CN103728532B - One-phase earthing failure in electric distribution network judgement and localization method - Google Patents

One-phase earthing failure in electric distribution network judgement and localization method Download PDF

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Publication number
CN103728532B
CN103728532B CN201310731710.7A CN201310731710A CN103728532B CN 103728532 B CN103728532 B CN 103728532B CN 201310731710 A CN201310731710 A CN 201310731710A CN 103728532 B CN103728532 B CN 103728532B
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zero
power distribution
sequence
current
line feed
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CN103728532A (en
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许永军
叶志峰
杜东威
刘敏
李俊晨
吴灿碧
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CYG Sunri Co Ltd
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CYG Sunri Co Ltd
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Abstract

The invention discloses a kind of one-phase earthing failure in electric distribution network judgement and localization method, when the technical problem that solve is power distribution network generation singlephase earth fault, judge accurately, fast fault section. Method of the present invention, comprises the following steps: on the circuit of power distribution network, block switch is set, configures power distribution automation line feed terminals on block switch, power distribution automation line feed terminals is set up network service; Power distribution automation line feed terminals judges line single phase grounding failure, judges that Single-phase Ground Connection Failure is positioned at the block switch adjacent sections at this power distribution automation line feed terminals place. The present invention compared with prior art, detect singlephase earth fault by each power distribution automation line feed terminals judgement, each power distribution automation line feed terminals is set up network service each other, interaction fault judges information mutually, the particular location of the localization of faults, can determine fast fault zone, reduce fault handling time, improve power supply reliability.

Description

One-phase earthing failure in electric distribution network judgement and localization method
Technical field
The present invention relates to the judgement of a kind of determination methods of distribution network failure, particularly a kind of singlephase earth faultWith localization method.
Background technology
10kV electrical power distribution automatization system (power distribution network, the system) major part of China is isolated neutral systemOr neutral by arc extinction coil grounding system, in the time there is singlephase earth fault, the electric current of trouble point is very little,And it is symmetrical that the line voltage between three-phase still keeps, and the power supply of load is not affected, therefore code regulationCan continue to move 1~2 hour, and needn't trip immediately. But singlephase earth fault perfects phase after occurringVoltage will raiseDoubly, under individual cases, earthing capacitance current may cause that trouble point electric arc leaps, instantaneousThere is overvoltage, cause insulating breakdown, be further development of or multipoint earth faults at 2, so, standardFind really, fast earth point fault, and fix a breakdown, significant to the safe operation of power distribution network.
The main stream approach that prior art is processed singlephase earth fault is first to select fault wire by line selection apparatusRoad, or by the method for " examination is drawn ", determine faulty line. After faulty line is determined, with the side of line walkingMethod finds trouble point.
For isolated neutral system and compensated distribution network, in the time there is singlephase earth fault, institute showsFeature identical to some extent: isolated neutral system is occurring when singlephase earth fault, the zero sequence flowing through in fault elementElectric current equals the non-fault element capacitive earth current of total system sum, the actual direction of capacitive character reactive power byLine flows is to bus, and the zero-sequence current in faulty line equals the capacitive earth current of itself, capacitive character withoutThe direction of merit power flows to circuit by bus. For compensated distribution network, due to the work of arc suppression coilWith, greatly reduced the fault current of trouble point, the in the situation that of overcompensation, the capacitive character of faulty line withoutMerit power direction is also identical with non-fault line.
In addition, after judging faulty line, find rapidly trouble point also particularly important. But distributionNetting twine road is intricate, and some circuits reach tens kms; Some overhead transmission lines are crossed over mountain after mountain difficult in maintenance,Some all fronts are built on stilts, have plenty of cable aerial mixed line. Once breaking down, overhead transmission line searches difficulty,Particularly in the time of circuit generation single-phase earthing, because trouble point is difficult to determine, while often having incured loss through delay accident treatmentMachine, causes fault to expand, and is further development of phase fault, or damages electrical equipment.
Summary of the invention
The object of this invention is to provide a kind of one-phase earthing failure in electric distribution network judgement and localization method, solveWhen technical problem is power distribution network generation singlephase earth fault, judge accurately, fast fault section.
The present invention is by the following technical solutions: a kind of one-phase earthing failure in electric distribution network judgement and localization method, bagDraw together following steps:
One, on the circuit of power distribution network, block switch is set, on each block switch, configures power distribution automation feedbackLine terminal, each power distribution automation line feed terminals is passed through fiber optic Ethernet or EPON network and the network switch and is connectedConnect, set up network service each other;
Two, the data acquisition unit of power distribution automation line feed terminals, obtains the residual voltage 3U of this circuit0With zeroOrder electric current 3I0Primary signal, obtain digital quantity through analog/digital conversion, power distribution automation line feed terminalsDigital quantity is carried out fourier algorithm calculating by cpu data processing unit, calculates this for isolated neutral systemThe residual voltage 3U of circuit0With zero-sequence current 3I0Vector, for neutral by arc extinction coil grounding system meterCalculate zero sequence the 5th harmonic current 3I05Vector;
Three,, to described isolated neutral system, cpu data processing unit uses zero sequence steady-state quantity criterion to carry outJudgement, by the mould of zero-sequence current vector | 3I0| with zero sequence overcurrent protection definite value IsetCompare cpu data placeReason unit uses the judgement of directional element criterion, relatively residual voltage 3U0With zero-sequence current 3I0Phase place; Simultaneously fullFoot 3I0>Iset, zero-sequence current 3I0Hysteresis residual voltage 3U090 °, judge that this circuit is singlephase earth fault;Described zero sequence overcurrent protection definite value Iset=k·3I0i, k is safety coefficient, 1 < k≤2,3I0iFor circuit normalZero-sequence current in situation;
To described neutral by arc extinction coil grounding system, cpu data processing unit uses 5 subharmonic criterions to enterRow judgement, by the mould of zero sequence the 5th harmonic current vector | 3I05| with zero sequence the 5th harmonic current definite value Iset5Compare, cpu data processing unit is to residual voltage 3U0With zero-sequence current 3I0Use transient criterion to sentenceDisconnected, head half wave phase of transient zero-sequence current and residual voltage on alternative route; 3I05>Iset5, or transient state zeroOrder electric current 3I0With residual voltage 3U0First half-wave single spin-echo, judge that this circuit is singlephase earth fault; InstituteState zero sequence the 5th harmonic current definite value Iset5=k·3I05i, k is safety coefficient, 1 < k≤2,3I05iFor lineRoad zero sequence the 5th harmonic current under normal circumstances;
Four, each power distribution automation line feed terminals (FTU) judgement meets following fault location condition 1 or faultLocation condition 2, judges that Single-phase Ground Connection Failure is positioned at the block switch at this power distribution automation line feed terminals placeAdjacent sections, block switch adjacent sections is the circuit being connected with this block switch;
Described fault location condition 1, this power distribution automation line feed terminals is judged singlephase earth fault, this distributionThe mains side power distribution automation line feed terminals of automation line feed terminals judge singlephase earth fault or mains side withoutPower distribution automation line feed terminals, the load side power distribution automation line feed terminals of this power distribution automation line feed terminals does not haveJudge earth fault or load side without power distribution automation line feed terminals, Single-phase Ground Connection Failure is positioned at this pointThe load side line that Duan Kaiguan is connected;
Described fault location condition 2, this power distribution automation line feed terminals is not judged singlephase earth fault, power supplySide power distribution automation line feed terminals is judged singlephase earth fault, and Single-phase Ground Connection Failure is positioned at this block switchThe mains side circuit being connected.
The circuit of the power distribution network of the inventive method is 10kV circuit.
The step 1 of the inventive method arranges block switch on a circuit of power distribution network.
The step 3 of the inventive method, centering point isolated neutral system meets the mould of zero-sequence current vector simultaneously|3I0| > zero sequence overcurrent protection definite value Iset, zero-sequence current 3I0Hysteresis residual voltage 3U090 °, the duration is large0.1-3 second, judge that this circuit is singlephase earth fault.
The step 3 of the inventive method, centering point compensated distribution network, transient zero-sequence current and zeroThe first half-wave single spin-echo duration of sequence voltage is greater than 0.1-3 second, is judged as and meets transient criterion.
The step 3 of the inventive method, centering point compensated distribution network, zero sequence the 5th harmonic wave electricityThe mould of flow vector | 3I05| > zero sequence the 5th harmonic current definite value Iset5, or meet transient criterion, while continuingBetween be greater than 0.1-3 second, judge that this circuit is singlephase earth fault.
The step 3 of the inventive method, centering point compensated distribution network, cpu data processing unit willThe residual voltage of circuit and zero-sequence current buffer memory 6 cycle sampled datas, as the residual voltage 3U of circuit0EffectivelyValue is greater than the moment of 15V, records this current sampling point, then from current sampling point starts to search forward 6The zero-sequence current 3I of individual cycle0Sampled data, finds zero-sequence current maximum 3I0maxSampled point, extract shouldThe sampled value residual voltage 3U at place0Nsam, relatively 3I0maxAnd 3U0NsamPhase place, symbol is contrary, judgement shouldThere is earth fault in circuit.
The step 2 of the inventive method, the sampling number of every cycle of data acquisition unit is for being no less than 24 points.
The sampling number of every cycle of the data acquisition unit of the inventive method is 32.
The present invention compared with prior art, detects single-phase connecing by each power distribution automation line feed terminals FTU judgementEarth fault, each power distribution automation line feed terminals FTU sets up network service each other, mutually mutual eventBarrier judgement information, the particular location of the localization of faults, can determine fault zone fast, reduces troubleshootingTime, improve power supply reliability.
Brief description of the drawings
Fig. 1 is isolated neutral system zero-sequence direction component schematic diagram.
Fig. 2 is isolated neutral system singlephase earth fault decision logic figure of the present invention.
Fig. 3 is " transient " of the present invention criterion schematic diagram.
Fig. 4 is compensated distribution network singlephase earth fault decision logic figure of the present invention.
Fig. 5 is singlephase earth fault of the present invention location schematic diagram.
Detailed description of the invention
Below in conjunction with drawings and Examples, the present invention is described in further detail. Power distribution network of the present invention is single-phaseEarth fault judgement and localization method, the power distribution automation line feed terminals of employing 10kV electrical power distribution automatization systemFTU judges singlephase earth fault, and by means of communication network, realizes the location to singlephase earth fault. LogicalCommunication network is fiber optic Ethernet or EPON network.
10kV power distribution network great majority are neutral point non-direct grounding system, in the time there is singlephase earth fault, and zeroOrder electric current is less, particularly compensated distribution network, and due to the compensating action of arc suppression coil, zero sequence electricityThe steady-state quantity determination methods single by prior art flow more difficult seizure, so can not accurately judge single-phase earthingFault. Method of the present invention, for isolated neutral system, neutral by arc extinction coil grounding system, is dividedSinglephase earth fault judgement and localization method are you can well imagine out.
One, isolated neutral system singlephase earth fault determination methods
(1) general principle
When isolated neutral system generation singlephase earth fault, fault signature is: the zero sequence electricity of faulty lineStream equals to remove outside faulty line, system-wide non-fault line element capacitive earth current sum; Fault wire90 ° of the zero-sequence current hysteresis residual voltages on road, 90 ° of the leading residual voltages of zero-sequence current of non-fault line. InstituteWith, centering point isolated neutral system, power distribution automation line feed terminals FTU adopts " zero sequence steady-state quantity "+" sideTo element " criterion judges singlephase earth fault. " zero sequence steady-state quantity " refers to that the zero-sequence current of circuit is greater than a certainWhen definite value, be judged as this circuit earth fault has occurred. " directional element " refers to the zero sequence by alternative routeThe phase place of voltage and zero-sequence current is determined whether ground connection of circuit.
1, " zero sequence steady-state quantity " criterion
3I0>Iset(1)
When the mould (actual measurement zero-sequence current) of the zero-sequence current vector of circuit | 3I0| be greater than IsetWhen definite value, be judged to beThere is singlephase earth fault in this circuit, wherein, and IsetFor the zero sequence overcurrent protection definite value of this circuit, it is scalarValue.
IsetAdjust need meet following formula:
3I-3I0i≥Iset>3I0i(2)
In formula (2), 3IFor the zero-sequence current under normal circumstances of all circuits on bus under faulty lineSum, 3I0iFor faulty line zero-sequence current under normal circumstances, the left-hand component 3I of formula (2)-3I0iForThe fault current of faulty line, IsetNeed be less than or equal to the fault current of faulty line, and be greater than this circuitZero-sequence current under normal circumstances, is expressed as:
Iset=k·3I0i(3)
In formula (3), k is safety coefficient, is taken as: 1 < k≤2.
2, " zero-sequence direction component (directional element) " criterion
Use zero-sequence direction component Do criterion to differentiate, zero-sequence direction component Do criterion is:
In formula (4), in bracket+10 ° ,-10 ° be worst error scope, 3I0For the zero sequence electricity of circuitStream, 3U0For the residual voltage of circuit. Meet the zero-sequence current 3I that formula (4) shows this circuit0Phase place lags behind zeroSequence voltage 3U090 °, there is singlephase earth fault in this circuit.
The active region of zero-sequence direction component Do positive direction as shown in Figure 1.
For isolated neutral system, comprehensive by " zero sequence steady-state quantity " and " directional element " two kinds of criterionsJudge singlephase earth fault, supplementing of " directional element " conduct " zero sequence steady-state quantity ", can be more perfect,Judge more exactly singlephase earth fault.
(2) isolated neutral system singlephase earth fault determination methods, adopts following steps:
1, obtain analog quantity and calculate the vector value of residual voltage and zero-sequence current
Obtain " zero sequence steady-state quantity " and the needed analog quantity information of " directional element " criterion, use data acquisitionCollection unit, the little converter of voltage and current of power distribution automation line feed terminals FTU inside, obtains this circuitResidual voltage 3U0With zero-sequence current 3I0Primary signal, through analog/digital conversion, analog input amount is turnedBe changed to digital quantity, as instantaneous sampling value, process single by the cpu data of power distribution automation line feed terminals FTUThe digital quantity of data acquisition unit output is carried out fourier algorithm calculating by unit's (vector calculation module), respectively meterCalculate the residual voltage 3U of this circuit0With zero-sequence current 3I0Vector (vector value), computing formula is respectively as follows:
3 U &CenterDot; 0 = 3 U 0 r + j 3 U 0 x = 2 N &Sigma; m = 1 N 3 U 0 ( m ) sin m 2 &pi; N + j 2 N &Sigma; m = 1 N 3 U 0 ( m ) cos m 2 &pi; N - - - ( 5 )
3 I &CenterDot; 0 = 3 I 0 r + j 3 I 0 x = 2 N &Sigma; m = 1 N 3 I 0 ( m ) sin m 2 &pi; N + j 2 N &Sigma; m = 1 N 3 I 0 ( m ) cos m 2 &pi; N - - - ( 6 )
The sampling number of every cycle that in formula (5), formula (6), N is data acquisition unit, for being not less than 24Point (N >=24), N=32 in the present embodiment implementation procedure, 3Uor is the real part of vectorial 3Uo, j is imaginary numberUnit, 3Uox is the imaginary part of vectorial 3Uo, 3Uo(m)The instantaneous sampling value of residual voltage at sampled point m place,3Ior is the real part of vectorial 3Io, and 3Iox is the imaginary part of vectorial 3Io, 3Io(m)That zero-sequence current is at sampled point m placeInstantaneous sampling value.
2, singlephase earth fault logic judgement
Cpu data processing unit is within each interrupt cycle, in conjunction with the residual voltage 3U obtaining in sampling calculating0With zero-sequence current 3I0Vector value, carry out logic judgement.
As shown in Figure 2, before the judgement of isolated neutral system singlephase earth fault, first set following definite valueCode:
D018: little current zero sequence protection is thrown and moved back, while dropping into little current zero sequence protection, singlephase earth fault judgementFunction drops into, and while exiting, does not carry out singlephase earth fault judgement.
D129: little current zero sequence directional element is thrown and moved back, while dropping into little current zero sequence directional element, " directional element "Criterion starts, while exiting, without " directional element " criterion.
D008: little current zero sequence current ration, this definite value is the zero sequence overcurrent in " zero sequence steady-state quantity " criterionProtection definite value Iset
D009: limit value when little current zero sequence, meet singlephase earth fault criterion perdurabgility, be just considered toBe real singlephase earth fault, the time limit value of adjusting is 0.1-3 second.
Cpu data processing unit uses " zero sequence steady-state quantity " criterion to judge, by zero-sequence current vectorMould (mould value) | 3I0| with little current zero sequence current ration d008 (zero sequence overcurrent protection definite value Iset) compare, when the mould of zero-sequence current vector | 3I0| the little current zero sequence current ration of > d008 (zero sequence overcurrent protection definite valueIset) time, record " zero sequence steady-state quantity " startup is masked as " 1 ", i.e. FLAG1=1; Work as 3I0The little electricity of <When stream zero-sequence current definite value d008, record " zero sequence steady-state quantity " startup is masked as " 0 ", i.e. FLAG1=0.
Cpu data processing unit is to residual voltage 3U0With zero-sequence current 3I0Use " directional element " criterion to sentenceDisconnected, relatively residual voltage 3U0With zero-sequence current 3I0Phase place, meeting zero-sequence direction component Do criterion is formula (4)Time, show the zero-sequence current 3I of this circuit0Phase place hysteresis residual voltage 3U090 °, record " directional element "Do action is masked as " 1 ", i.e. FLAG2=1; As residual voltage 3U0With zero-sequence current 3I0Do not meet zero sequence sideWhile being formula (4) to element Do criterion, record " directional element " Do action is masked as " 0 ", i.e. FLAG2=0.
Be 1 o'clock at FLAG1 and FLAG2, and the duration is greater than 0.1-3 second in the little current zero sequence time limit simultaneouslyWhen definite value d009, judge that this circuit is singlephase earth fault.
Two, neutral by arc extinction coil grounding system single-phase earth fault determination methods
Neutral by arc extinction coil grounding system, power distribution automation line feed terminals FTU employing " 5 subharmonic "+" transient " criterion judges singlephase earth fault.
(1) general principle
1, " 5 subharmonic " criterion
In neutral by arc extinction coil grounding system, owing to having adopted the overcompensation of arc suppression coil at neutral point,Faulty line zero-sequence current is very little, cannot adopt " zero sequence steady-state quantity " to judge. But, through extinguishing arc lineCircle earthed system is occurring after singlephase earth fault, and the 5th harmonic wave (5 subharmonic) content of each circuit increasesVery fast, its distribution in electrical network is similar to the distribution of fundamental wave zero sequence electric current. When singlephase earth fault, faultThe zero sequence 5 subharmonic current content of circuit approximate removes the system-wide non-fault element zero of faulty line itselfOrder 5 subharmonic current sums. As shown in Figure 3, for zero sequence 5 subharmonic of faulty line, due to extinguishing arcCoil induction reactance is: 5 ω Lk, system capacitive reactance is:So, in system, flow out through non-fault line elementCapacitance current be faradic 25 times of arc suppression coil, the existence of arc suppression coil is almost to singlephase earth faultTime zero sequence 5 subharmonic do not affect, so, for neutral by arc extinction coil grounding system, can adoptJudge by zero sequence 5 subharmonic (5 subharmonic) criterion. 5 subharmonic criterions are:
3I05>Iset5(7)
When the mould (actual measurement zero sequence the 5th harmonic current) of zero sequence the 5th harmonic current vector of circuit | 3I05|>Iset5When definite value, be judged to be this circuit singlephase earth fault has occurred, wherein Iset5For the zero sequence of this circuitThe 5th (zero sequence 5 times) harmonic current definite value is scalar value.
Iset5Adjusting of definite value needs to meet following formula:
3I05Σ-3I05i≥Iset5>3I05i(8)
In formula (8), 3I05ΣFor the zero sequence under normal circumstances of all circuits on bus under faulty line 5 timesHarmonic current sum, 3I05iFor faulty line zero sequence 5 subharmonic currents under normal circumstances, a left side for formula (8)Limit part 3I05Σ-3I05iZero sequence 5 subharmonic currents while being faulty line fault, Iset5Need be less than or equal toZero sequence 5 subharmonic currents when faulty line fault, and be greater than this circuit zero sequence under normal circumstances 5 timesHarmonic current, is expressed as:
Iset5=k·3I05i(9)
In formula (9), k is safety coefficient, is taken as: 1 < k≤2.
2, " transient " criterion
If do not meet formula (7), can also use the judgement of transient criterion. Connect through arc suppression coil for neutral pointGround system, the principle of " transient " criterion is: the event of neutral by arc extinction coil grounding system generation single-phase earthingWhen barrier, transient zero-sequence current 3I on faulty line0With residual voltage 3U0First half-wave single spin-echo, non-fault wireOn road, transient zero-sequence current is identical with head half wave phase of residual voltage.
For neutral by arc extinction coil grounding system, comprehensive by " 5 subharmonic " and " transient " two kinds of criterionsClose judgement singlephase earth fault, both supplement mutually, can be more perfect, judge more exactly single-phase connecingEarth fault.
(2) neutral by arc extinction coil grounding system single-phase earth fault determination methods, adopts following steps:
1, obtain analog quantity information and be converted to digital quantity
(1) obtain the needed analog quantity information of " 5 subharmonic " criterion, with data acquisition unit, joinThe little converter of electric current of electric automation line feed terminals FTU inside, obtains the zero-sequence current 3I of this circuit0FormerBeginning signal, through analog/digital conversion, is converted to digital quantity by analog input amount, as instantaneous sampling value, byThe cpu data processing unit (vector calculation module) of power distribution automation line feed terminals FTU is by data acquisition listThe digital quantity of unit's output carries out fourier algorithm calculating, calculates zero sequence 5 subharmonic current 3I05Vector (vectorValue), computing formula is as follows:
3 I &CenterDot; 05 = 3 I 05 r + j 3 I 05 x = 2 N &Sigma; m = 1 N 3 I 0 ( m ) sin m 10 &pi; N + j 2 N &Sigma; m = 1 N 3 I 0 ( m ) cos m 10 &pi; N - - - ( 10 )
In formula (10), the sampling number of every cycle that N is data acquisition unit, for being not less than 24 point (N>=24), N=32 in the present embodiment implementation procedure. 3Io5 is zero-sequence current 5 subharmonic vectors, 3Io5rBe toThe real part of amount 3Io5,3Io5xBe the imaginary part of vectorial 3Io5, j is imaginary unit, 3Io(m)For zero-sequence current is being adoptedThe instantaneous sampling value at sampling point m place.
(2), obtain the needed analog quantity of " transient " criterion, to residual voltage 3U0With zero-sequence current 3I0Transient sampling, with data acquisition unit, i.e. voltage and the electricity of power distribution automation line feed terminals FTU insideFlow little converter, obtain the residual voltage 3U of this circuit0With zero-sequence current 3I0Primary signal. Data acquisitionUnit is not less than the sampling rate of 24 by every cycle, the present embodiment is by every cycle 32 point samplings, through simulation/Digital translation, is converted to digital quantity by analog input amount, as instantaneous sampling value.
As shown in Figure 3, for catching transient characterisitics, cpu data processing unit is by the residual voltage of circuit and zero sequenceElectric current buffer memory 6 cycle sampled datas. As the residual voltage 3U of this circuit0Virtual value be greater than moment of 15V,Record this current sampling point, then the zero-sequence current 3I of 6 cycles from current sampling point starts to search forward0Sampled data, finds zero-sequence current maximum 3I0maxSampled point, record zero-sequence current maximum 3I0maxPositionThe sampled point counting Nsam putting, then extract 3U0At the sampled value 3U at Nsam place0Nsam, last, relatively 3I0maxAnd 3U0NsamSymbol (phase place), if symbol is contrary, one is positive number, one is negative, judgement shouldThere is earth fault in circuit; If symbol is identical, be positive number entirely or be negative entirely, judge this circuit notThere is earth fault.
2, singlephase earth fault logic judgement
Cpu data processing unit, within each interrupt cycle, carries out patrolling of " 5 subharmonic " and " transient "Collect judgement.
As shown in Figure 4, before the judgement of neutral by arc extinction coil grounding system single-phase earth fault, first setFollowing definite value code:
D500: zero sequence 5 subharmonic protections are thrown and moved back, and while dropping into zero sequence 5 subharmonic protection, " 5 subharmonic " sentencedAccording to input, while exiting, " 5 subharmonic " criterion exits.
D501: zero sequence transient based protection is thrown and moved back, while dropping into zero sequence transient based protection, " transient " criterion drops into,While exiting, " transient " criterion exits.
D502: zero sequence 5 subharmonic definite values, this definite value is the zero sequence 5 subharmonic electricity in " 5 subharmonic " criterionStream definite value Iset5
D503: zero-sequenceprotection time delay definite value, meet singlephase earth fault criterion perdurabgility, be just considered toReal singlephase earth fault, singlephase earth fault criterion delayed setting is 0.1-3 second.
Cpu data processing unit uses " 5 subharmonic " criterion to judge, by zero sequence the 5th harmonic wave electricityThe mould (mould value) of flow vector | 3I05| with zero sequence 5 subharmonic definite value d502 (zero sequence the 5th harmonic current definite valueIset5) compare, when the mould of zero sequence the 5th harmonic current vector | 3I05| > zero sequence 5 subharmonic definite value d502(zero sequence the 5th harmonic current definite value Iset5) time, record " 5 subharmonic " startup is masked as " 1 ",FLAG1=1; Work as 3I05When < d502 definite value, record " 5 subharmonic " startup is masked as " 0 ", i.e. FLAG1=0.
Cpu data processing unit is to residual voltage 3U0With zero-sequence current 3I0Use the judgement of " transient " criterion,Work as 3U0And 3I0Meet " transient " criterion, i.e. transient zero-sequence current 3I0With residual voltage 3U0First half-waveSingle spin-echo, and duration while being greater than d503 time delay definite value, meet " transient " criterion, and record " temporarilyState amount " action be masked as " 1 ", i.e. FLAG2=1, works as 3U0And 3I0While not meeting " transient " criterion,Record " transient " action is masked as " 0 ", i.e. FLAG2=0.
When FLAG1 or FLAG2 equal 1, and the duration is greater than 0.1-3 zero-sequenceprotection second time delay definite value d503Time, judge that this circuit is singlephase earth fault.
Three, isolated neutral system and neutral by arc extinction coil grounding system single-phase earth fault location
(1) general principle
On a 10kV circuit in power distribution network, be provided with multiple block switches, these block switches are by one10kV circuit is divided into several sections, on each block switch of a 10kV circuit, configures a station power distributionAutomation line feed terminals FTU, each power distribution automation line feed terminals FTU is by fiber optic Ethernet or EPON netNetwork is connected with the network switch, sets up the communication of network each other.
FTU gathers the residual voltage 3U of this block switch present position circuit0With zero-sequence current 3I0, for neutralityPoint isolated neutral system, neutral by arc extinction coil grounding system, adopt different singlephase earth fault criterions,Judge each block switch place whether singlephase earth fault has occurred. Each power distribution automation line feed terminals FTU willWhether what judge is the result of singlephase earth fault, with the transformer substation case GOOSE towards general objectMessage format sends to other power distribution automation line feed terminals FTU in consolidated network, each power distribution automation feeder lineTerminal FTU is according to the own singlephase earth fault judged result to present position, in conjunction with what obtain from networkThe singlephase earth fault judged result of other power distribution automation line feed terminals FTU, carries out comprehensive analysis and judgement,Determine the particular location of Single-phase Ground Connection Failure. Like this, in the time of a 10kV circuit generation singlephase earth fault,Use method of the present invention, can not only know that singlephase earth fault has occurred which bar circuit, can also know single-phaseEarth fault is specifically positioned at which position of this circuit.
The GOOSE of each power distribution automation line feed terminals FTU opens into signal definition as table 1, and GOOSE outputs letterNumber definition as table 2.
Table 1GOOSE opens into signal
Table 2GOOSE outputs signal
GOOSE outputs empty terminal title Remarks
This position ground signalling is outputed This block switch place circuit whether output by ground signalling
Block signal is outputed This block switch place block signal is outputed
Described comprehensive analysis and judgement are: it is fixed that each power distribution automation line feed terminals FTU judgement meets following faultPosition condition 1 or fault location condition 2, judge that Single-phase Ground Connection Failure is positioned at this power distribution automation line feed terminalsThe block switch adjacent sections at place. Block switch adjacent sections is the circuit being connected with this block switch.
Fault location condition 1, this power distribution automation line feed terminals is judged (detecting) singlephase earth fault,The mains side power distribution automation line feed terminals of this power distribution automation line feed terminals judges that (detecting) is single-phase to be connectEarth fault or mains side be without power distribution automation line feed terminals, the load side distribution of this power distribution automation line feed terminalsAutomation line feed terminals does not judge (detecting) earth fault or load side is whole without power distribution automation feeder lineEnd, Single-phase Ground Connection Failure is positioned at the load side line that this block switch is connected.
Fault location condition 2, this power distribution automation line feed terminals is not judged (detecting) singlephase earth fault,Mains side power distribution automation line feed terminals is judged (detecting) singlephase earth fault, Single-phase Ground Connection FailureBe positioned at the mains side circuit that this block switch is connected.
(2) isolated neutral system and neutral by arc extinction coil grounding system single-phase earth fault location,Adopt following steps:
1, configuration frame
As shown in Figure 5, a 10kV circuit of the A of transformer station of the present embodiment through 5 block switch FD1,FD2, FD3, FD4, FD5 are connected with the B of transformer station, have formed " a handing in hand " circuit, Qi ZhongfenUnder Duan Kaiguan 3FD3 normal condition, be off-state, be called again interconnection switch. 5 block switches configure respectively5 station power distribution automation line feed terminals FTU1, FTU2, FTU3, FTU4, FTU5, each FTU gather bearThe line zero sequence voltage 3U of the block switch present position of duty0With zero-sequence current 3I0. 5 station power distribution automation feeder linesTerminal FTU is based upon in same network by fiber optic Ethernet, sets up each other by the network switchCommunication connection.
2, singlephase earth fault judgement detects
5 station power distribution automation line feed terminals FTU1, FTU2, FTU3, FTU4, FTU5 are for different neutralityPoint earthing mode adopts different singlephase earth fault criterions, in the time being isolated neutral system, adopts " steadyState amount "+" directional element " criterion, in the time being neutral by arc extinction coil grounding system, " 5 times are humorous in employingRipple "+" transient " criterion, judge each block switch place whether singlephase earth fault has occurred. Work as FTUWhile having there is singlephase earth fault in the block switch place that judges place, record " this position ground signalling is outputed "GOOSE output signal for " 1 ", otherwise the GOOSE of record " this position ground signalling is outputed " outputsSignal is " 0 ".
3, Single-phase Ground Connection Failure location
The associated letter of GOOSE of 5 station power distribution automation line feed terminals FTU1, FTU2, FTU3, FTU4, FTU5Number definition as table 3.
Table 3GOOSE correlation signal
In the time there is singlephase earth fault in F1 place between FD2 and FD3, fault current from ground connection flow through F1,FD2, FD1 be to the A of transformer station, as shown in the camber line 1 in Fig. 5, i.e. and block switch 1FD1, block switch 2FD2 all has fault current to flow through, and the GOOSE that is responsible for the FTU1 of these two block switch fault detects outputs letterNumber " this position ground signalling is outputed " is that the GOOSE of 1, FTU2 outputs signal " this position ground signalling is openedGo out " be that to output signal " this position ground signalling is outputed " be 0 for the GOOSE of 1, FTU3, FTU4 and FTU5.The GOOSE correlation signal of listing according to table 3, for FTU2, its mains side " open by mains side ground signallingEnter " be 1, because " FTU1: this position ground signalling is outputed " is 1, its load side " load side ground connectionSignal is opened into 01 " be 0, because " FTU3: this position ground signalling is outputed " is 0, meet fault location barPart 1, judges singlephase earth fault and is positioned at the sides adjacent of FTU2: load side. And for other FTU, bothDo not meet fault location condition 1, do not meet fault location condition 2 yet, so, singlephase earth fault not inThe block switch adjacent sections of other FTU.
In the present embodiment, it is direct current that 5 block switch FD1, FD2, FD3, FD4, FD5 adopt operating powerThe vacuum circuit breaker of 24V, 5 station power distribution automation line feed terminals FTU1, FTU2, FTU3, FTU4, FTU5To adopt model be PRS-3351 feed line automatization terminal, the network switch adopt working power be direct current 24V,Support the industrial ethernet switch of IEC61850 stipulations communication, adopt the Ver2.0 version journey of PRS-3351Order language is realized.
Power distribution automation line feed terminals FTU by the each block switch of circuit place is to block switch place circuit separatelyWhether there is singlephase earth fault and judged detection, and by communication network, realized power distribution automation feedbackInformation interaction between line terminal FTU is with shared, according to the principle mechanisms of singlephase earth fault location, finalRealize the accurate location of singlephase earth fault.
Method of the present invention is for 10kV isolated neutral with through the distribution network system of grounding through arc, pinTo distribution network complicated and changeable, propose singlephase earth fault and judged detection method, under every kind of method,By mutually supplementing of two kinds of criterions, realize more perfect fault judgement. Singlephase earth fault accuratelyJudgement, then single-phase fault fault location principle and mechanism, finally realized having of one-phase earthing failure in electric distribution networkEffect detects and accurately locates.
The strong intelligent grid overall framework of construction China proposing according to State Grid Corporation of China, information-based, digitalChange, automation, interactive be the outstanding feature feature of Chinese intelligent grid, can predict, along with intelligence is joinedThe propelling of power grid construction, the relay protection system of following intelligent distribution network based on local information is just being inheritedThe mature technology while of groundization protection, also by the development by means of informationization, digitizing technique, to mutual associationThe protection system development of the function synthesized in the wide scope of adjusting. One-phase earthing failure in electric distribution network of the present invention is sentencedBreak and localization method, to safeguarding reliability service, raising overhaul efficiency, the enhancing intelligent level tool of power distribution networkSignificant.

Claims (9)

1. one-phase earthing failure in electric distribution network judgement and a localization method, comprises the following steps:
One, on the circuit of power distribution network, block switch is set, on each block switch, configures power distribution automation feedbackLine terminal (FTU), each power distribution automation line feed terminals (FTU) is by fiber optic Ethernet or EPON networkBe connected with the network switch, set up network service each other;
Two, the data acquisition unit of power distribution automation line feed terminals (FTU), obtains the residual voltage of this circuit3U0With zero-sequence current 3I0Primary signal, obtain digital quantity through analog/digital conversion, power distribution automation feeder lineDigital quantity is carried out fourier algorithm calculating by the cpu data processing unit of terminal (FTU), do not connect for neutral pointGround system-computed goes out the residual voltage 3U of this circuit0With zero-sequence current 3I0Vector, for neutral point through extinguishing arcCoil earthed system calculates zero sequence the 5th harmonic current 3I05Vector;
Three,, to described isolated neutral system, cpu data processing unit uses zero sequence steady-state quantity criterion to carry outJudgement, by the mould of zero-sequence current vector | 3I0| with zero sequence overcurrent protection definite value IsetCompare cpu data placeReason unit uses the judgement of directional element criterion, relatively residual voltage 3U0With zero-sequence current 3I0Phase place; Simultaneously fullFoot 3I0>Iset, zero-sequence current 3I0Hysteresis residual voltage 3U090 °, judge that this circuit is singlephase earth fault;Described zero sequence overcurrent protection definite value Iset=k·3I0i, k is safety coefficient, 1 < k≤2,3I0iFor circuit normalZero-sequence current in situation;
To described neutral by arc extinction coil grounding system, cpu data processing unit uses 5 subharmonic criterions to enterRow judgement, by the mould of zero sequence the 5th harmonic current vector | 3I05| with zero sequence the 5th harmonic current definite value Iset5Compare, cpu data processing unit is to residual voltage 3U0With zero-sequence current 3I0Use transient criterion to sentenceDisconnected, head half wave phase of transient zero-sequence current and residual voltage on alternative route; 3I05>Iset5, or transient state zeroOrder electric current 3I0With residual voltage 3U0First half-wave single spin-echo, judge that this circuit is singlephase earth fault; InstituteState zero sequence the 5th harmonic current definite value Iset5=k·3I05i, k is safety coefficient, 1 < k≤2,3I05iFor lineRoad zero sequence the 5th harmonic current under normal circumstances;
Four, each power distribution automation line feed terminals (FTU) judgement meets following fault location condition 1 or faultLocation condition 2, judges that Single-phase Ground Connection Failure is positioned at the block switch at this power distribution automation line feed terminals placeAdjacent sections, block switch adjacent sections is the circuit being connected with this block switch;
Described fault location condition 1, this power distribution automation line feed terminals is judged singlephase earth fault, this distributionThe mains side power distribution automation line feed terminals of automation line feed terminals judge singlephase earth fault or mains side withoutPower distribution automation line feed terminals, the load side power distribution automation line feed terminals of this power distribution automation line feed terminals does not haveJudge earth fault or load side without power distribution automation line feed terminals, Single-phase Ground Connection Failure is positioned at this pointThe load side line that Duan Kaiguan is connected;
Described fault location condition 2, this power distribution automation line feed terminals is not judged singlephase earth fault, power supplySide power distribution automation line feed terminals is judged singlephase earth fault, and Single-phase Ground Connection Failure is positioned at this block switchThe mains side circuit being connected.
2. one-phase earthing failure in electric distribution network judgement according to claim 1 and localization method, its feature existsIn: the circuit of described power distribution network is 10kV circuit.
3. one-phase earthing failure in electric distribution network judgement according to claim 2 and localization method, its feature existsIn: described step 1 arranges block switch on a circuit of power distribution network.
4. one-phase earthing failure in electric distribution network judgement according to claim 1 and localization method, its feature existsIn described step 3, centering point isolated neutral system, meet the mould of zero-sequence current vector simultaneously | 3I0| > zeroOrder overcurrent protection definite value Iset, zero-sequence current 3I0Hysteresis residual voltage 3U090 °, the duration is greater than little electric currentWhen zero sequence, when limit value, judge that this circuit is singlephase earth fault, when described little current zero sequence, limit value is 0.1-3Second.
5. one-phase earthing failure in electric distribution network judgement according to claim 1 and localization method, its feature existsIn: described step 3, centering point compensated distribution network, transient zero-sequence current and residual voltageThe first half-wave single spin-echo duration, while being greater than zero-sequenceprotection time delay definite value, being judged as and meeting transient criterion,Described zero-sequenceprotection time delay definite value is 0.1-3 second.
6. one-phase earthing failure in electric distribution network judgement according to claim 4 and localization method, its feature existsIn: described step 3, centering point compensated distribution network, zero sequence the 5th harmonic current vectorMould | 3I05| > zero sequence the 5th harmonic current definite value Iset5, or meeting transient criterion, the duration is greater than zeroWhen order protection time delay definite value, judge that this circuit is singlephase earth fault, described zero-sequenceprotection time delay definite value is 0.1-3Second.
7. one-phase earthing failure in electric distribution network judgement according to claim 1 and localization method, its feature existsIn: described step 3, centering point compensated distribution network, cpu data processing unit is by zero of circuitSequence voltage and zero-sequence current buffer memory 6 cycle sampled datas, as the residual voltage 3U of circuit0Virtual value be greater thanIn the moment of 15V, record this current sampling point, then 6 cycles from current sampling point starts to search forwardZero-sequence current 3I0Sampled data, finds zero-sequence current maximum 3I0maxSampled point, extract adopting of this placeSample value residual voltage 3U0Nsam, relatively 3I0maxAnd 3U0NsamPhase place, symbol is contrary, judges that this circuit sends outGive birth to earth fault.
8. one-phase earthing failure in electric distribution network judgement according to claim 1 and localization method, its feature existsIn: described step 2, the sampling number of every cycle of data acquisition unit is for being no less than 24 points.
9. one-phase earthing failure in electric distribution network judgement according to claim 7 and localization method, its feature existsIn: the sampling number of every cycle of described data acquisition unit is 32.
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Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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CN111257700B (en) * 2020-03-31 2020-10-30 国网江苏省电力有限公司无锡供电分公司 Power distribution network single-phase earth fault positioning device and method based on edge calculation
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1397807A (en) * 2002-08-16 2003-02-19 华中科技大学 Method for positioning grounding failure region of feed line in low-current grounding system
JP2006280024A (en) * 2005-03-28 2006-10-12 Chugoku Electric Power Co Inc:The Apparatus automatic test system and apparatus automatic test method
JP2007159318A (en) * 2005-12-07 2007-06-21 Hokuriku Electric Power Co Inc:The Ground direction detector
CN101701998A (en) * 2009-11-19 2010-05-05 山东泰开自动化有限公司 Novel faulty line selection method in low current faulty grounding system
CN102608483A (en) * 2012-02-22 2012-07-25 北京航空航天大学 Direction diagnosing system of grounded fault of small current grounded distribution system
CN102628914A (en) * 2012-04-16 2012-08-08 安徽省电力公司合肥供电公司 Method for positioning grounding point of intelligent distribution line
CN102709889A (en) * 2012-05-29 2012-10-03 长园深瑞继保自动化有限公司 Self-healing method and self-healing system for faults of power distribution network
CN103293443A (en) * 2013-05-20 2013-09-11 国家电网公司 Overhead wire grounding fault locating method for power distribution network

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1397807A (en) * 2002-08-16 2003-02-19 华中科技大学 Method for positioning grounding failure region of feed line in low-current grounding system
JP2006280024A (en) * 2005-03-28 2006-10-12 Chugoku Electric Power Co Inc:The Apparatus automatic test system and apparatus automatic test method
JP2007159318A (en) * 2005-12-07 2007-06-21 Hokuriku Electric Power Co Inc:The Ground direction detector
CN101701998A (en) * 2009-11-19 2010-05-05 山东泰开自动化有限公司 Novel faulty line selection method in low current faulty grounding system
CN102608483A (en) * 2012-02-22 2012-07-25 北京航空航天大学 Direction diagnosing system of grounded fault of small current grounded distribution system
CN102628914A (en) * 2012-04-16 2012-08-08 安徽省电力公司合肥供电公司 Method for positioning grounding point of intelligent distribution line
CN102709889A (en) * 2012-05-29 2012-10-03 长园深瑞继保自动化有限公司 Self-healing method and self-healing system for faults of power distribution network
CN103293443A (en) * 2013-05-20 2013-09-11 国家电网公司 Overhead wire grounding fault locating method for power distribution network

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
基于FTU的小电流接地系统故障定位方法再研究;吴杰等;《继电器》;20041116;第32卷(第22期);第29-34页 *
基于谐波与首半波结合的单相接地选线分析与研究;殷培峰等;《自动化与仪器仪表》;20130831(第168期);第19-21页 *

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