region, when earth fault occurs in power distribution network, artificial three phase-to-ground voltages for adjusting power distribution networkThe region residual voltage detected before record adjustment voltageWith region to earth-currentRecord adjustment electricity The region residual voltage detected after pressureWith region to earth-current
It is to earth-current by the region after adjustment voltageConvert for adjustment voltage before region residual voltageIt is right The reduced value answered
The region after adjustment voltage is calculated to earth-current reduced valueWith the region before adjustment voltage to earth-current's Difference
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector With:
If earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, region is to earth-current Equal to region to earth-current capacitive componentI.e.:
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, capacitive point of the region to earth-current AmountWith region residual voltageBetween linear relationship be present:
If the region is not present earth fault, and the region three in the region relatively susceptance BEA、BEB、BECIt is Symmetrically, the region after the adjustment voltage in the region is to earth-current reduced valueWith the region before adjustment voltage to earth-currentShould be equal, i.e.,:
If the region has earth fault, region is to earth-current resistive componentAddition makeWithNo longer It is equal,Also just it is no longer equal to 0;Size can be with reflecting regional to earth-current resistive componentSize, can be with According to region current differential over the groundSize judge that the region whether there is earth fault.
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive component Size not only with region residual voltageSize it is relevant, also with region residual voltageDirection it is relevant, region is electric over the ground The capacitive component of streamWith region residual voltageBetween not necessarily or linear relationship, i.e.,:
According to region current differential over the groundSize judge that the region just increases with the presence or absence of the method for earth fault Uncertain factor is added;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, capacitive point of the region to earth-current AmountWith region residual voltageBetween basic or linear relationship;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, region pair The capacitive component of earth-currentSize to region to earth-currentSize influence it is little;
If meeting the two conditions, capacitive component that can be according to region to earth-currentWith region residual voltageIt Between linear relationship be present to handle, still can be according to region current differential over the groundSize whether judge the region Earth fault be present.
For the region, if earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, Region is to earth-currentEqual to region to earth-current capacitive componentI.e.:
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-currentAdvanced area Domain residual voltage
If earth fault occurs in the region, the region region is to earth-current resistive componentRegion is electric over the ground StreamIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector:
Because region is to earth-current resistive componentAddition, make region to earth-currentWith region residual voltageBetween Phase difference change, region is to earth-currentAdvanced region residual voltageRelation no longer set up;
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltage's Phase difference θ, it can judge that the region whether there is earth fault according to the value of phase difference θ;
Can be taking human as the adjustment phase-to-ground voltage of power distribution network three, the region that change has earth fault region is resistive to earth-current ComponentMake region to earth-currentWith region residual voltagePhase difference θ farther away from " region is to earth-currentAdvanced area Domain residual voltage" relation, so as to more accurately judge to have the region of earth fault.
The region can also be directed to, when earth fault occurs in power distribution network, the three of artificial adjustment power distribution network are relatively electric PressureRegion before record adjustment voltage is to earth-currentWith region residual voltagePhase difference θ1With The region of the detection after voltage is adjusted to earth-currentWith region residual voltagePhase difference θ2, calculate the change of phase difference Δ θ=θ21If the region of affiliated area is to earth-currentWith region residual voltagePhase difference variation delta θ compared with Greatly, it can determine whether that the region has earth fault;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, " region is to earth-currentAdvanced region Residual voltage" relation with regard to invalid, still, if the region three in the region relatively susceptance BEA、BEB、BECIt is not right Title degree is not serious, can be approximately considered that " region is to earth-currentAdvanced region residual voltage" relation still set up , still can be according to region to earth-currentWith region residual voltageThe size of phase difference θ or the change of phase difference sentence The disconnected region whether there is earth fault.
During defined area, reduce regional extent in equipment quantity and/or reduce regional extent in circuit length, reduce The relatively susceptance B of region threeEA、BEB、BEC, by the region in regional extent to earth-current capacitive componentControl the model in very little In enclosing;
When earth fault occurs in power distribution network, the region in the region is detected to earth-current
When earth fault is not present in the region, no Regional Economy three-phase voltage-to-groundHow to become Change, region is to earth-current capacitive componentOr very little, and in the absence of earth fault region region to resistive point of earth-current AmountBe approximately equal to 0, thus in the absence of earth fault region region to earth-currentVery little;
When there is earth fault in the region, the region in the region is to earth-current resistive componentIncrease, the area The region in domain is to earth-currentIt will increase therewith, region is to earth-currentSize can be with reflecting regional to earth-current resistive componentSize;Can be according to region to earth-currentSize judge that the region whether there is earth fault;
The region pair that earth fault region be present can be increased by artificially adjusting the method for the phase-to-ground voltage of power distribution network three Earth-current resistive componentRegion be present between earth fault region and other normal regions to earth-current resistive component in increasing Gap, so as to more accurately judge to have the region of earth fault;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed, and earth fault region be present Region to earth-currentAlso will have greatly changed;So can also be according to the region in the region to earth-currentChange Size judge that the region whether there is earth fault.
The region in the region is detected to earth-currentWith region residual voltageBy region to earth-currentIt is decomposed into flat Row is in region residual voltageParallel componentWith perpendicular to region residual voltageVertical component
Region is to earth-current resistive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith it is parallel In region residual voltageParallel component
Region is to earth-current capacitive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith it is parallel In region residual voltageParallel component
Region is to earth-currentIt is region to earth-current resistive componentTwo components and region to earth-current capacitive componentTwo components sum;
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-current capacitive componentThe residual voltage in the advanced regionThis time domain current parallel component over the ground With region to earth-current capacitive componentIt is unrelated, only with region to earth-current resistive componentIt is relevant, and region is put down to earth-current Row componentWith region to earth-current resistive componentProportional relation be present, i.e.,:If (region pair Earth-current resistive componentWith the residual voltage in regionBetween angle be θ, K=1/cos θ);So can be by the region Region current parallel component over the groundAs region to earth-current resistive componentConnect for judging that the region whether there is Earth fault;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive component With region residual voltageNo longer must be vertical relation, parallel component of the region to earth-current capacitive componentIt is no longer equal to 0,Because region is to the parallel component of earth-current capacitive componentAddition, earth-current is put down according to region Row componentJudge that the method for local ground failure increases uncertain factor;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, and region is to earth-current capacitive component Parallel component in residual voltage directionVery little;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, so area Domain is to parallel component of the earth-current capacitive component in residual voltage directionAlso very little;
If meeting the two conditions, region current parallel component over the ground can be approximately consideredEarth-current is hindered with region Property componentProportional relation be present, i.e.,:So still can be by the region in region current parallel point over the ground AmountAs region to earth-current resistive componentFor judging that the region whether there is earth fault;
The region pair that earth fault region be present can be increased by artificially adjusting the method for the phase-to-ground voltage of power distribution network three Earth-current resistive componentRegion current parallel component over the ground be present between earth fault region and other normal regions in increasing Gap, so as to more accurately judge to have the region of earth fault;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed, and earth fault region be present Region current parallel component over the groundAlso will have greatly changed;So can also be according to the region in the region over the ground Current parallel componentThe size of change judges that the region whether there is earth fault.
The power distribution network local ground failure detector of the present invention is as follows:
A region delimited in power distribution network, an equipment or one section of circuit can be only included in the region, can wrap Include connected and some adjacent equipment and some sections of circuits;
The power distribution network local ground failure detector can detect the region in the region to earth-currentIt is described to match somebody with somebody Grid ground fault detection device includes current sensing means, synchronous signal device, data acquisition device, data processing dress Put;The current sensing means supports the use with current transformer;
Whole electric currents acquisition region that the region is flowed into by detecting is as follows to the process of earth-current:
A, current sensing means is installed in each intersection in institute defined area and other regions;Described current sensing means The electric current detected both can be phase current or zero-sequence current;The current sensing means can detect the size of electric current; The current sensing means can also receive the synchronizing signal from synchronous signal device, and that detects electric current becomes positive zero crossing phase by negative For the time difference of synchronizing signal, or detection electric current is relative to the phase difference of synchronizing signal;
B, the data acquisition device can gather the current data of each current sensing means detection, and by the electric current number of collection According to sending data processing equipment;
C, the data processing equipment receives the current data from data acquisition device, by each electric current by flowing in region The direction vector in portion is added, can obtain the region in the region to the size of earth-current and region to earth-current relative to synchronous letter Number phase difference;
The whole electric currents for flowing into the earth from a region in power distribution network by detecting obtain process of the region to earth-current It is as follows:
A, between the equipment in the regional extent and the energized conductor and the earth of circuit with equipment being present, energized conductor Distribution capacity be present between equipment ground;Grounding body is being installed greatly on the ground, connected between grounding body by wire to equipment, Equipment with the earth equipotential, distribution between the distribution capacity i.e. electrical body and the earth between electrical body and equipment ground electricity Hold, the wire of equipment or line mutual-ground capacitor electric current by equipment between grounding body flows into the earth;Grounding body can only have One, it is possibility to have multiple;Equipment connecting wire between grounding body can there was only one, it is possibility to have more;
Current sensing means, the current detecting dress are installed in each bar connecting wire in equipment between grounding body b, Put the size of detectable electric current;The current sensing means can also receive the synchronizing signal from synchronous signal device, detection electricity Stream becomes time difference of the positive zero crossing relative to synchronizing signal, or detection electric current relative to the phase difference of synchronizing signal by negative;
C, the data acquisition device gathers the current data of each current sensing means detection, and by the current data of collection Send data processing equipment;
D, the data processing equipment receives the current data from data acquisition device, by each electric current by flowing to the earth Direction vector is added, and obtains phase of the region in the region to the size of earth-current and region to earth-current relative to synchronizing signal Potential difference;
The power distribution network local ground failure detector can utilize the region that detection obtains to earth-currentAccording to preceding The power distribution network local ground fault detection method stated, judge that the region whether there is earth fault.
The power distribution network local ground failure detector also includes voltage check device, the voltage check device and electricity Pressure transformer supports the use;The voltage check device can detect the size of voltage;The voltage check device can also receive Synchronizing signal from synchronous signal device, detection voltage become time difference of the positive zero crossing relative to synchronizing signal, or inspection by negative Survey phase difference of the voltage relative to synchronizing signal;
Detecting the method for the region residual voltage is:It is secondary using voltage check device detection threephase potential transformer The output of open-delta can obtain the data of residual voltage;The voltage check device can detect the size and zero of residual voltage Time difference or phase difference of the sequence voltage relative to synchronizing signal;The data acquisition device can gather the voltage check device inspection The voltage data of survey, and send the voltage data of collection to data processing equipment;The data processing equipment is received and adopted from data The voltage data of acquisition means, obtain the residual voltage in the region size and residual voltage relative to synchronizing signal phase Difference;
Detecting the method for three phase-to-ground voltage is:It is secondary defeated using voltage check device detection threephase potential transformer The data of three phase-to-ground voltages in the region can be obtained by going out voltage;The voltage check device can detect three phase-to-ground voltages The time difference or phase difference of size and three phase-to-ground voltages relative to synchronizing signal;The data acquisition device can gather the electricity The voltage data of detection means detection is pressed, and send the voltage data of collection to data processing equipment;The data processing equipment connects The voltage data from data acquisition device is received, the size of three phase-to-ground voltages of acquisition and three phase-to-ground voltages are relative to synchronous letter Number phase difference;
The method for detecting the region residual voltage can also be:Three phase-to-ground voltages are detected first with voltage check device Data, and be sent to data processing equipment by obtained voltage data is detected, data processing equipment presses three phase-to-ground voltages Direction vector relatively is added, can obtain residual voltage size and residual voltage relative to synchronizing signal phase difference;
The data processing equipment can utilize the region that detection obtains to earth-currentWith region residual voltageOr profit The region obtained with detection is to earth-currentWith the phase-to-ground voltage of region threeAccording to foregoing distribution barrier Domain earth-fault detecting method, judge that the region whether there is earth fault.
The methods of first passing through offline inspection or on-line checking or calculating, obtain the relatively susceptance B of region threeEA、BEB、BEC; And by the relatively susceptance B of region threeEA、BEB、BECIt is stored in data processing equipment;
When earth fault occurs in system, the power distribution network local ground failure detector can utilize region electric over the ground StreamThe phase-to-ground voltage of region threeWith the relatively susceptance B of region threeEA、BEB、BEC, according to foregoing distribution Web area earth-fault detecting method, judge that the region whether there is earth fault.
The methods of first passing through offline inspection or on-line checking or calculating, obtain region total susceptance B over the groundE;And by region Total susceptance B over the groundEIt is stored in data processing equipment;
When earth fault occurs in system, the region obtained using detection is to earth-currentRegion residual voltageAnd area Domain total susceptance B over the groundE, according to the power distribution network local ground fault detection method that right is foregoing, judge that the region whether there is Earth fault.
The synchronizing signal that the synchronous signal device is sent can be a controlled single pulse signal, can be one solid The pulse signal of fixed cycle, it can also be a sine wave signal;The synchronizing signal can be passed by wired, wireless mode It is defeated, it can also be transmitted by optical fiber;The synchronous signal device can utilize GPS second pulses generation synchronizing signal;
If the synchronizing signal is pulse signal, each voltage, current sensing means are all believed with the pulse of synchronization Number be used as time reference point, such as:Using GPS second pulses generation synchronizing signal, each voltage, current sensing means are with synchronization Pulse per second (PPS) as time reference, can be by each voltage, electricity in order to ensure to use the data in synchronization detection to participate in calculating Stream detection data stamp time tag;If the synchronizing signal is AC signal, each voltage, current sensing means are all with same One AC signal as reference signal, such as:Each voltage, current sensing means are all using A phase voltage signals as with reference to letter Number.
Voltage check device can be arranged in the regional extent, the voltage at some position inside detection zone; Voltage check device can be arranged on outside the regional extent, detect the position being connected with the region internal unit or circuit Voltage in some position outside regional extent, using the voltage inside the voltage zoning of region exterior, or directly by area The voltage in overseas portion is as the voltage inside region.
It is artificial to change the phase-to-ground voltage of region threeMethod include:Set between phase line and the earth Resistance, control the access of resistance between three-phase phase line and the earth respectively by three high-voltage switch gears, determined according to ground fault condition Closure wherein some switch;For neutral by arc extinction coil grounding system, the resistance in parallel with arc suppression coil is set, by high pressure The input of switch control parallel resistance;For neutral by arc extinction coil grounding system, the resistance connected with arc suppression coil is set, By the input and short circuit of high-voltage switch gear control series resistance;, can also be in extinguishing arc for neutral by arc extinction coil grounding system Secondary coil is set on coil, parallel resistance is attempted by the secondary coil of arc suppression coil, parallel resistance is controlled by switch Switching;For neutral by arc extinction coil grounding system, change the inductance value of arc suppression coil;Only need to be short when being grounded location determination Time changes the phase-to-ground voltage of region three
The power distribution network local ground fault detection system of the present invention is as follows:
The power distribution network local ground fault detection system include data syn-chronization detecting system, data acquisition communication system, Data background processing system;
The course of work of the power distribution network local ground fault detection system is as follows:
A, multiple regions delimited in power distribution network;
B, data syn-chronization detecting system can provide unified synchronizing signal to the current sensing means of distributing installation;Data Synchronous detecting system detects the size of each electric current using the current sensing means of distributing installation and each electric current by negative becomes positive zero passage Put the time difference relative to synchronizing signal, or each electric current of detection is relative to the phase difference of synchronizing signal;
C, data acquisition communication system can gather the current data of each current sensing means detection, and by the electric current of collection Data are sent to data background processing system;Data communication method can use the side such as wire communication, optical-fibre communications, wireless telecommunications Formula, wireless telecommunications can use GPRS communication modes;
D, data background processing system utilizes the current data from data acquisition communication system, is counted respectively for each region Region is calculated to earth-current
E, data background processing system is according to foregoing power distribution network local ground fault detection method or device methods described, Using the region in each region to earth-currentData, respectively for whether there is earth fault inside each region decision region, from And realize the region for determining to have earth fault in numerous regions.
Described power distribution network local ground fault detection system also includes voltage check device, is examined using voltage check device Survey the residual voltage or three phase-to-ground voltages in each region;
Described power distribution network local ground fault detection system can include one or more voltage check devices, voltage inspection The voltage of detection bus in transformer station, or detection circuit in some switching station outside transformer station can be arranged on by surveying device Voltage, or on certain section of circuit detect circuit voltage;
Data syn-chronization detecting system can also provide unified synchronizing signal to the voltage check device of distributing installation;Data Synchronous detecting system can utilize be arranged on power distribution network in voltage check device detection voltage size and voltage relative to The time difference of synchronizing signal or phase difference;Data acquisition communication system can gather the voltage number of each voltage check device detection According to, and the voltage data of collection is sent to data background processing system;
Data background processing system is according to the voltage data from data collecting system, it is determined that the voltage number in each region According to;
Data background processing system can be according to described in foregoing power distribution network local ground fault detection method or device Method, using the region in each region to earth-currentWith the phase-to-ground voltage of region threeData, or utilize each area The region in domain is to earth-currentWith region residual voltageData, respectively for whether there is ground connection inside each region decision region Failure, so as to realize the region for determining to have earth fault in numerous regions.
The power distribution network local ground fault detection system can also gather the state of related switch in power distribution network, will switch State data background processing system is sent to together with voltage, current data, by data background processing system according to switch State determines each region is currently in connected state with which voltage check device respectively, so as to determine that each region is currently adopted respectively The voltage data detected with which voltage check device.
Described power distribution network local ground fault detection system can be combined with electrical power distribution automatization system, utilize power distribution automation Terminal unit detection voltage data, current data and the on off state of system distributing installation, utilize the logical of electrical power distribution automatization system News device is sent to power distribution network local ground fault detection system by data are detected, and realizes the Earth design work(of power distribution network Energy;Distribution net work earthing fault alignment system can by be grounded positioning result be sent in electrical power distribution automatization system, for quickly every From creating conditions for earth fault region;The function of described power distribution network local ground fault detection system can also directly merge Into electrical power distribution automatization system, the repertoire of power distribution network local ground fault detection system is completed by electrical power distribution automatization system.
Beneficial effects of the present invention
1st, power distribution network is divided into multiple regions, determined by measured zone carrying out earth fault region based on earth-current Position, participate in calculating be the region region to earth-current, region voltage-to-ground, region parameter over the ground, which uses with system Kind neutral grounding mode is not related.So the present invention is applicable not only to system with non effectively earth ed neutral, and centering Point is similarly effective through small resistance grounding system.
2nd, for the power distribution network comprising DG, DG can be arranged to a single region, detect DG earth fault;DG's The local ground fault detect to other regions is accessed not have an impact.For micro-capacitance sensor, the method that the present invention can also be used Multiple regions are divided in the range of micro-capacitance sensor, realize the zone location problem of the earth fault in the range of micro-capacitance sensor.
3rd, it is equally applicable for multipoint earth faults, local ground fault detection method of the invention.Earth fault be present Region all can domain of the existence to the anomalous variation of earth-current, can be with due to carrying out earth fault judgement respectively to each region It was found that the region of earth fault all be present.
4th, using region three relatively parameter, the phase-to-ground voltage of region three and region judge earth-current local ground therefore Barrier, it is contemplated that the relatively factor such as imbalance of parameter of the imbalance of voltage, three, Earth Fault Detection precision is high, is connect to high resistant Earth fault good positioning effect.
5th, local ground failure is judged to component of the earth-current in residual voltage direction using region, due to not accounting for area The unbalanced influence of the relatively parameter of domain three, causes to decrease to the accuracy of detection of high resistance earthing fault, but can save Remove the detection device of the relatively parameter of region three, simplify system, cost of investment reduces, if coordinate arc suppression coil and in resistance The measure of current in resistance property is improved, the effect of Earth design can be improved.
6th, in increase system current sensing means packing density, increase the quantity in region, reduce the region in each region It distributed capacitance over the ground, can further remove voltage check device from, judge earth-current each region according only to the region in each region With the presence or absence of earth fault, system is further simplified, and obtain ideal ground connection locating effect.
7th, due to carrying out earth fault zone location using power frequency data, be advantageous to and existing relay protection system knot Close;If power distribution network is equipped with power distribution automation equipment, the collection of electric current, voltage data is completed using power distribution automation equipment And upload, the zone location of earth fault is carried out in distribution main station system, recycles power distribution automation equipment to be grounded event Hinder the automatism isolation in region.
Brief description of the drawings
The basic principle schematic of Fig. 1 local ground failure detectors
The basic principle schematic of Fig. 2 local ground failure detectors
The basic principle schematic of local ground fault detection systems of the Fig. 3 by the use of GPS second pulse as synchronizing signal
Fig. 4 is directed to the power distribution network local ground fault detect principle schematic for dividing switchgear house to be provided with voltage-to-ground detection means
Fig. 5 has the basic principle schematic of the local ground failure detector of region zero sequence voltage detection device
The principle schematic of the data acquisition communication system of Fig. 6 ground-fault detection systems
The emulation experiment schematic diagram of Fig. 7 local ground fault detection methods
It is a simplified neutral by arc extinction coil grounding system as shown in Figure 1, figure includes the two of power transformer Secondary coil, arc suppression coil XH, three road outlet switch QF1, QF2, QF3, corresponding three switches are provided with three zero sequence current mutual inductances Device CT1, CT2, CT3, each zero sequence current mutual inductor detect the region in a region to earth-current respectively.In each area, Region susceptance over the ground is represented using capacitor, region 1 three relatively susceptance be BEA1、BEB1、BEC1, the three of region 2 are relatively electric Receive as BEA2、BEB2、BEC2, region 3 three relatively susceptance be BEA3、BEB3、BEC3
CT1, CT2, CT3 difference detection zone 1, region 2, the region in region 3 are to earth-current
An earth fault is provided with region 1, A phases are grounded, and ground connection transition resistance is GEA1;Region 2 and region 3 do not have Earth fault.
Power transformer secondary coil is Y-connection mode, and arc suppression coil XH, extinguishing arc are connected between neutral point and the earth Coil sets resistors in parallel RP, by switching J control resistors RPInput and excision.Three phase-to-ground voltages of system are respectively:
The relation of each electric current in region 1 is as follows:
Three relatively capacity currents:
Region is to earth-current capacitive component:
A relatively current in resistance property (electric currents for flowing through earth fault):
Region is to earth-current resistive component:
Region is to earth-current:
The relation of each electric current in region 2 is as follows:
Three relatively capacity currents:
Region is to earth-current capacitive component:
Region is to earth-current resistive component:
Region is to earth-current:
The relation of each electric current in region 3 is as follows:
Three relatively capacity currents:
Region is to earth-current capacitive component:
Region is to earth-current resistive component:
Region is to earth-current:
Earth-fault current and arc suppression coil compensation electric current, the relation of capacitance current when switching J disjunctions:
Arc suppression coil compensation electric current is
Earth-fault current and arc suppression coil compensation electric current, the relation of capacitance current:
Earth-fault current and arc suppression coil compensation electric current, the relation of capacitance current when switching J closures:
Arc suppression coil compensation electric current is
The electric current of arc suppression coil parallel resistance:
Earth-fault current and arc suppression coil compensation electric current, the relation of capacitance current:
The input of arc suppression coil parallel resistance can cause three phase-to-ground voltagesChange, three is relative Ground voltageChange size it is relevant with many factors, influence factor is relatively distributed electricity including system three Hold, be grounded transition resistance, arc suppression coil inductance value, arc suppression coil parallel resistance etc..Before being put into due to arc suppression coil parallel resistance A phase-to-ground voltages afterwardsOccur change, so arc suppression coil parallel resistance input before and after region 1 current in resistance propertyAlso will Change;If ground connection transition resistance is REA1Smaller, the input of arc suppression coil parallel resistance will make current in resistance propertyOccur Very big change.
Local ground fault detection method:(illustrating local ground fault detection method with reference to Fig. 1)
1st, local ground fault detection method is summarized:
A region delimited in power distribution network, an equipment or one section of circuit can be only included in the region, also with bag Include connected and some adjacent equipment and some sections of circuits;
The region in the region is detected to earth-current using current sensing meansDetection zone is to earth-currentMethod It is:1. detection flows into whole electric currents in the region, these electric currents are added according to the direction vector inside inflow region and obtained Region is to earth-current2. whole electric currents that the earth is flowed into from the region are detected, by these electric currents according to the direction for flowing into the earth Vector addition obtains region to earth-current
Parameter includes the relatively conductance G of region three over the ground in the region in the regionEA、GEB、GECWith the relatively susceptance of region three BEA、BEB、BEC
Apply three phase-to-ground voltages for the regionBy generating region to earth-currentRegion three Phase-to-ground voltageRegion is to earth-currentWith the relatively susceptance B of region threeEA、BEB、BEC, region three it is relative Ground conductance GEA、GEB、GECBetween following relation be present:
Wherein, the phase-to-ground voltage of region threeWith the relatively conductance G of region threeEA、GEB、GECProduce area Domain is to earth-current resistive componentThe value is three phase region to earth-current resistive componentVector:
The phase-to-ground voltage of region threeWith the relatively susceptance B of region threeEA、BEB、BECGenerating region is over the ground Electric current capacitive componentThe value is three phase region to earth-current capacitive componentVector:
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector With,
Wherein region is to earth-current resistive componentDirectly related with earth fault, the failure of earth fault is flowed through in reflection The size of electric current;
During power distribution network has earth fault, if earth fault is not present in the region, region is hindered earth-current Property componentVery little,Region is to earth-currentEqual to region to earth-current capacitive componentI.e.If the area When domain has earth fault, region is to earth-current resistive componentAbnormal increase is will appear from, also results in region to earth-current Abnormal increase is will appear from, region is to earth-currentWith region to earth-current resistive componentRelative to residual voltagePhase difference Also will change;The region obtained using detection is to earth-currentZoning is to earth-current resistive componentAccording to region To earth-current resistive componentSize and/or walking direction described in region whether there is earth fault;
During power distribution network has earth fault, the artificial phase-to-ground voltage of adjustment region three can be passed through The resistive component of the region to earth-current in earth fault region be present in increaseWiden that earth fault region to be present normal with other Resistive component of the region to earth-current between regionThe gap of size, improve according to region to earth-current resistive componentIt is big Region described in small and/or walking direction whether there is the effect of earth fault method;
During power distribution network has earth fault, three phase-to-ground voltages of power distribution network can also be artificially adjustedThe region for making to have earth fault region is to earth-currentWith region to earth-current resistive componentOccur Change, according to region to earth-currentAnd/or region is to earth-current resistive componentSituation of change, whether judge the region Earth fault be present.
2nd, local ground fault detection method 1:
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region three in the region relatively susceptance BEA、BEB、BEC
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith the phase-to-ground voltage of region threeUsing region to earth-current capacitive componentThe phase-to-ground voltage of region threeAnd region Three relatively susceptance BEA、BEB、BECBetween relation:
The region in the region is calculated to earth-current capacitive componentAccording to region to earth-currentRegion holds to earth-current Property componentWith region to earth-current resistive componentBetween relation:
Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge described in Region whether there is earth fault;
If the phase-to-ground voltage of region threeChange, region is to earth-current resistive componentWill hair Changing;Can be taking human as the phase-to-ground voltage of adjustment region threeThe region in earth fault region be present in increase To the resistive component of earth-currentWiden and region be present between earth fault region and other normal regions to the resistive of earth-current ComponentThe gap of size, improve the effect that detection has earth fault region;
Three phase-to-ground voltages of artificial adjustment power distribution networkThe region for artificially changing each region is electric over the ground Fluid resistance componentSize, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed; So can also be according to the region in the region to earth-current resistive componentThe size of change judges that the region whether there is Earth fault.
Because this method utilizes the phase-to-ground voltage of region threeWith the relatively susceptance B of region threeEA、BEB、 BECThe region in the region is calculated to earth-current capacitive componentAccurate region can be obtained to earth-current capacitive component Value, so the region being calculated is to earth-current resistive componentAlso relatively more accurate, this method also has for high resistance earthing fault Good effect.The relatively susceptance B of region threeEA、BEB、BECCan be with on-line checking.
3rd, local ground fault detection method 2:
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region in the region total susceptance B over the groundE (BE=BEA+BEB+BEC);
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltage
Utilize region residual voltageWith region total susceptance B over the groundECapacitive component of the zoning to earth-current
According to region to earth-currentCapacitive component of the region to earth-currentAnd region is between earth-current resistive component Relation:
Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge described in Region whether there is earth fault;
If region residual voltageChange, region is to earth-current resistive componentIt will change;Can be taking human as Adjustment region residual voltageThe resistive component of the region to earth-current in earth fault region be present in increaseWiden to exist and connect Resistive component of the region to earth-current between earth fault region and other normal regionsThe gap of size, improve to detect to exist connecing The effect in earth fault region;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed;So can also according to institute The region in region is stated to earth-current resistive componentThe size of change judges that the region whether there is earth fault.Region is over the ground Total susceptance BECan be with on-line checking.
4th, local ground fault detection method 3:
For the region, when earth fault occurs in power distribution network, artificial three phase-to-ground voltages for adjusting power distribution networkThe region residual voltage detected before record adjustment voltageWith region to earth-currentRecord adjustment electricity The region residual voltage detected after pressureWith region to earth-current
It is to earth-current by the region after adjustment voltageConvert for adjustment voltage before region residual voltageIt is right The reduced value answered
The region after adjustment voltage is calculated to earth-current reduced valueWith the region before adjustment voltage to earth-current's Difference
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector With:
If earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, region is to earth-current Equal to region to earth-current capacitive componentI.e.:
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, capacitive point of the region to earth-current AmountWith region residual voltageBetween linear relationship be present:
If the region is not present earth fault, and the region three in the region relatively susceptance BEA、BEB、BECIt is Symmetrically, the region after the adjustment voltage in the region is to earth-current reduced valueWith the region before adjustment voltage to earth-currentShould be equal, i.e.,:
If the region has earth fault, region is to earth-current resistive componentAddition makeWithNo It is equal again,Also just it is no longer equal to 0;Size can be with reflecting regional to earth-current resistive componentSize, can With according to region current differential over the groundSize judge that the region whether there is earth fault.
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive component Size not only with region residual voltageSize it is relevant, also with region residual voltageDirection it is relevant, region is electric over the ground The capacitive component of streamWith region residual voltageBetween not necessarily or linear relationship, i.e.,:
According to region current differential over the groundSize judge that the region just increases with the presence or absence of the method for earth fault Uncertain factor is added;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, capacitive point of the region to earth-current AmountWith region residual voltageBetween basic or linear relationship;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, region pair The capacitive component of earth-currentSize to region to earth-currentSize influence it is little;
If meeting the two conditions, capacitive component that can be according to region to earth-currentWith region residual voltageIt Between linear relationship be present to handle, still can be according to region current differential over the groundSize whether judge the region Earth fault be present.
This method cable run effect is preferable, because the relatively susceptance B of cable run region threeEA、BEB、BECThe degree of balance Preferably.
5th, local ground fault detection method 4:
For the region, if earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, Region is to earth-currentEqual to region to earth-current capacitive componentI.e.:
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-currentAdvanced region Residual voltage
If earth fault occurs in the region, the region region is to earth-current resistive componentRegion is electric over the ground StreamIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector:
Because region is to earth-current resistive componentAddition, make region to earth-currentWith region residual voltageBetween Phase difference change, region is to earth-currentAdvanced region residual voltageRelation no longer set up;
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltage's Phase difference θ, it can judge that the region whether there is earth fault according to the value of phase difference θ;
Can be taking human as the adjustment phase-to-ground voltage of power distribution network three, the region that change has earth fault region is resistive to earth-current ComponentMake region to earth-currentWith region residual voltagePhase difference θ farther away from " region is to earth-currentAdvanced area Domain residual voltage" relation, so as to more accurately judge to have the region of earth fault.
The region can also be directed to, when earth fault occurs in power distribution network, the three of artificial adjustment power distribution network are relatively electric PressureRegion before record adjustment voltage is to earth-currentWith region residual voltagePhase difference θ1With The region of the detection after voltage is adjusted to earth-currentWith region residual voltagePhase difference θ2, calculate the change of phase difference Δ θ=θ21If the region of affiliated area is to earth-currentWith region residual voltagePhase difference variation delta θ compared with Greatly, it can determine whether that the region has earth fault;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, " region is to earth-currentAdvanced region Residual voltage" relation with regard to invalid, still, if the region three in the region relatively susceptance BEA、BEB、BECIt is not right Title degree is not serious, can be approximately considered that " region is to earth-currentAdvanced region residual voltage" relation still set up , still can be according to region to earth-currentWith region residual voltageThe size of phase difference θ or the change of phase difference sentence The disconnected region whether there is earth fault.
In the region divided in power distribution network, the region three in some regions relatively susceptance B might haveEA、BEB、BECVery It is small, for example, a ring main unit as a region, it is necessary to multiple zero sequence current mutual inductors detect a ring main unit region over the ground Electric currentIt is limited to the precision of detection, the region being likely to be obtained is to earth-currentPhase error it is larger, be unfavorable for correctly basis Region is to earth-currentWith region residual voltagePhase difference θ judge that the region whether there is earth fault;Because in the presence of The region respective regions of earth fault are to earth-currentAlso it is larger, can be in region to earth-currentLarger subregion scope Inside do earth fault judgement.
6th, local ground fault detection method 5:
During defined area, reduce regional extent in equipment quantity and/or reduce regional extent in circuit length, reduce The relatively susceptance B of region threeEA、BEB、BEC, by the region in regional extent to earth-current capacitive componentControl the model in very little In enclosing;
When earth fault occurs in power distribution network, the region in the region is detected to earth-current
When earth fault is not present in the region, no Regional Economy three-phase voltage-to-groundHow to become Change, region is to earth-current capacitive componentOr very little, and in the absence of earth fault region region to resistive point of earth-current AmountBe approximately equal to 0, thus in the absence of earth fault region region to earth-currentVery little;
When there is earth fault in the region, the region in the region is to earth-current resistive componentIncrease, the area The region in domain is to earth-currentIt will increase therewith, region is to earth-currentSize can be with reflecting regional to earth-current resistive componentSize;Can be according to region to earth-currentSize judge that the region whether there is earth fault;
The region pair that earth fault region be present can be increased by artificially adjusting the method for the phase-to-ground voltage of power distribution network three Earth-current resistive componentRegion be present between earth fault region and other normal regions to earth-current resistive component in increasing Gap, so as to more accurately judge to have the region of earth fault;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed, and earth fault region be present Region to earth-currentAlso will have greatly changed;So can also be according to the region in the region to earth-currentChange Size judge that the region whether there is earth fault.
Meeting the region three in each region relatively susceptance BEA、BEB、BECUnder the conditions of less, this method for including Various earth faults including high resistance earthing fault have good effect.Using the number that this method increase current detecting equipment Amount, but voltage detection device need not be installed, in this embodiment it is not even necessary to backstage, and can further reduce trouble shoot scope.
7th, local ground fault detection method 6:
The region in the region is detected to earth-currentWith region residual voltageBy region to earth-currentIt is decomposed into flat Row is in region residual voltageParallel componentWith perpendicular to region residual voltageVertical component
Region is to earth-current resistive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith it is parallel In region residual voltageParallel component
Region is to earth-current capacitive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith it is parallel In region residual voltageParallel component
Region is to earth-currentIt is region to earth-current resistive componentTwo components and region to earth-current capacitive componentTwo components sum;
If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-current capacitive component The residual voltage in the advanced regionThis time domain current parallel component over the groundWith Region is to earth-current capacitive componentIt is unrelated, only with region to earth-current resistive componentIt is relevant, and region current parallel over the ground ComponentWith region to earth-current resistive componentProportional relation be present, i.e.,:(if region is over the ground Electric current resistive componentWith the residual voltage in regionBetween angle be θ, K=1/cos θ);So can be by the region Region current parallel component over the groundAs region to earth-current resistive componentFor judging the region with the presence or absence of ground connection Failure;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive componentWith Region residual voltageNo longer must be vertical relation, parallel component of the region to earth-current capacitive componentIt is no longer equal to 0,Because region is to the parallel component of earth-current capacitive componentAddition, according to region current parallel over the ground ComponentJudge that the method for local ground failure increases uncertain factor;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, and region is to earth-current capacitive component Parallel component in residual voltage directionVery little;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, so area Domain is to parallel component of the earth-current capacitive component in residual voltage directionAlso very little;
If meeting the two conditions, region current parallel component over the ground can be approximately consideredWith region to earth-current Resistive componentProportional relation be present, i.e.,:So still can be by the region in region current parallel over the ground ComponentAs region to earth-current resistive componentFor judging that the region whether there is earth fault;
The region pair that earth fault region be present can be increased by artificially adjusting the method for the phase-to-ground voltage of power distribution network three Earth-current resistive componentRegion current parallel component over the ground be present between earth fault region and other normal regions in increasing Gap, so as to more accurately judge to have the region of earth fault;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentIt is big It is small, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed, and earth fault region be present Region current parallel component over the groundAlso will have greatly changed;So can also be according to the region in the region over the ground Current parallel componentThe size of change judges that the region whether there is earth fault.
This method is also preferable to cable run effect, because the region three of threephase cable relatively susceptance BEA、BEB、BEC The degree of balance it is preferable.
Fig. 2 is the basic principle schematic of local ground failure detector.
As shown in Fig. 2 having delimited a region to be detected in figure, parameter includes the relatively conductance of region three over the ground in region GEA、GEB、GECWith the relatively susceptance B of region threeEA、BEB、BEC
Power distribution network local ground failure detector include current sensing means, voltage check device, synchronous signal device, Data acquisition device, data processing equipment;
1st, detection of the region to earth-current:
Detection zone is to earth-currentNeed to utilize the electric current inside current transformer detection inflow region;In fig. 2, enclose 3 zero sequence current mutual inductors CT1, CT2, CT3 are equipped with around region to be detected, detect three and other area limit points respectively Zero-sequence current
The region in the region is to earth-current resistive componentFor:
The region in the region is to earth-current capacitive componentFor:
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector With,
Current sensing means is connected with current transformer, and current sensing means can detect the size of electric current;Current detecting Device is also connected with synchronous signal device, and current sensing means receives the synchronizing signal from synchronous signal device, detects electric current By bearing time difference of the positive zero crossing relative to synchronizing signal, or detection electric current relative to the phase difference of synchronizing signal.
Data acquisition device gathers the current data of each current sensing means detection, and send the data of collection to data processing Device.
Data processing equipment receives the current data from data acquisition device, by each electric current by the side flowed to inside region To vector addition, the region in the region is obtained to earth-currentPhase to earth-current relative to synchronizing signal of size and region Potential difference.
Electric currentDirection be to flow to inside region, region is to earth-currentValue be electric current's Vector.
2nd, the detection of three phase-to-ground voltages and residual voltage:
In fig. 2, threephase potential transformer PT and voltage check device are also provided with, two groups of voltage transformer setting is secondary Coil, one group is used to detect three phase-to-ground voltagesOne group is connected as open-delta and is used to detect zero sequence VoltageTwo groups of secondary coils are connected with voltage check device.
Voltage check device can detect the size of detection voltage, and voltage check device is also connected with synchronous signal device, Voltage check device receives the synchronizing signal from synchronous signal device, and detection voltage is by bearing positive zero crossing relative to synchronous letter Number time difference, or detection voltage relative to synchronizing signal phase difference.Shown voltage check device can detect in fig. 2 Three phase-to-ground voltagesSize and three phase-to-ground voltagesRelative to synchronizing signal Time difference or phase difference, residual voltage can also be detectedSize and residual voltageRelative to the time difference of synchronizing signal Or phase difference;
Data acquisition device can the detection of collection voltages detection means voltage data, and send the voltage data of collection to data Processing unit;
Data processing equipment receives the voltage data from data acquisition device, obtains the phase-to-ground voltage of region three, zero sequence The size of voltage and three phase-to-ground voltages, residual voltage relative to synchronizing signal phase difference.
Data processing equipment can also be by the phase-to-ground voltage of region threeVector addition, obtain region zero Sequence voltageSize and region residual voltageIt is as follows relative to the phase difference of synchronizing signal, calculation formula:
In detail in this figure, voltage transformer is connected to the outside in region to be detected, the voltage data that will be detected in region exterior Directly as the voltage data inside region.Voltage check device can also be connected to the inside in region to be detected, directly detect The voltage data in region to be detected.
Data processing equipment is using region to earth-currentWith region residual voltageOr the region pair obtained using detection Earth-currentWith the phase-to-ground voltage of region threeAccording to foregoing local ground fault detection method, institute is judged State region and whether there is earth fault.
Fig. 3 is the basic principle schematic of the local ground fault detection system by the use of GPS second pulse as synchronizing signal.
As shown in figure 3, be transformer station's minimum system, include inside transformer station transformer T1, voltage transformer pt 1, Bus, 5 return back out line.The 5 of transformer station return back out line and all install zero sequence current mutual inductor.Wherein the 4th, which returns back out line, is connected to an opening and closing Institute, opening and closing all two return back out line, and zero sequence current mutual inductor is all installed in the inlet wire of switching station and outlet.
Whole power distribution network is divided into 9 regions by 8 zero sequence current mutual inductors.Substation bus bar part is region 1, including Transformer secondary, voltage transformer 1 time and bus, the region in region 1 are detected to earth-current by CT1~CT5, CT1~CT5 detections Electric current by flow into bus direction vector be added to obtain the region in region 1 to earth-current1st return back out line, the 2nd return back out line, 3rd returns back out line, the 5th to return back out line be respectively region 2, region 3, region 4, region 6, detects this by CT1, CT2, CT3, CT5 respectively The region in a little regions is to earth-current4th return back out line to the circuit between switching station be region 5, region 5 Region to earth-currentIt is added to obtain by the direction vector for flowing to cable with the electric current that CT6 is detected by CT4;Switching station's bus wire portion It is divided into region 7, the region in region 7 is to earth-currentBy the electric current of CT6~CT8 detections by the direction vector for flowing to switching station's bus Addition obtains;It is respectively region 8 and region 9 that the two of switching station, which return back out line, respectively by CT7 and CT8 detection zones 8 and region 9 Region is to earth-current
Each corresponding current sensing means of zero sequence current mutual inductor, current sensing means can detect the size of electric current; Current sensing means can receive the synchronizing signal from data acquisition device simultaneously, be connect in data acquisition device equipped with gps clock Receiving apparatus, different location can utilize GPS second pulse to obtain the high synchronizing signal of precision;Current sensing means can detect each electric current Become time difference of the positive zero crossing relative to synchronizing signal by negative.
The voltage check device being connected with voltage transformer can also receive the synchronizing signal from data acquisition device, voltage Detection means can detect the size of three phase-to-ground voltages, and also detectable three phase-to-ground voltages become positive zero crossing relative to same by negative Walk the time difference of signal.
Data acquisition device inside transformer station directly can be passed the data of the voltage and current collected by connection It is sent in local ground fault detection system.The current data of the data acquisition device collection of switching station passes through the side that is wirelessly transferred Formula is sent in local ground fault detection system, and being wirelessly transferred can use GPRS wireless communication modes etc. to realize.
Local ground fault detection system receives the voltage from data acquisition device, current signal, for each region The electric current related to the region is added by the direction vector flowed to inside region, the region that can obtain each region is electric over the ground Stream.If necessary to residual voltage, it can be added and obtained by three phase-to-ground voltages for detecting voltage check device;In this instance, What voltage check device detected is the voltage in substation bus bar region (region 1);For convenience, while in order to save cost, entirely The voltage data that 9 each region of portion is all obtained using being measured in region 1.
Each voltage, the detection data of electric current are needed to stamp time tag when uploading, and local ground fault detection system is adopted The calculating of correlation is carried out with the voltage of synchronization, current data, judges the region of earth fault be present.
Fig. 4 is the power distribution network local ground fault detect principle that voltage check device and distribution power are provided with for switching station Schematic diagram
Transformer station is provided with voltage transformer pt 1, and the secondary of PT1 connects main website voltage check device, detect substation bus bar three Phase-to-ground voltage;Transformer station has 3 to return back out line QF1~QF3;Wherein QF1 is connected to a switching station, and QF3 connects with grounding transformer Connect.QF4 is the service entrance switch of switching station, is opened and closed all 4 outlet switch QF5~QF8.Switching station is provided with voltage transformer pt 2, The secondary of PT2 connects substation voltage check device, detects the phase-to-ground voltage of bus three of switching station.
11 regions delimited altogether, by CT1~CT3 detection zones 1 (including the bus of transformer station, transformer T1 secondary line Circle, the primary winding of voltage transformer) region to earth-currentBy (the transformer station to distribution electricity of CT1 and CT4 detection zones 2 The cable of room) region to earth-currentBy the region of CT2 detection zones 3 to earth-currentBy CT3 detection zones 4 (including Grounding transformer and arc suppression coil) region to earth-currentBy CT4~CT8 detection zones 5 (inside switching station's power distribution cabinet) Region is to earth-currentBy the region in CT5 and CT6 difference detection zones 6 and region 7 to earth-currentBy CT7 and CT8 Detection zone 8 (outlet of switch QF7 controls and high-tension motor) and region 9 (outlet of switch QF8 controls and distributed power generation Machine) region to earth-currentBy the region of CT9 detection zones 10 (cable 1) to earth-currentBy CT10 and CT11 The region of detection zone 11 (cable 2) is to earth-current
The screen layer of cable is the equipment of cable, during cable normal operation, capacitance current be flowed into by screen layer it is big Ground.When making end, screen layer is drawn using shielding layer grounding line, is determined to use cable according to the concrete condition at scene Two-terminal-grounding, or one end ground connection.In Fig. 4, the head end of the external shielding layer of cable 1 was passed through by ground connection, tail end Voltage protector is grounded, and head end is grounded through precision current transformer CT9, and the region that this bar cable is detected by CT9 is electric over the ground StreamThe head and the tail both ends of the external shielding layer of cable 2 are all by ground connection, and the ground wire of head end is through precision current mutual inductance Device CT10, the ground wire of tail end is through precision current transformer CT11, by the electric current that CT10 and CT11 is measured by inflow the earth Direction vector is added, and can obtain the region of this bar cable to earth-current
Three phase-to-ground voltages that 1~region of region 4 is detected using main website voltage check device;5~region of region 11 uses Three phase-to-ground voltages of substation voltage check device detection.
When transformer station is distant with switching station, load current is again larger, considers the influence of line drop, can be opened and closed Set voltage check device, the accuracy of three phase-to-ground voltages of switching station's supply district inner region is improved, improve switching station and supply The effect of local ground fault detect in electric scope.
The transmission line circuit being connected with generator can also be used as a region, can detect the earth fault of generator.Generate electricity The access of machine judges not influence on the earth fault in other regions.
Fig. 5 is the basic principle schematic of ring network power supply land ground fault detection device.
As shown in figure 5, transformer station is sectionalized single busbar connection powering mode, line is returned back out by adhering to two sections of buses two separately and is connected into a ring Road, form ring network power supply circuit.
Whole circuits are divided into 17 regions, including 3 ring main unit regions, 13 lands and 1 transformer region, by 25 current transformers (including phase current mutual inductor and zero sequence current mutual inductor) measure the region in 17 regions to earth-current.Its In, region 2, region 5 and region 13 are ring main unit region, detect the earth fault inside ring main unit;Region 1, region 3, region 4th, region 6, region 7,9~region of region 12, each responsible one section of circuit in 14~region of region 17, a transformer is responsible in region 8; Wherein CT8~CT19 is split-phase current transformer.For occasions such as overhead transmission line, aerial buses, if being inconvenient to install zero sequence Current transformer, three-phase current is detected respectively using split-phase current transformer, zero-sequence current, zero sequence are calculated using three-phase current The accuracy of detection of electric current can reduce, but the same function of being grounded breakdown judge.
Two sections of buses have respective voltage check device respectively;By ring main unit switching station terminal unit (DTU), a feeder line distant place Terminal (FTU) and the detection means detection current data of transformer terminal unit (TTU) inside, if the voltage of distributing installation Detection means also completes the detection of voltage data in the lump, and the voltage of detection, current data are transmitted into background system, while will switch State also gathers and is sent to background system.
In the case of ring network power supply, same region may be powered by different power supplys, it is thus necessary to determine that in DATA REASONING Moment, each region was currently powered by which power supply, using the detection data of which voltage check device.Such as:I section buses Subregion in supply district because certain reason temporarily by II section bussed supplies, now these regions need female using II sections The voltage data of line carries out the judgement of local ground failure.Some loop grids may also relate to different substation, some regions It may relate to the possibility of multiple power supply power supplies, it is also desirable to handle using same method.
The data of which currently employed voltage check device of a region are determined, it is necessary to judge the current region and which electricity Pressure detection means is in connection status.Background system utilizes the state switched in current power distribution network, the current each region difference of analysis Which voltage check device connected state is in, determines that the voltage number of which voltage check device detection is respectively adopted in each region According to.
GPS module built in DTU, FTU, TTU needs of distributing installation, voltage, the current sensing means of distributing installation need The synchronous size and number of phases for detecting, obtaining voltage and current of voltage and current is realized using GPS standard time and pulse per second (PPS) According to.
The location information of earth fault can be supplied to electrical power distribution automatization system by local ground fault detection system, by with Electric automation system completes the isolation in earth fault region.It is of course also possible to the function bag by local ground fault detection system It is contained in electrical power distribution automatization system.
Fig. 6 is the principle schematic of the data acquisition communication system of local ground fault detection system.
Data acquisition communication system includes current sensing means, voltage check device, the data acquisition device of distributing installation And backstage.Data acquisition device is responsible for collection voltages detection means and the detection data of current sensing means, data acquisition device In contain GPS module, GPS module can receive standard time and pulse per second (PPS), and data acquisition device is sent out to voltage, current sensing means Send sense command, and send synchronizing signal, ensure all voltages, current sensing means can synchronization detect voltage, The size of electric current and the time difference relative to synchronizing signal or phase difference, and the result packing of detection is sent to backstage.
Communication between data acquisition device and backstage can use a variety of communication sides such as wired, wireless, optical fiber, GPRS Formula, two kinds of communication modes are employed in Fig. 6, are wire communication mode and GPRS wireless communication modes respectively.
The backstage of the system can also by communicate interconnection with other systems carry out data exchange, such as with power distribution automation system System realizes communication, and the status information of switch is obtained by electrical power distribution automatization system;Earth design information transmission can also be given Electrical power distribution automatization system, it is grounded the automatism isolation of fault zone.
Fig. 7 is the l-G simulation test schematic diagram of local ground fault detection method
The earth fault line selection and positioning difficulty of neutral by arc extinction coil grounding system are relatively large, so emulation experiment According to neutral by arc extinction coil grounding system configuration, the present disclosure applies equally to the small current neutral grounding system of other forms certainly System;When there is high resistance earthing fault for small resistance grounding system, the present invention is equally applicable.
Circuit is 10kV neutral by arc extinction coil grounding systems, within the system, by 4 zero sequence current mutual inductor CT1 ~CT4 detects the zero-sequence current in 4 regions respectively, wherein region 4 be in order to embody neutral by arc extinction coil grounding system compared with Big capacitance current and set, emulation experiment is carried out just for region 1, region 2, region 3.It is provided with emulation experiment circuit The resistance R1 being connected in parallel on arc suppression coil, R1's and connect and cut off by switching J1 control resistance, be also provided with being connected to phase line with Offset resistance R2, R3, R4 between the earth, by the access and excision that switch J2, J3, J4 control offset resistance.
L-G simulation test 1:Using the phase-to-ground voltage of region three and region three relatively susceptance zoning to earth-current capacitive The method of component searches earth fault
Parameter such as table 1, arc suppression coil reactance are 0.2H over the ground in region in emulation experiment;A phases in region 2 set one Earth fault, fault resstance 5k Ω.
Table 1
Table 2 is three phase-to-ground voltages and region current measurement data over the ground.
Table 2
In table 2Be respectively region 1, region 2, region 3, region 4 region to earth-current,It is The compensation electric current of arc suppression coil.
Using the capacitance in each region as given value, the capacitive component of the region to earth-current in each region is calculatedUtilize
Each region is calculated to earth-current resistive componentResult of calculation such as table 3.
Table 3
From table 3 it can be seen that current in resistance property is maximum over the ground in the region in region 2, there is earth fault in region 2.If setting Region is to earth-current resistive componentSetting value be 500mA, it is possible to find out the region that earth fault be present.
This method is using calculating of the three relatively parameter progress regions to earth-current capacitive component, so than relatively accurately Value of the region to earth-current resistive component is calculated, there is good effect for high resistance earthing fault.Set in this example Grounding resistance is 5k Ω, can clearly distinguish the region where earth fault.
L-G simulation test 2:Using region residual voltage and region over the ground total susceptance zoning to earth-current capacitive component Method searches earth fault
Parameter such as table 4, arc suppression coil reactance are 0.2H over the ground in region in emulation experiment;A phases in region 2 set one Earth fault, fault resstance 1k Ω.
Table 4
Table 5 is three phase-to-ground voltages and region current measurement data over the ground.
Table 5
In table 5Be respectively region 1, region 2, region 3, region 3 region to earth-current,It is The compensation electric current of arc suppression coil.
Using the capacitance in each region as given value, the capacitive component of the region to earth-current in each region is calculatedUtilize
Each region is calculated to earth-current resistive componentResult of calculation such as table 6.
Table 6
As can be seen from Table 6, current in resistance property is maximum over the ground in the region in region 2, and region 2 has earth fault.If setting Region is to earth-current resistive componentSetting value be 500mA, it is possible to find out the region that earth fault be present.
The experiment is compared with l-G simulation test 1, and due to region 3 three, relatively distribution capacity is bigger, and imbalance be present, And use region residual voltage and region over the ground total susceptance zoning to earth-current capacitive componentWhen have ignored three relatively The unbalanced problem of susceptance, cause the region in region 3 to earth-current resistive componentCalculation error is slightly larger, and effect is not as emulation Experiment 1.
L-G simulation test 3:Using region to parallel component of the earth-current in residual voltage directionSearch earth fault
Parameter such as table 7, arc suppression coil reactance are 0.2H over the ground in region in emulation experiment;A phases in region 2 set ground connection event Hinder the Ω of resistance 500.
Table 7
Test respectively do not adjust between voltage, arc suppression coil parallel resistance, B phases and the earth connect biasing resistor, adjustment disappear Four kinds of situations such as arc coil inductance value, the emulation data under four kinds of phase-to-ground voltages of region three are put together and are compared.
Table 8 is the emulation data under four kinds of voltages.
Table 8
In table 5Be respectively region 1, region 2, region 3, region 3 region to earth-current,It is The compensation electric current of arc suppression coil.
Table 9 be under four kinds of voltages region to earth-currentCapacitive component of the region to earth-currentEarth-current is hindered with region Property componentData compare:
From the effect of the data analysis several method in table:
1st, from region to earth-currentData row it can be seen that, it is impossible to according only to each region region to earth-currentIt is big Earth fault be present in small which region of judgement;Although earth fault is not present in region 3, because the region in region 3 is electric over the ground Receive larger, the region is to earth-currentAlso it is larger;
2nd, from region to earth-currentData row are as can be seen that according to region to earth-current resistive componentChange can be with Be present the region of earth fault in accurate judgement, do not influenceed by voltage change, also not influenceed by susceptance is unbalanced;
3rd, from region to earth-currentData row using the method for adjustment voltage as can be seen that can be increased in the presence of ground connection The region of fault zone is to earth-current resistive componentBe advantageous to the judgement in earth fault region be present;
4th, from region to earth-currentData row can be seen that after there is earth fault, using arc suppression coil and connecting resistance Or the method that resistance is connected between phase line and the earth, the region that can make to have earth fault region is to earth-currentPhase angle with The region of other normal regions is to earth-currentPhase angle there is larger difference, can utilize this feature detection ground connection be present therefore The region of barrier.But the method DeGrain of adjustment arc suppression coil inductance value.
Table 10 is to parallel component of the earth-current in residual voltage direction according to regionJudge the number of earth fault be present According to:
Table 10
From the data analysis in table, can draw to draw a conclusion:
1st, after singlephase earth fault occurs in neutral by arc extinction coil grounding system, directly according to region current parallel over the ground ComponentThe region for judging to have earth fault has difficulties;Arc suppression coil inductance value is adjusted, effect is also bad;
2nd, arc suppression coil parallel resistance or input bias resistance, which can increase, has earth fault region and normal region Region current parallel component over the groundBetween gap, so recommend using input resistance method.
L-G simulation test 4:Local ground trouble shoot method using reduction region to earth-current capacitive component
Parameter such as table 12, arc suppression coil reactance are 0.2H over the ground in region in emulation experiment;" region 2 " set one connect Earth fault, fault resstance 1k Ω.
Table 12
Table 13 is three phase-to-ground voltages and region current measurement data over the ground.
Table 13
Region 4 represents other regions, is not taken into account.As can be seen from Table 13, in region 1, region 2 and region 3, The region in region 2 is to earth-currentChange is maximum, and region 2 has earth fault.If the region three in each region is relatively electric Receive BEA、BEB、BECSmaller, the effect of this method is also better;The method of adjustment voltage can be coordinated to increase if necessary and ground connection be present The region of fault zone is to earth-currentMake the region that earth fault be present more obvious;This method only needs detection zone electric over the ground StreamCan is grounded fault location, it is not necessary to detects voltage, it is not necessary to detects distribution capacity, in this embodiment it is not even necessary to backstage, Individually detected directly against a region, such as a ring main unit can be directed to and carry out Earth Fault Detection, so should Method is also to have promotional value.
In terms of the result of above-mentioned 5 emulation experiments, l-G simulation test 1 is (relative using the phase-to-ground voltage of region three and region three Method of the ground susceptance zoning to earth-current capacitive component) accuracy in detection highest, l-G simulation test 5 is (using reduction region pair The local ground trouble shoot method of earth-current capacitive component) cost of investment is minimum.
For cable and overhead transmission line joint line, the larger power distribution network of supply district, the distributed capacitance phase in each region Difference is larger, and also exist three relatively distribution capacity it is uneven, it is proposed that it is relative using the phase-to-ground voltage of region three and region three Method of the ground susceptance zoning to earth-current resistive component.
It is small for supply district, the little power distribution network of line distribution capacitance, it is proposed that using reduction region to earth-current capacitive The method that the local ground trouble shoot method of component searches earth fault, the relevant device of detection line parameter circuit value can be saved, is not required to Voltage is detected, if increase current detecting equipment, and can also further reduce the scope of trouble point lookup.
Modification is made to the present invention, which kind of method no matter to realize the synchronous detection of voltage, current phase angle using;No matter adopt Which kind of method to obtain the parameter of region distribution capacity over the ground with;Which kind of method no matter used or utilizes which kind of instrument, instrument, backstage System realizes detection or calculating of the region to earth-current;Which kind of method no matter used or utilizes which kind of instrument, instrument, background system Realize detection or calculating of the region to earth-current resistive component;Which kind of method no matter used or utilizes which kind of instrument, instrument, backstage System realizes the local ground failure detector of the present invention, the function of local ground fault detection system;As long as using this hair Bright basic ideas realize power distribution network local ground fault detection capability or realize the zone location function of distribution net work earthing fault, Belong to protection scope of the present invention.

Claims (18)

1. a kind of power distribution network local ground fault detection method, it is characterized in that:
A region delimited in power distribution network, an equipment or one section of circuit can be only included in the region, also with including phase Company and some adjacent equipment and some sections of circuits;
The region in the region is detected to earth-current using current sensing meansDetection zone is to earth-currentMethod be:① Detection flows into whole electric currents in the region, and these electric currents are added according to the direction vector inside inflow region and obtain region pair Earth-current2. whole electric currents that the earth is flowed into from the region are detected, by these electric currents according to the direction vector phase for flowing into the earth Add and obtain region to earth-current
Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector, i.e.,:Wherein region is to earth-current resistive componentIt is three phase region to earth-current resistive component's Vector, i.e.,:
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Region is to earth-current capacitive componentIt is three phase region to earth-current capacitive componentVector, i.e.,:
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Region is to earth-current resistive componentDirectly related with earth fault, region is to earth-current resistive componentIt can reflect and flow through The size of the fault current of earth fault;
During power distribution network has earth fault, if earth fault is not present in the region, region is to resistive point of earth-current AmountVery little,Region is to earth-currentEqual to region to earth-current capacitive componentI.e.If the region is deposited In earth fault, region is to earth-current resistive componentAbnormal increase is will appear from, also results in region to earth-currentAlso will go out Now abnormal increase, region is to earth-currentWith region to earth-current resistive componentRelative to residual voltagePhase difference also will Change;The region obtained using detection is to earth-currentZoning is to earth-current resistive componentAccording to region over the ground Electric current resistive componentSize and/or walking direction described in region whether there is earth fault;
During power distribution network has earth fault, the artificial phase-to-ground voltage of adjustment region three can be passed throughIncrease Big resistive component of the region to earth-current that earth fault region be presentWiden and earth fault region and other normal areas be present Resistive component of the region to earth-current between domainThe gap of size, improve according to region to earth-current resistive componentSize And/or region described in walking direction whether there is the effect of earth fault method;
During power distribution network has earth fault, three phase-to-ground voltages of power distribution network can also be artificially adjusted The region for making to have earth fault region is to earth-currentWith region to earth-current resistive componentChange, according to region pair Earth-currentAnd/or region is to earth-current resistive componentSituation of change, judge that the region whether there is earth fault.
2. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region three in the region relatively susceptance BEA、 BEB、BEC
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith the phase-to-ground voltage of region threeUsing region to earth-current capacitive componentThe phase-to-ground voltage of region threeAnd region Three relatively susceptance BEA、BEB、BECBetween relation:
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The region in the region is calculated to earth-current capacitive componentAccording to region to earth-currentRegion is to earth-current capacitive point AmountWith region to earth-current resistive componentBetween relation:
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Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge the region With the presence or absence of earth fault;
If the phase-to-ground voltage of region threeChange, region is to earth-current resistive componentIt will become Change;Can be taking human as the phase-to-ground voltage of adjustment region threeThe region in earth fault region be present over the ground in increase The resistive component of electric currentWiden and region be present between earth fault region and other normal regions to the resistive component of earth-currentThe gap of size, improve the effect that detection has earth fault region;
Three phase-to-ground voltages of artificial adjustment power distribution networkThe region for artificially changing each region is hindered earth-current Property componentSize, the region in earth fault region be present to earth-current resistive componentIt will have greatly changed;So Can be according to the region in the region to earth-current resistive componentThe size of change judges the region with the presence or absence of ground connection event Barrier.
3. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
The methods of first passing through offline inspection or on-line checking or calculating, obtain the region in the region total susceptance B over the groundE(BE= BEA+BEB+BEC);
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltage
Utilize region residual voltageWith region total susceptance B over the groundECapacitive component of the zoning to earth-current
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According to region to earth-currentCapacitive component of the region to earth-currentAnd region is to the pass between earth-current resistive component System:
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Zoning is to earth-current resistive componentCan be according to region to earth-current resistive componentSize judge the region With the presence or absence of earth fault;
If region residual voltageChange, region is to earth-current resistive componentIt will change;Can be taking human as adjustment area Domain residual voltageThe resistive component of the region to earth-current in earth fault region be present in increaseWiden and earth fault area be present Resistive component of the region to earth-current between domain and other normal regionsThe gap of size, improve detection and earth fault area be present The effect in domain;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentSize, deposit In the region in earth fault region to earth-current resistive componentIt will have greatly changed;So can also be according to the region Region to earth-current resistive componentThe size of change judges that the region whether there is earth fault.
4. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
For the region, when earth fault occurs in power distribution network, artificial three phase-to-ground voltages for adjusting power distribution networkThe region residual voltage detected before record adjustment voltageWith region to earth-currentRecord adjustment electricity The region residual voltage detected after pressureWith region to earth-current
It is to earth-current by the region after adjustment voltageConvert for adjustment voltage before region residual voltageIt is corresponding Reduced value
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The region after adjustment voltage is calculated to earth-current reduced valueWith the region before adjustment voltage to earth-currentDifference
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Region is to earth-currentIt is region to earth-current resistive componentWith region to earth-current capacitive componentVector:
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If earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, region is to earth-currentIt is equal to Region is to earth-current capacitive componentI.e.:
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If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, capacitive component of the region to earth-currentWith Region residual voltageBetween linear relationship be present:
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If the region is not present earth fault, and the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical , the region after the adjustment voltage in the region is to earth-current reduced valueWith the region before adjustment voltage to earth-current Should be equal, i.e.,:
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If the region has earth fault, region is to earth-current resistive componentAddition makeWithNo longer phase Deng,Also just it is no longer equal to 0;Size can be with reflecting regional to earth-current resistive componentSize, Ke Yigen According to region current differential over the groundSize judge that the region whether there is earth fault.
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive componentSize Not only with region residual voltageSize it is relevant, also with region residual voltageDirection it is relevant, appearance of the region to earth-current Property componentWith region residual voltageBetween not necessarily or linear relationship, i.e.,:
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According to region current differential over the groundSize judge that the region increases with the presence or absence of the method for earth fault Uncertain factor;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, capacitive component of the region to earth-currentWith Region residual voltageBetween basic or linear relationship;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, region are electric over the ground The capacitive component of streamSize to region to earth-currentSize influence it is little;
If meeting the two conditions, capacitive component that can be according to region to earth-currentWith region residual voltageBetween deposit Handled in linear relationship, still can be according to region current differential over the groundSize judge that the region whether there is Earth fault.
5. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
For the region, if earth fault is not present in the region, region is to earth-current resistive componentEqual to 0, region pair Earth-currentEqual to region to earth-current capacitive componentI.e.:
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If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-currentAdvanced region zero sequence Voltage
If earth fault occurs in the region, the region region is to earth-current resistive componentRegion is to earth-current It is region to earth-current resistive componentWith region to earth-current capacitive componentVector:
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Because region is to earth-current resistive componentAddition, make region to earth-currentWith region residual voltageBetween phase Potential difference changes, and region is to earth-currentAdvanced region residual voltageRelation no longer set up;
When earth fault occurs in power distribution network, the region in the region is detected to earth-currentWith region residual voltagePhase Poor θ, it can judge that the region whether there is earth fault according to the value of phase difference θ;
The region that earth fault region be present can be changed to earth-current resistive component taking human as the adjustment phase-to-ground voltage of power distribution network threeMake region to earth-currentWith region residual voltagePhase difference θ farther away from " region is to earth-currentAdvanced region zero Sequence voltage" relation, so as to more accurately judge to have the region of earth fault.
The region can also be directed to, when there is earth fault in power distribution network, artificial three phase-to-ground voltages for adjusting power distribution networkRegion before record adjustment voltage is to earth-currentWith region residual voltagePhase difference θ1And tune The region of detection after whole voltage is to earth-currentWith region residual voltagePhase difference θ2, calculate the changes delta θ of phase difference =θ21If the region of affiliated area is to earth-currentWith region residual voltagePhase difference variation delta θ it is larger, can Judge that the region has earth fault;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, " region is to earth-currentAdvanced region zero sequence Voltage" relation with regard to invalid, still, if the region three in the region relatively susceptance BEA、BEB、BECAsymmetric journey Degree is not serious, can be approximately considered that " region is to earth-currentAdvanced region residual voltage" relation still set up, also Being can be according to region to earth-currentWith region residual voltagePhase difference θ size or phase difference change judge described in Region whether there is earth fault.
6. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
During defined area, reduce regional extent in equipment quantity and/or reduce regional extent in circuit length, reduce region Three relatively susceptance BEA、BEB、BEC, by the region in regional extent to earth-current capacitive componentControl is in the range of very little;
When earth fault occurs in power distribution network, the region in the region is detected to earth-current
When earth fault is not present in the region, no Regional Economy three-phase voltage-to-groundHow to change, region To earth-current capacitive componentOr very little, and the region in earth fault region is not present to earth-current resistive componentAbout etc. In 0, thus in the absence of earth fault region region to earth-currentVery little;
When there is earth fault in the region, the region in the region is to earth-current resistive componentIncrease, the area in the region Domain is to earth-currentIt will increase therewith, region is to earth-currentSize can be with reflecting regional to earth-current resistive componentIt is big It is small;Can be according to region to earth-currentSize judge that the region whether there is earth fault;
Can by artificially adjust the phase-to-ground voltage of power distribution network three method increase exist earth fault region region it is electric over the ground Fluid resistance componentRegion be present between earth fault region and other normal regions to earth-current resistive component in increasingDifference Away from so as to more accurately judge the region that earth fault be present;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentSize, deposit In the region in earth fault region to earth-current resistive componentIt will have greatly changed, and the region in earth fault region be present To earth-currentAlso will have greatly changed;So can also be according to the region in the region to earth-currentThe size of change Judge that the region whether there is earth fault.
7. power distribution network local ground fault detection method according to claim 1, it is characterized in that:
The region in the region is detected to earth-currentWith region residual voltageBy region to earth-currentBe decomposed into parallel to Region residual voltageParallel componentWith perpendicular to region residual voltageVertical component
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Region is to earth-current resistive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith parallel to area Domain residual voltageParallel component
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Region is to earth-current capacitive componentIt can be analyzed to perpendicular to region residual voltageVertical componentWith parallel to area Domain residual voltageParallel component
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Region is to earth-currentIt is region to earth-current resistive componentTwo components and region to earth-current capacitive component's The sum of two components;
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If the region three in the region relatively susceptance BEA、BEB、BECIt is symmetrical, region is to earth-current capacitive componentIn advance The residual voltage in the regionThis time domain current parallel component over the groundWith region To earth-current capacitive componentIt is unrelated, only with region to earth-current resistive componentIt is relevant, and region current parallel component over the groundWith region to earth-current resistive componentProportional relation be present, i.e.,:(if region is to earth-current Resistive componentWith the residual voltage in regionBetween angle be θ, K=1/cos θ);So can be by the region in the region Current parallel component over the groundAs region to earth-current resistive componentFor judging that the region whether there is earth fault;
If the region three in the region relatively susceptance BEA、BEB、BECAsymmetry, region is to earth-current capacitive componentWith region Residual voltageNo longer must be vertical relation, parallel component of the region to earth-current capacitive componentIt is no longer equal to 0,Because region is to the parallel component of earth-current capacitive componentAddition, according to region current parallel over the ground ComponentJudge that the method for local ground failure increases uncertain factor;
But the if region three in the region relatively susceptance BEA、BEB、BECMeet one of following two conditions:
If the 1. relatively susceptance B of region threeEA、BEB、BECAsymmetric degree is not serious, and region is to earth-current capacitive component zero The parallel component in sequence voltage directionVery little;
2. the relatively susceptance B of region threeEA、BEB、BECValue very little, region is to earth-current capacitive componentVery little, so region pair Parallel component of the earth-current capacitive component in residual voltage directionAlso very little;
If meeting the two conditions, region current parallel component over the ground can be approximately consideredWith region to resistive point of earth-current AmountProportional relation be present, i.e.,:So still can be by the region in region current parallel component over the ground As region to earth-current resistive componentFor judging that the region whether there is earth fault;
Can by artificially adjust the phase-to-ground voltage of power distribution network three method increase exist earth fault region region it is electric over the ground Fluid resistance componentRegion current parallel component over the ground be present between earth fault region and other normal regions in increasingDifference Away from so as to more accurately judge the region that earth fault be present;
The residual voltage of artificial adjustment power distribution networkArtificially change the region in each region to earth-current resistive componentSize, deposit In the region in earth fault region to earth-current resistive componentIt will have greatly changed, and the region in earth fault region be present Current parallel component over the groundAlso will have greatly changed;So earth-current can also be put down according to the region in the region Row componentThe size of change judges that the region whether there is earth fault.
8. a kind of power distribution network local ground failure detector, it is characterized in that:
A region delimited in power distribution network, an equipment or one section of circuit can be only included in the region, phase can be included Company and some adjacent equipment and some sections of circuits;
The power distribution network local ground failure detector can detect the region in the region to earth-currentThe power distribution network Local ground failure detector includes current sensing means, synchronous signal device, data acquisition device, data processing equipment; The current sensing means supports the use with current transformer;
Whole electric currents acquisition region that the region is flowed into by detecting is as follows to the process of earth-current:
A, current sensing means is installed in each intersection in institute defined area and other regions;Described current sensing means is examined The electric current of survey both can be phase current or zero-sequence current;The current sensing means can detect the size of electric current;It is described Current sensing means can also receive the synchronizing signal from synchronous signal device, detect electric current by it is negative become positive zero crossing relative to The time difference of synchronizing signal, or detection electric current is relative to the phase difference of synchronizing signal;
B, the data acquisition device can gather the current data of each current sensing means detection, and the current data of collection is sent Data processing equipment;
C, the data processing equipment receives the current data from data acquisition device, by each electric current by flowing to inside region Direction vector is added, can obtain the region in the region to the size of earth-current and region to earth-current relative to synchronizing signal Phase difference;
It is as follows to the process of earth-current that region is obtained by the whole electric currents detected from the region inflow the earth in power distribution network:
A, between the equipment in the regional extent and the energized conductor and the earth of circuit with equipment being present, energized conductor is with setting Distribution capacity be present between standby ground;Grounding body is being installed greatly on the ground, connected between grounding body by wire to equipment, equipment Ground and the earth equipotential, the distribution capacity between distribution capacity i.e. electrical body and the earth between electrical body and equipment ground, The wire of equipment or line mutual-ground capacitor electric current by equipment between grounding body flows into the earth;Grounding body can only have one It is individual, it is possibility to have multiple;Equipment connecting wire between grounding body can there was only one, it is possibility to have more;
B, current sensing means is installed in each bar connecting wire in equipment between grounding body, the current sensing means can Detect the size of electric current;The current sensing means can also receive the synchronizing signal from synchronous signal device, detect electric current Become time difference of the positive zero crossing relative to synchronizing signal, or detection electric current relative to the phase difference of synchronizing signal by negative;
C, the data acquisition device gathers the current data of each current sensing means detection, and send the current data of collection to number According to processing unit;
D, the data processing equipment receives the current data from data acquisition device, by each electric current by the direction for flowing to the earth Vector addition, obtain phase of the region in the region to the size of earth-current and region to earth-current relative to synchronizing signal Difference;
The power distribution network local ground failure detector can utilize the region that detection obtains to earth-currentWill according to right The power distribution network local ground fault detection method described in any one claim in 1~7 is sought, judges that the region whether there is Earth fault.
9. power distribution network local ground failure detector according to claim 8, it is characterized in that:
The power distribution network local ground failure detector also includes voltage check device, and the voltage check device and voltage are mutual Sensor supports the use;The voltage check device can detect the size of voltage;The voltage check device can also be received and come from The synchronizing signal of synchronous signal device, detection voltage become time difference of the positive zero crossing relative to synchronizing signal, or detection electricity by negative Press the phase difference relative to synchronizing signal;
Detecting the method for the region residual voltage is:Utilize the opening that voltage check device detection threephase potential transformer is secondary The output of triangle can obtain the data of residual voltage;The voltage check device can detect the size and zero sequence electricity of residual voltage Press the time difference relative to synchronizing signal or phase difference;The data acquisition device can gather the voltage check device detection Voltage data, and send the voltage data of collection to data processing equipment;The data processing equipment receives to be filled from data acquisition The voltage data put, obtain the residual voltage in the region size and residual voltage relative to synchronizing signal phase difference;
Detecting the method for three phase-to-ground voltage is:Utilize the secondary output electricity of voltage check device detection threephase potential transformer Pressure can obtain the data of three phase-to-ground voltages in the region;The voltage check device can detect the size of three phase-to-ground voltages With time difference of three phase-to-ground voltages relative to synchronizing signal or phase difference;The data acquisition device can gather the voltage inspection The voltage data of device detection is surveyed, and send the voltage data of collection to data processing equipment;The data processing equipment, which receives, to be come From the voltage data of data acquisition device, the size of three phase-to-ground voltages of acquisition and three phase-to-ground voltages are relative to synchronizing signal Phase difference;
The method for detecting the region residual voltage can also be:The number of three phase-to-ground voltages is detected first with voltage check device According to, and the voltage data that detection is obtained is sent to data processing equipment, data processing equipment is by three phase-to-ground voltages by relative The direction vector on ground is added, can obtain residual voltage size and residual voltage relative to synchronizing signal phase difference;
The data processing equipment can utilize the region that detection obtains to earth-currentWith region residual voltageOr utilize inspection The region measured is to earth-currentWith the phase-to-ground voltage of region threeAccording to any in claim 1~7 Power distribution network local ground fault detection method described in item claim, judges that the region whether there is earth fault.
10. power distribution network local ground failure detector according to claim 9, it is characterized in that:
The methods of first passing through offline inspection or on-line checking or calculating, obtain the relatively susceptance B of region threeEA、BEB、BEC;And will The relatively susceptance B of region threeEA、BEB、BECIt is stored in data processing equipment;
When earth fault occurs in system, the power distribution network local ground failure detector can utilize region to earth-current The phase-to-ground voltage of region threeWith the relatively susceptance B of region threeEA、BEB、BEC, according in claim 1~7 Power distribution network local ground fault detection method described in any one claim, judge that the region whether there is earth fault.
11. power distribution network local ground failure detector according to claim 9, it is characterized in that:
The methods of first passing through offline inspection or on-line checking or calculating, obtain region total susceptance B over the groundE;It is and region is total over the ground Susceptance BEIt is stored in data processing equipment;
When earth fault occurs in system, the region obtained using detection is to earth-currentRegion residual voltageWith region over the ground Total susceptance BE, according to the power distribution network local ground fault detection method described in any one of claim 1~7 claim, sentence The disconnected region whether there is earth fault.
12. the power distribution network local ground failure detector according to any one claim in claim 8~11, its It is characterized in:
The synchronizing signal that the synchronous signal device is sent can be a controlled single pulse signal, can be a fixed week The pulse signal of phase, it can also be a sine wave signal;The synchronizing signal can by wired, wireless way for transmitting, It can be transmitted by optical fiber;The synchronous signal device can utilize GPS second pulses generation synchronizing signal;
If the synchronizing signal is pulse signal, each voltage, current sensing means are all made with the pulse signal of synchronization For time reference point, such as:Using GPS second pulses generation synchronizing signal, each voltage, current sensing means are with the second of synchronization Pulse, in order to ensure to use the data in synchronization detection to participate in calculating, can examine each voltage, electric current as time reference Survey data and stamp time tag;If the synchronizing signal is AC signal, each voltage, current sensing means are all with same AC signal as reference signal, such as:Each voltage, current sensing means are all used as reference signal using A phase voltage signals.
13. the power distribution network local ground failure detector according to any one claim in claim 8~11, its It is characterized in:
Voltage check device can be arranged in the regional extent, the voltage at some position inside detection zone;Can also Voltage check device is arranged on outside the regional extent, what detection was connected with the region internal unit or circuit is located at area The voltage at some position outside the scope of domain, using the voltage inside the voltage zoning of region exterior, or directly by outside region The voltage in portion is as the voltage inside region.
14. the power distribution network local ground fault detection method according to any one claim in claim 8~11, its It is characterized in:
It is artificial to change the phase-to-ground voltage of region threeMethod include:Electricity is set between phase line and the earth Resistance, the access of resistance between three-phase phase line and the earth is controlled by three high-voltage switch gears respectively, determines to close according to ground fault condition Close wherein some switch;For neutral by arc extinction coil grounding system, the resistance in parallel with arc suppression coil is set, pressed off by height Close the input of control parallel resistance;For neutral by arc extinction coil grounding system, the resistance connected with arc suppression coil is set, by High-voltage switch gear controls the input and short circuit of series resistance;, can also be in arc blowout wire for neutral by arc extinction coil grounding system Secondary coil is set on circle, parallel resistance is attempted by the secondary coil of arc suppression coil, the throwing of parallel resistance is controlled by switch Cut;For neutral by arc extinction coil grounding system, change the inductance value of arc suppression coil;Only need to be when being grounded location determination in short-term Between change the phase-to-ground voltage of region three
15. a kind of power distribution network local ground fault detection system, it is characterized in that:
The power distribution network local ground fault detection system includes data syn-chronization detecting system, data acquisition communication system, data Background processing system;
The course of work of the power distribution network local ground fault detection system is as follows:
A, multiple regions delimited in power distribution network;
B, data syn-chronization detecting system can provide unified synchronizing signal to the current sensing means of distributing installation;Data syn-chronization Detecting system detects the size of each electric current using the current sensing means of distributing installation and each electric current by negative becomes positive zero crossing phase For the time difference of synchronizing signal, or each electric current of detection is relative to the phase difference of synchronizing signal;
C, data acquisition communication system can gather the current data of each current sensing means detection, and by the current data of collection It is sent to data background processing system;Data communication method can use the modes such as wire communication, optical-fibre communications, wireless telecommunications, Wireless telecommunications can use GPRS communication modes;
D, data background processing system utilizes the current data from data acquisition communication system, respectively for each region calculating area Domain is to earth-current
E, data background processing system is according to the power distribution network local ground described in any one claim in claim 1~14 Fault detection method or device methods described, using the region in each region to earth-currentData, respectively for each region decision It whether there is earth fault inside region, so as to realize the region for determining to have earth fault in numerous regions.
16. power distribution network local ground fault detection system according to claim 15, it is characterized in that:
Described power distribution network local ground fault detection system also includes voltage check device, is detected using voltage check device each The residual voltage in region or three phase-to-ground voltages;
Described power distribution network local ground fault detection system can include one or more voltage check devices, voltage detecting dress The voltage that bus is detected in transformer station can be arranged on by putting, or the electricity of circuit is detected in some switching station outside transformer station Press, or the voltage of circuit is detected on certain section of circuit;
Data syn-chronization detecting system can also provide unified synchronizing signal to the voltage check device of distributing installation;Data syn-chronization Detecting system can be using the size and voltage of the voltage for the voltage check device detection being arranged in power distribution network relative to synchronization The time difference of signal or phase difference;Data acquisition communication system can gather the voltage data of each voltage check device detection, and The voltage data of collection is sent to data background processing system;
Data background processing system is according to the voltage data from data collecting system, it is determined that the voltage data in each region;
Data background processing system can connect according to the distribution web area described in any one claim in claim 1~14 Method described in earth fault detection method or device, using the region in each region to earth-currentWith the phase-to-ground voltage of region threeData, or the region in each region is utilized to earth-currentWith region residual voltageData, it is directed to respectively It whether there is earth fault inside each region decision region, so as to realize the area for determining to have earth fault in numerous regions Domain.
17. power distribution network local ground fault detection system according to claim 16, it is characterized in that:
The power distribution network local ground fault detection system can also gather the state of related switch in power distribution network, by the shape of switch State is sent to data background processing system together with voltage, current data, the state by data background processing system according to switch Determine each region is currently in connected state with which voltage check device respectively, so as to determine respectively each region it is currently employed which The voltage data of individual voltage check device detection.
18. the power distribution network local ground fault detection system according to any one claim in claim 15~17, It is characterized in that:
Described power distribution network local ground fault detection system can be combined with electrical power distribution automatization system, utilize electrical power distribution automatization system Terminal unit detection voltage data, current data and the on off state of distributing installation, are filled using the communication of electrical power distribution automatization system Put and detection data are sent to power distribution network local ground fault detection system, realize the Earth design function of power distribution network;Match somebody with somebody The result for being grounded positioning can be sent in electrical power distribution automatization system by power network Earth design system, to quickly isolate ground connection Fault zone creates conditions;The function of described power distribution network local ground fault detection system can also be directly merged into distribution In automated system, the repertoire of power distribution network local ground fault detection system is completed by electrical power distribution automatization system.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109375011A (en) * 2018-10-15 2019-02-22 上海电力学院 A kind of detection method of novel microgrid failure
CN109917231A (en) * 2019-04-09 2019-06-21 国网四川省电力公司电力科学研究院 The system and method for electric energy metering device metering performance is obtained under singlephase earth fault
WO2020140583A1 (en) * 2019-01-04 2020-07-09 中国南方电网有限责任公司超高压输电公司梧州局 Detection device and method for distinguishing branches having capacitive or resistive instantaneous ground faults
WO2020181982A1 (en) * 2019-03-12 2020-09-17 南京南瑞继保电气有限公司 Distributed grounding line selection system and method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109375011A (en) * 2018-10-15 2019-02-22 上海电力学院 A kind of detection method of novel microgrid failure
WO2020140583A1 (en) * 2019-01-04 2020-07-09 中国南方电网有限责任公司超高压输电公司梧州局 Detection device and method for distinguishing branches having capacitive or resistive instantaneous ground faults
WO2020181982A1 (en) * 2019-03-12 2020-09-17 南京南瑞继保电气有限公司 Distributed grounding line selection system and method
CN109917231A (en) * 2019-04-09 2019-06-21 国网四川省电力公司电力科学研究院 The system and method for electric energy metering device metering performance is obtained under singlephase earth fault
CN109917231B (en) * 2019-04-09 2021-05-14 国网四川省电力公司电力科学研究院 System and method for acquiring metering performance of electric energy metering device under single-phase earth fault

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