CN103499771B - Phase selection method for double-circuit - Google Patents
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- CN103499771B CN103499771B CN201310469537.8A CN201310469537A CN103499771B CN 103499771 B CN103499771 B CN 103499771B CN 201310469537 A CN201310469537 A CN 201310469537A CN 103499771 B CN103499771 B CN 103499771B
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Abstract
The invention discloses a kind of phase selection method for double-circuit, the accuracy being to improve common-tower double-circuit lines phase selection will be solved the technical problem that.The present invention is by the following technical solutions: a kind of phase selection method for double-circuit, comprises the following steps: one, cross-line phase selection puts into and judges, protection device enters cross-line phase selection and judges；Two, meet three-phase low-impedance criterion to judge；Three, meet negative sequence voltage and judge criterion；Four, detection cross-line phase to phase fault, phase selection terminates.The present invention compared with prior art, based on various impedance characteristics, can the accuracy of significant increase phase selection when there is cross line fault; do not affected by passage; can be suitably used for pilot protection and distance protection, easily realize in microcomputer protective relay, it is ensured that the reliability of action and susceptiveness.
Description
Technical field
The method that the present invention relates to the protection of a kind of power system transmission line, particularly a kind of common-tower double-circuit lines cross-line event
The phase-selecting method of barrier.
Background technology
Along with electric network composition is increasingly tightr, transmission line corridor is fewer and feweri, has joint used double loop or even four loop lines
Generally it is employed.Owing to double-circuit line on same pole transmission line of electricity spacing is relatively near, may outlet cross line fault.Power system both at home and abroad
Operating experience show, cross line fault occurrence probability account for fault sum 10% to 20%.The choosing of common-tower double-circuit lines cross line fault
Being always a great problem of route protection mutually, prior art uses difference fluid element to carry out phase selection, in vertical and distance protection, poor
Fluid element phase selection cannot be used, and can not apply when passage is problematic.The phase-selecting method of prior art is choosing cross-line near-end
During fault can also accurate phase selection, but the most helpless to far-end fault, prior art phase selection is to the correct operation of protection and fault
Range finding produces a very large impact, and then totally unfavorable to the safe and stable operation of transformer station and transmission line of electricity.
Summary of the invention
It is an object of the invention to provide a kind of phase selection method for double-circuit, will solve the technical problem that it is to improve same bar
The accuracy of double-circuit line phase selection.
The present invention is by the following technical solutions: a kind of phase selection method for double-circuit, comprises the following steps:
One, cross-line phase selection puts into and judges, protection device will be gone zero sequence A phase to measure impedance Z a respectively, and be gone zero sequence B phase to measure resistance
Anti-Zb, Z go zero sequence C phase to measure impedance c, and the phase containing zero sequence A measures impedance Z Ka, and the phase containing zero sequence B measures impedance Z Kb, containing zero sequence C phase
Measuring impedance Z Kc, the phase containing zero sequence AB measures impedance Z Kab, and the phase containing zero sequence BC measures impedance Z Kbc, and Z phase Han zero sequence CA measures impedance
Kca and cross-line phase selection definite value ZkxspCompare, work as Za, the arbitrary phase in Zb, Zc, ZKa, ZKb, ZKc, ZKab, ZKbc, ZKca
Less than cross-line phase selection definite value ZkxspTime, protection device enters cross-line phase selection and judges；
Two, meet three-phase low-impedance criterion to judge, meet three-phase low-impedance criterion ZMax<0.1Zkxsp, or ZMax<1.2ZMin；
ZMaxFor Za, the maximum in Zb, Zc；ZMinFor Za, the minima in Zb, Zc；
Three, meet negative sequence voltage criterion to judge, meet negative sequence voltage criterion 3U2> 9V, U2For negative sequence voltage；
Four, detection cross-line phase to phase fault, cross-line phase to phase fault criterion is:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
It is biphase that protection device detects AB, BC, CA respectively, meets cross-line phase to phase fault criterion 1) to 5) in any one, sentence
Breaking as phase-to phase fault, phase selection terminates.
The method step three of the present invention is unsatisfactory for negative sequence voltage criterion, and travel direction element criterion filters；Or described step
Four are unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, travel direction element criterion filters (5)；Described directional element criterion is:UpolFor polarizing voltage,For each phase current；Three-phase meets directional element criterion, for three-phase
Fault, phase selection terminates.
The method three-phase of the present invention has a phase or biphase meets directional element criterion, for meeting the one of directional element criterion
Phase or phase to phase fault, phase selection terminates.
The method three-phase of the present invention is unsatisfactory for directional element criterion, and for reverse direction failure, phase selection terminates.
The method step two of the present invention is unsatisfactory for three-phase low-impedance criterion, carries out meeting single-phase fault impedance criterion and judges,
Single-phase fault impedance criterion is:
1), ZMin<0.5ZMax, or ZMin<0.1Zkxsp；
2), ZMin<0.5ZMid；
3), ZMid>0.1Zkxsp；
Meet the 1 of single-phase fault impedance criterion) to 3) item, detect phase to phase impedance minimum phase fault, use detection cross-line two
The cross-line phase to phase fault criterion of phase fault:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
It is biphase that device detects AB, BC, CA respectively, meets cross-line phase to phase fault criterion 1) to 5) in any one, it is judged that for
Phase-to phase fault, phase selection terminates.
It is biphase that the square law device of the present invention detects AB, BC, CA respectively, is unsatisfactory for cross-line phase to phase fault criterion 1) to 5) in
Any one, detects single phase impedance minimum phase fault, uses directional element criterion to filter, and directional element criterion is:UpolFor polarizing voltage,For each phase current；Meet directional element criterion, for single-phase event
Barrier, phase selection terminates.
The method of the present invention uses directional element criterion to filter, and is unsatisfactory for directional element criterion, uses detection cross-line biphase
The cross-line phase to phase fault criterion of fault, cross-line phase to phase fault criterion is:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
Meet cross-line phase to phase fault criterion 1) to 5) in any one, it is judged that for single phase impedance big or middle phase phase-to phase fault, choosing
Terminate mutually.
The method detection cross-line phase to phase fault of the present invention, is unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, do not select therefore
Barrier phase, phase selection terminates.
The method of the present invention carries out meeting single-phase fault impedance criterion and judges, is unsatisfactory for the 1 of single-phase fault impedance criterion) extremely
3) item, carries out meeting phase-to phase fault impedance criterion and judges, phase-to phase fault impedance criterion is:
1), ZMin<0.1Zkxsp, or ZMin<0.5ZMax；
2), ZMid<0.1Zkxsp, or ZMid<0.5ZMax；
Meet the 1 of phase-to phase fault impedance criterion) and 2) item, detect the medium and small phase fault of phase to phase impedance, use detection cross-line two
The cross-line phase to phase fault criterion of phase fault, cross-line phase to phase fault criterion is:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
Meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as the middle or small phase fault of phase to phase impedance, phase selection
Terminate.
The method detection cross-line phase to phase fault of the present invention, is unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, use direction
Element criterion filters the middle or small phase of phase to phase impedance, and directional element criterion is:UpolFor polarization electricity
Pressure,For each phase current；The middle or small phase of phase to phase impedance meets directional element criterion, it is judged that for the middle or small phase fault of phase to phase impedance, choosing
Terminate mutually.
The method of the present invention uses directional element criterion to filter the middle or small phase of phase to phase impedance, only phase in phase to phase impedance, meets
Directional element criterion, it is judged that for phase fault in phase to phase impedance, or the only little phase of phase to phase impedance meets directional element criterion, it is judged that for
The little phase fault of phase to phase impedance, phase selection terminates.
The method of the present invention uses directional element criterion to filter the middle or small phase of phase to phase impedance, is unsatisfactory for directional element criterion, then
For reverse direction failure, phase selection terminates.
The method of the present invention carries out meeting phase-to phase fault impedance criterion and judges, is unsatisfactory for the 1 of phase-to phase fault impedance criterion) and
2) item, carries out judging that end fault impedance criterion, end fault impedance criterion are:
1), A phase of impedance maximum, and ZKbc < 1.5ZMin；
2), B phase of impedance maximum, and ZKca < 1.5ZMin；
3), C phase of impedance maximum, and ZKab < 1.5ZMin；
4), ZMid<Zkxsp；
Meet the 1 of end fault impedance criterion), 2) or 3) item, add end fault impedance criterion 4) item, it is judged that meet end
End fault impedance criterion, detects the medium and small phase fault of phase to phase impedance, uses the cross-line phase to phase fault criterion of detection cross-line phase to phase fault,
Cross-line phase to phase fault criterion is:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
Meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as the middle or small phase fault of phase to phase impedance, phase selection
Terminate.
The cross-line phase to phase fault criterion of the method detection cross-line phase to phase fault of the present invention, is unsatisfactory for cross-line phase to phase fault criterion 1) extremely
5) item, uses directional element criterion to filter the middle or small phase of phase to phase impedance, and directional element criterion is:
UpolFor polarizing voltage,For each phase current；The middle or small phase of phase to phase impedance meets directional element criterion, it is judged that in phase to phase impedance,
Little phase fault, phase selection terminates.
The cross-line phase to phase fault criterion of the method detection cross-line phase to phase fault of the present invention, only phase in phase to phase impedance, meet
Directional element criterion, it is judged that for phase fault in phase to phase impedance, or the only little phase of phase to phase impedance meets directional element criterion, it is judged that for
The little phase fault of phase to phase impedance, phase selection terminates.
The method of the present invention surveys the cross-line phase to phase fault criterion of cross-line phase to phase fault, is unsatisfactory for directional element criterion, for instead
Direction fault, phase selection terminates.
The method of the present invention carries out judging end fault impedance criterion, is unsatisfactory for the 1 of end fault impedance criterion), 2) or
3) item, adds end fault impedance criterion 4) item, it is judged that it is unsatisfactory for end fault impedance criterion, the event mutually of detection single phase impedance minimum
Barrier, uses directional element criterion to filter, meets directional element criterion:For single-phase fault, choosing
Terminate mutually.
The method of the present invention uses directional element criterion to filter, and is unsatisfactory for directional element criterion, uses detection cross-line biphase
The cross-line phase to phase fault criterion of fault, cross-line phase to phase fault criterion is:
1), 3U2> 9V,
2), 3I2>0.125×3I1, I2For negative-sequence current, I1For forward-order current,
3),Uab1For biphase positive sequence voltage, IabFor biphase current,
4), ZKab < 1.5Za, and ZKab < 1.5Zb,
5),IaFor A phase current, IbFor B phase current；
Meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as single phase impedance big or middle phase phase-to phase fault,
Phase selection terminates.
The method of the present invention uses the cross-line phase to phase fault criterion of detection cross-line phase to phase fault, is unsatisfactory for cross-line phase to phase fault
Criterion 1) to 5) item, the unselected phase that is out of order, phase selection terminates.
The present invention compared with prior art, based on various impedance characteristics, can significant increase phase selection when there is cross line fault
Accuracy, do not affected by passage, can be suitably used for pilot protection and distance protection, easily realize in microcomputer protective relay,
Ensure that reliability and the susceptiveness of action.
Accompanying drawing explanation
Fig. 1 is the inventive method flow chart.
Detailed description of the invention
With embodiment, the present invention is described in further detail below in conjunction with the accompanying drawings.The meaning of the term of the present invention:
Za: go zero sequence A phase to measure impedance；
Zb: go zero sequence B phase to measure impedance；
Zc: go zero sequence C phase to measure impedance；
ZKa: the phase containing zero sequence A measures impedance；
ZKb: the phase containing zero sequence B measures impedance；
ZKc: the phase containing zero sequence C measures impedance；
ZKab: the phase containing zero sequence AB measures impedance；
ZKbc: the phase containing zero sequence BC measures impedance；
ZKca: the phase containing zero sequence CA measures impedance；
ZMax: the maximum in Za, Zb, Zc；
ZMin: the minima in Za, Zb, Zc；
ZMid: the intermediate value in Za, Zb, Zc；
Zkxsp: cross-line phase selection definite value, fix and take the 60% of total track length positive sequence impedance.
Above-mentioned Za, Zb, Zc, ZKa, ZKb, ZKc, ZKab, ZKbc, ZKca, be for protective relaying device (protection device or
Device) the whole piece transmission line of electricity (circuit) protected, protection device obtain Za, Zb, Zc, ZKa at its installation place survey calculation,
ZKb, ZKc, ZKab, ZKbc, ZKca.
As it is shown in figure 1, the phase selection method for double-circuit of the present invention, comprise the following steps:
One, cross-line phase selection put into judgement 1, protection device respectively by Za, Zb, Zc, ZKa, ZKb, ZKc, ZKab, ZKbc,
ZKca and ZkxspComparing, work as Za, the arbitrary phase in Zb, Zc, ZKa, ZKb, ZKc, ZKab, ZKbc, ZKca is selected less than cross-line
Phase definite value ZkxspTime, device enters cross-line phase selection and judges.If this condition is unsatisfactory for, i.e. Za, Zb, Zc, ZKa, ZKb, ZKc, ZKab,
ZKbc, ZKca are all higher than Zkxsp, then cross-line phase selection terminates.
Two, meeting three-phase low-impedance criterion and judge 2, three-phase low-impedance criterion is: ZMax<0.1Zkxsp, or ZMax<1.2ZMin。
Device judges to meet three-phase low-impedance criterion (YES), carries out meeting negative sequence voltage and judges 3.
If device judges to be unsatisfactory for three-phase low-impedance criterion (no), carry out meeting single-phase fault impedance criterion and judge 6.
Three, meeting negative sequence voltage criterion and judge 3, negative sequence voltage criterion is: 3U2> 9V, in negative sequence voltage criterion formula, U2For
Negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt.
Device judges to meet negative sequence voltage criterion (YES), detects cross-line phase to phase fault 4.
If device judges to be unsatisfactory for negative sequence voltage criterion (no), travel direction element criterion filters 5.
Negative sequence voltage is the calculated negative sequence voltage of protection device.
Four, detection cross-line phase to phase fault 4, illustrates as a example by AB is biphase, and cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
Device detects whether AB, BC, CA are biphase meets cross-line phase to phase fault criterion respectively, sentences if meeting cross-line phase to phase fault
According to 1) to 5) in any one, then be judged as phase-to phase fault, phase selection terminates.
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, travel direction element criterion filters 5.
U2、I1、I2、Uab1、IabBeing calculated by protection device, computing formula is as follows:
Iab=Ia-Ib。
Described directional element criterion filters 5, and directional element criterion is:UpolFor polarization
Voltage,For each phase current.
When three-phase all meets directional element criterion, for three-phase fault, phase selection terminates.
If an only phase or biphase meet directional element criterion in three-phase, then it it is each phase (meeting directional element criterion
Phase or biphase) fault, phase selection terminates.
If three-phase is all unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates.
Upol、Being calculated by protection device, computational methods are as follows:
Polarizing voltage UpolTake positive sequence voltage U1,
The each phase current collected for device, i.e. A phase current Ia, B phase current Ib, C phase current Ic。
In described step 2, device judges to be unsatisfactory for three-phase low-impedance criterion (no), carries out meeting single-phase fault impedance and sentences
It is judged that 6, single-phase fault impedance criterion is:
1), ZMin<0.5ZMax, or ZMin<0.1Zkxsp；
2), ZMin<0.5ZMid；
3), ZMid>0.1Zkxsp。
If device judges to meet the 1 of single-phase fault impedance criterion simultaneously) to 3) item condition time, then meet single-phase fault impedance
Criterion, detects phase to phase impedance minimum phase fault 7.
If device meets the 1 of single-phase fault impedance criterion when judging different) to 3) item condition time, then single-phase former for being unsatisfactory for
The anti-criterion of barrier, carries out meeting phase-to phase fault impedance criterion and judges 9.
Detection phase to phase impedance minimum phase fault 7, phase to phase impedance minimum refers to ZKab mutually, the minima institute in ZKbc, ZKca
Corresponding is separate.Use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault 4, the event mutually of detection phase to phase impedance minimum
Barrier, cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2 be negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
Device detects whether AB, BC, CA are biphase meets cross-line phase to phase fault criterion respectively, sentences if meeting cross-line phase to phase fault
According to 1) to 5) in any one, then be judged as phase-to phase fault, phase selection terminates.
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, detect single phase impedance minimum phase fault 8.
Described detection single phase impedance minimum phase fault 8, uses directional element criterion to filter 5, and directional element criterion is:UpolFor polarizing voltage,For each phase current.
When meeting directional element criterion, for single-phase fault, phase selection terminates.
If being unsatisfactory for directional element criterion, use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault 4, inspection
Survey single phase impedance big-and-middle phase phase-to phase fault.Cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
If meeting cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as single phase impedance big or middle mutually alternate therefore
Barrier, phase selection terminates.
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, the unselected phase that is out of order, phase selection terminates.
Single phase impedance minimum refers to Za mutually, separate corresponding to the minima in Zb, Zc；The big or middle phase of single phase impedance refers to
Separate corresponding to maximum in Za, Zb, Zc and intermediate value.
Described carrying out meeting single-phase fault impedance criterion and judge 6, sentencing if meeting single-phase fault impedance when device judges different
According to 1) to 3) and item condition time, then for being unsatisfactory for single-phase fault impedance criterion, carry out meeting phase-to phase fault impedance criterion and judge 9,
Phase-to phase fault impedance criterion is:
1), ZMin<0.1Zkxsp, or ZMin<0.5ZMax；
2), ZMid<0.1Zkxsp, or ZMid<0.5ZMax。
If device judges to meet the 1 of phase-to phase fault impedance criterion) and 2) item, detect the medium and small phase fault of phase to phase impedance 10.
If device judges to be unsatisfactory for the 1 of phase-to phase fault impedance criterion) and 2) item, carry out judging end fault impedance criterion
11。
The detection medium and small phase fault of phase to phase impedance 10, uses the cross-line phase to phase fault of step 4 detection cross-line phase to phase fault 4 to sentence
According to, detect the medium and small phase fault of phase to phase impedance.Cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
If device judges to meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as that phase to phase impedance is middle or small
Phase fault, phase selection terminates.
If device judges to be unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, use directional element criterion to filter phase to phase impedance
Middle or small phase, directional element criterion is:UpolFor polarizing voltage,For each phase current.
If device judges that the middle or small phase of phase to phase impedance all meets directional element criterion, then it is judged as the event of phase to phase impedance middle or small phase
Barrier, phase selection terminates.
If device judges only have phase in phase to phase impedance, meet directional element criterion, be then judged as phase fault in phase to phase impedance,
Or device judges that the only little phase of phase to phase impedance meets directional element criterion, being then judged as the little phase fault of phase to phase impedance, phase selection terminates.
If device judges all to be unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates.
The middle or small phase of phase to phase impedance refers to ZKab, separate corresponding to intermediate value in ZKbc, ZKca and minima.
Described carry out meeting phase-to phase fault impedance criterion and judge 9, if device judges to be unsatisfactory for phase-to phase fault impedance criterion
1) and 2) item, carry out judging that end fault impedance criterion 11, end fault impedance criterion are:
1), A phase of impedance maximum, and ZKbc < 1.5ZMin；
2), B phase of impedance maximum, and ZKca < 1.5ZMin；
3), C phase of impedance maximum, and ZKab < 1.5ZMin；
4), ZMid<Zkxsp。
If device judge meet the 1 of end fault impedance criterion), 2) or 3) item, add end fault impedance criterion 4) item,
Judge to meet end fault impedance criterion (YES), detect the medium and small phase fault of phase to phase impedance 10.
The detection medium and small phase fault of phase to phase impedance 10 uses the cross-line phase to phase fault of step 4 detection cross-line phase to phase fault 4 to sentence
According to, detect the medium and small phase fault of phase to phase impedance.Cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
If device judges to meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as that phase to phase impedance is middle or small
Phase fault, phase selection terminates.
If device judges to be unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, use directional element criterion to filter phase to phase impedance
Middle or small phase, directional element criterion is:UpolFor polarizing voltage,For each phase current.
If device judges that the middle or small phase of phase to phase impedance all meets directional element criterion, then it is judged as the event of phase to phase impedance middle or small phase
Barrier, phase selection terminates.
If device judges only have phase in phase to phase impedance, meet directional element criterion, be then judged as phase fault in phase to phase impedance,
Or device judges that the only little phase of phase to phase impedance meets directional element criterion, being then judged as the little phase fault of phase to phase impedance, phase selection terminates.
If device judges all to be unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates.
If device judge be unsatisfactory for the 1 of end fault impedance criterion), 2) or 3) item, add end fault impedance criterion 4)
, it is judged that it is unsatisfactory for end fault impedance criterion, detects single phase impedance minimum phase fault 8.
Detection single phase impedance minimum phase fault 8 uses directional element criterion to filter 5, and directional element criterion is:UpolFor polarizing voltage,For each phase current.
When meeting directional element criterion, for single-phase fault, phase selection terminates.
If being unsatisfactory for directional element criterion, use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault 4, inspection
Survey single phase impedance big-and-middle phase phase-to phase fault.Cross-line phase to phase fault criterion is:
1), 3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2), 3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1Be 3 times just
Sequence electric current；
3),Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5),IaFor A phase current, IbFor B phase current.
If meeting cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as single phase impedance big or middle mutually alternate therefore
Barrier, phase selection terminates.
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, the unselected phase that is out of order, phase selection terminates.
The method of the present invention utilizes the various impedances calculated to judge, draws phase selection result, when there is cross line fault
Can the accuracy of significant increase phase selection, and prior art uses difference fluid element to carry out phase selection, in vertical and distance protection, difference stream
Element phase selection can not be used, and can not apply when passage is problematic, and therefore the phase-selecting method of prior art is choosing cross-line near-end
During fault can also accurate phase selection, but the most helpless to far-end fault, the method for the present invention has only to protection device collection transmission of electricity
The information of this side of circuit, it is not necessary to the transmission line of electricity offside information of channel transfer, so not by pass effect, so being applicable to indulge
UNPROFOR is protected and distance protection, and the method for the present invention easily realizes in microcomputer protective relay, it is ensured that the reliability of action and spirit
Quick property.
Embodiment: the microprocessor DSP that protection device uses TI company of Texas Instrument model to be TMS320C33, uses TI
The Composer V4.10 compilation tool of company.Line protection for Guangdong Power Grid 220kV electric pressure.
Judge the instruction whether cross-line phase selection puts into:
Judge to meet the instruction of three-phase low-impedance criterion:
Judge to meet the instruction of negative sequence voltage criterion:
if(fAmp3U2>CN_SELPHS_U9V)
{
The instruction of detection cross-line phase to phase fault:
Through the instruction that directional element criterion filters:
Judge to meet the instruction of single-phase fault impedance criterion:
The instruction of detection phase to phase impedance minimum phase fault:
The instruction of detection single phase impedance minimum phase fault:
Judge to meet the instruction of phase-to phase fault impedance criterion:
The instruction of the detection medium and small phase fault of phase to phase impedance:
Judge the instruction of end fault impedance criterion:
The instruction that phase selection terminates:
The present embodiment is relative to the phase-selecting method of prior art, and when there is cross line fault, energy significant increase phase selection is accurate
Degree, with difference fluid element phase selection compared with, the method for the present invention is not affected by passage, and reliability is higher, it is adaptable to pilot protection and
Distance protection.
Claims (1)
1. a phase selection method for double-circuit, comprises the following steps:
One, cross-line phase selection puts into and judges (1), and protection device will be gone zero sequence A phase to measure impedance Z a respectively, and be gone zero sequence B phase to measure resistance
Anti-Zb, goes zero sequence C phase to measure impedance Z c, and the phase containing zero sequence A measures impedance Z Ka, and the phase containing zero sequence B measures impedance Z Kb, containing zero sequence C phase
Measuring impedance Z Kc, the phase containing zero sequence AB measures impedance Z Kab, and the phase containing zero sequence BC measures impedance Z Kbc, and the phase containing zero sequence CA measures impedance
ZKca and ZkxspCompare, ZkxspFor cross-line phase selection definite value, fix and take the 60% of total track length positive sequence impedance；Work as Za, Zb, Zc,
Arbitrary phase in ZKa, ZKb, ZKc, ZKab, ZKbc, ZKca is less than cross-line phase selection definite value ZkxspTime, device enters cross-line phase selection and sentences
Disconnected；If this condition described is unsatisfactory for, i.e. Za, Zb, Zc, ZKa, ZKb, ZKc, ZKab, ZKbc, ZKca are all higher than Zkxsp, then cross-line
Phase selection terminates；
Two, meeting three-phase low-impedance criterion and judge (2), three-phase low-impedance criterion is: ZMax<0.1Zkxsp, or ZMax<1.2ZMin, its
Middle ZMaxFor Za, the maximum in Zb, Zc, ZMinFor Za, the minima in Zb, Zc；
Device judges to meet three-phase low-impedance criterion, carries out meeting negative sequence voltage and judges (3)；
If device judges to be unsatisfactory for three-phase low-impedance criterion, carry out meeting single-phase fault impedance criterion and judge (6)；
Three, meeting negative sequence voltage criterion and judge (3), negative sequence voltage criterion is: 3U2> 9V, in negative sequence voltage criterion formula, U2It is negative
Sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
Device judges to meet negative sequence voltage criterion, detection cross-line phase to phase fault (4)；
If device judges to be unsatisfactory for negative sequence voltage criterion, travel direction element criterion filters (5)；
Negative sequence voltage is the calculated negative sequence voltage of protection device；
Four, detection cross-line phase to phase fault (4), cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For the biphase positive sequence voltage of AB, IabFor biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
Device detects whether AB, BC, CA are biphase meets cross-line phase to phase fault criterion, if meeting cross-line phase to phase fault criterion 1 respectively)
To 5) in any one, then be judged as phase-to phase fault, phase selection terminates；
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, travel direction element criterion filters (5)；
U2、I1、I2、Uab1、IabBeing calculated by protection device, computing formula is as follows:
Iab=Ia-Ib；
Described directional element criterion filters (5), and directional element criterion is:UpolFor polarization electricity
Pressure,For each phase current；
When three-phase all meets directional element criterion, for three-phase fault, phase selection terminates；
If an only phase or biphase meet directional element criterion in three-phase, then it is each phase fault meeting directional element criterion, choosing
Terminate mutually；
If three-phase is all unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates；
Upol、Being calculated by protection device, computational methods are as follows:
Polarizing voltage UpolTake positive sequence voltage U1,
The each phase current collected for device, i.e. A phase current Ia, B phase current Ib, C phase current Ic；
In described step 2, device judges to be unsatisfactory for three-phase low-impedance criterion, carries out meeting single-phase fault impedance criterion and judges
(6), single-phase fault impedance criterion is:
1)、ZMin<0.5ZMax, or ZMin<0.1Zkxsp；
2)、ZMin<0.5ZMid；
3)、ZMid>0.1Zkxsp；
ZMidFor Za, the intermediate value in Zb, Zc；
If device judges to meet the 1 of single-phase fault impedance criterion simultaneously) to 3) item condition time, then meet single-phase fault impedance and sentence
According to, detection phase to phase impedance minimum phase fault (7)；
If device meets the 1 of single-phase fault impedance criterion when judging different) to 3) item condition time, then hinder for being unsatisfactory for single-phase fault
Anti-criterion, carries out meeting phase-to phase fault impedance criterion and judges (9)；
Detection phase to phase impedance minimum phase fault (7), phase to phase impedance minimum refers to ZKab mutually, and the minima institute in ZKbc, ZKca is right
That answers is separate；Use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault (4), the event mutually of detection phase to phase impedance minimum
Barrier, cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
Device detects whether AB, BC, CA are biphase meets cross-line phase to phase fault criterion, if meeting cross-line phase to phase fault criterion 1 respectively)
To 5) in any one, then be judged as phase-to phase fault, phase selection terminates；
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, detection single phase impedance minimum phase fault (8)；
Described detection single phase impedance minimum phase fault (8), uses directional element criterion to filter (5), and directional element criterion is:UpolFor polarizing voltage,For each phase current；
When meeting directional element criterion, for single-phase fault, phase selection terminates；
If being unsatisfactory for directional element criterion, use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault (4), detection
Single phase impedance big-and-middle phase phase-to phase fault；Cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
If meeting cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as single phase impedance big or middle phase phase-to phase fault, choosing
Terminate mutually；
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, the unselected phase that is out of order, phase selection terminates；
Single phase impedance minimum refers to Za mutually, separate corresponding to the minima in Zb, Zc；The big or middle phase of single phase impedance refers to Za,
Separate corresponding to maximum in Zb, Zc and intermediate value；
Described carrying out meets single-phase fault impedance criterion judgement (6), if meeting single-phase fault impedance criterion when device judges different
1) to 3) and item condition time, then for being unsatisfactory for single-phase fault impedance criterion, carry out meeting phase-to phase fault impedance criterion and judge (9),
Phase-to phase fault impedance criterion is:
1)、ZMin<0.1Zkxsp, or ZMin<0.5ZMax；
2)、ZMid<0.1Zkxsp, or ZMid<0.5ZMax；
If device judges to meet the 1 of phase-to phase fault impedance criterion) and 2) item, the detection medium and small phase fault of phase to phase impedance (10)；
If device judges to be unsatisfactory for the 1 of phase-to phase fault impedance criterion) and 2) item, carry out judging end fault impedance criterion
(11)；
The detection medium and small phase fault of phase to phase impedance (10), uses the cross-line phase to phase fault of step 4 detection cross-line phase to phase fault (4) to sentence
According to, detecting the medium and small phase fault of phase to phase impedance, cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For biphase positive sequence voltage, IabFor biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
If device judges to meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as the middle or small phase of phase to phase impedance therefore
Barrier, phase selection terminates；
If device judges to be unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, use directional element criterion to filter in phase to phase impedance,
Little phase, directional element criterion is:UpolFor polarizing voltage,For each phase current；
If device judges that the middle or small phase of phase to phase impedance all meets directional element criterion, then it is judged as the middle or small phase fault of phase to phase impedance,
Phase selection terminates；
If device judges only have phase in phase to phase impedance, meet directional element criterion, be then judged as phase fault in phase to phase impedance, or dress
Putting the judgement only little phase of phase to phase impedance and meet directional element criterion, be then judged as the little phase fault of phase to phase impedance, phase selection terminates；
If device judges all to be unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates；
The middle or small phase of phase to phase impedance refers to ZKab, separate corresponding to intermediate value in ZKbc, ZKca and minima；
Described carrying out meets phase-to phase fault impedance criterion judgement (9), if device judges to be unsatisfactory for phase-to phase fault impedance criterion
1) and 2) item, carries out judging that end fault impedance criterion (11), end fault impedance criterion are:
1), A phase of impedance maximum, and ZKbc < 1.5ZMin；
2), B phase of impedance maximum, and ZKca < 1.5ZMin；
3), C phase of impedance maximum, and ZKab < 1.5ZMin；
4)、ZMid<Zkxsp；
If device judge meet the 1 of end fault impedance criterion), 2) or 3) item, meet end fault impedance criterion 4 simultaneously) item,
Judge to meet end fault impedance criterion, the detection medium and small phase fault of phase to phase impedance (10)；
The detection medium and small phase fault of phase to phase impedance (10) uses the cross-line phase to phase fault of step 4 detection cross-line phase to phase fault (4) to sentence
According to, detecting the medium and small phase fault of phase to phase impedance, cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For the biphase positive sequence voltage of AB, IabFor AB biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
If device judges to meet cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as the middle or small phase of phase to phase impedance therefore
Barrier, phase selection terminates；
If device judges to be unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, use directional element criterion to filter in phase to phase impedance,
Little phase, directional element criterion is:UpolFor polarizing voltage,For each phase current；
If device judges that the middle or small phase of phase to phase impedance all meets directional element criterion, then it is judged as the middle or small phase fault of phase to phase impedance,
Phase selection terminates；
If device judges only have phase in phase to phase impedance, meet directional element criterion, be then judged as phase fault in phase to phase impedance, or dress
Putting the judgement only little phase of phase to phase impedance and meet directional element criterion, be then judged as the little phase fault of phase to phase impedance, phase selection terminates；
If device judges all to be unsatisfactory for directional element criterion, being then reverse direction failure, phase selection terminates；
If device judge be unsatisfactory for the 1 of end fault impedance criterion), 2) or 3) item, be unsatisfactory for end fault impedance criterion simultaneously
4) item, it is judged that be unsatisfactory for end fault impedance criterion, detection single phase impedance minimum phase fault (8)；
Detection single phase impedance minimum phase fault (8) uses directional element criterion to filter (5), and directional element criterion is:UpolFor polarizing voltage,For each phase current；
When meeting directional element criterion, for single-phase fault, phase selection terminates；
If being unsatisfactory for directional element criterion, use the cross-line phase to phase fault criterion of step 4 detection cross-line phase to phase fault (4), detection
Single phase impedance big-and-middle phase phase-to phase fault；Cross-line phase to phase fault criterion is:
1)、3U2> 9V, U2For negative sequence voltage, 3U2Being 3 times of negative sequence voltages, V is voltage unit volt；
2)、3I2>0.125×3I1, I2For negative-sequence current, 3I2It is 3 times of negative-sequence currents, I1For forward-order current, 3I1It is 3 times of positive sequence electricity
Stream；
3)、Uab1For biphase positive sequence voltage, IabFor biphase current；
4), ZKab < 1.5Za, and ZKab < 1.5Zb；
5)、IaFor A phase current, IbFor B phase current；
If meeting cross-line phase to phase fault criterion 1) to 5) in any one, then be judged as single phase impedance big or middle phase phase-to phase fault, choosing
Terminate mutually；
If being unsatisfactory for cross-line phase to phase fault criterion 1) to 5) item, the unselected phase that is out of order, phase selection terminates.
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| CN104237741A (en) * | 2014-09-28 | 2014-12-24 | 中国南方电网有限责任公司 | Intelligent station domain information based double-circuit line fault phase selection method |
| CN105699842A (en) * | 2015-12-15 | 2016-06-22 | 南京南瑞集团公司 | Direct current near zone alternating current line phase-to-phase fault criterion used by stable control device |
| CN107024637A (en) * | 2016-01-29 | 2017-08-08 | 中国电力科学研究院 | A kind of double-circuit line on same pole phase-selecting method based on single loop line information |
| CN107516880B (en) * | 2017-09-06 | 2021-12-21 | 中国电力科学研究院 | Pseudo-synchronous differential impedance protection phase selection method and device for half-wavelength power transmission line |
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| US8081002B2 (en) * | 2008-04-29 | 2011-12-20 | Abb Technology Ag | Apparatus and method for determining location of phase-to-phase fault or three-phase fault |
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