CN100424953C - Re-switch on method for electric tansmission device - Google Patents

Abstract

The present invention relates to a reclosing method for transmission lines. A double-circuit parallel transmission line can be protected by the present invention by a relay; each single circuit line of the double-circuit parallel transmission line needs to be singly configured and protected, and the main protection of the double-circuit parallel transmission line adopts phase splitting current differential protection or pilot protection with phase splitting commands; for various single circuit line faults and overline faults in a zone, fault phases need to be selectively tripped to realize self-adaptive reclosing operation. The present invention is a self-adaptive reclosing method which is used for high voltage transmission lines and ultra-high voltage transmission lines when transmission lines have faults; the line protection combines a criterion without serious permanent faults on the basis of accurately and selectively tripping fault phases to carry out coincidence according to phase sequence, namely that phases are tripped in a phase splitting and coinciding mode in sequence. After the double-circuit parallel transmission line has a fault, the double-circuit parallel transmission line is permitted to coincide when at least two different phases in the double-circuit parallel transmission line are complete; otherwise, two circuit lines need to be fully tripped. On the basis of impact of permanent faults caused by minimized coincidence on the system, the coincident opportunity and the coincident successful rate of the system are improved to the maximum.

Description

A kind of reclosing method of transmission line

Technical field

The present invention relates to a kind of reclosing method of transmission line, especially double-circuit lines on the same pole relay protecting method and utilize the method for novel reclosing protection.

Background technology

Require to give full play to the ability of circuit transferring electric power along with electricity market development, power grid construction; The double-circuit lines on the same pole road is compared with two single back lines, and project cost is low, the electric outgoing line corridor width is little, the construction period short, and economic benefit is obvious.Therefore, under the situation of land expropriation cost height, electric outgoing line corridor anxiety, usually adopt the double-circuit lines on the same pole road.

External extra high voltage network has the operating experience of success in this respect, as the electrical network of Japan, European all states, and its high pressure, most of two (even the many times) circuits that return of parallel lines on same tower that adopt of supertension line, the economic benefit of being brought is fairly obvious.In China, send the construction of project of transmitting and converting electricity and the development that national superhigh pressure is striden the Da Qu interconnected network along with Three Gorges are supporting, transmission of electricity is becoming tight corridor day, the 500KV double-circuit lines on the same pole will be on the increase, will show its potential huge technical economic benefit especially, meanwhile, also bring some special technique problems to operation of power networks.

From the angle of relaying protection specialty, double-circuit lines on the same pole is compared with common single loop line, and the main feature of its fault is that cross line fault is arranged.The simple fault of single loop line has 11 kinds, and the fault of double-circuit lines on the same pole then reaches 120 kinds.In 120 kinds of double-circuit lines on the same pole faults, 63 kinds of earth faults, 57 kinds of earth-free faults; 22 kinds of single line downs, 98 kinds of cross line faults.The original statistics of China shows cross line fault seldom, only accounts for 2%～3% of double-circuit lines on the same pole total failare.And external statistics are much bigger, and according to Tokyo Electric Power statistics, in the period of 1973 to 1999 27, the double-circuit lines on the same pole generation cross-line of 500KV electric pressure 25 times accounts for during the statistics all 8.9% of faults; And equally in Japan, according to the statistics of company of Chubu Electric Power to 275KV and above electrical network over nearly 5 years, cross line fault accounts for the ratio of whole faults then up to 20%.Along with the increase of China's parallel lines on same tower transmission line, the probability of cross line fault also is certain to increase.Between age at failure, how to keep the electrical link of system to greatest extent, reduce the possibility lose double loop simultaneously, keep the stable operation of electrical network, our starting point of carrying out the work also is the key point of problem just.Therefore, the special technique problem of double-circuit lines on the same pole relaying protection and reclosing is studied, determined the relaying protection of double-circuit lines on the same pole and the specification requirement of reclosing, existing important theory is worth, and also is to produce actual pressing for.

The parallel lines on same tower double back transmission line is to the specific (special) requirements of relaying protection

1. select the phase problem

The phase-selecting method that only reacts circuit one side electric parameters can't be distinguished single line down, cross line fault and the double loop external fault of double-circuit lines on the same pole road end.Domestic popular current break selects facies principle at present, has lost on double-circuit lines on the same pole and has correctly selected the phase ability, is not suitable for double-circuit lines on the same pole.Impedance and other phase-selecting methods, though major part can correctly be selected phase, but when double-circuit lines on the same pole different name phase cross line fault takes place near circuit two terminals, to judge by accident away from the phase selection element of fault side and to be phase-to phase fault, thereby all being judged by accident, the double loop is heterogeneous fault, cause double loop all to trip, the stable operation of serious threat system safety.

2. zero-sequence mutual inductance problem

The zero-sequence mutual inductance coefficient of double-circuit lines on the same pole is bigger, and the bus residual voltage not only is decided by this line current when making earth fault, but also is subjected to the influence of adjacent line zero-sequence current, influences the actuating range of both sides ground distance protection; Under the situation of faulty line near the tripping operation earlier of fault point switch, because the influence of zero-sequence mutual inductance, the zero-sequence current protection scope of faulty line adjacent line also will change, and may cause protection malfunction or tripping simultaneously.

3. reclosing problem

Even phase can be correctly selected at present existing reclosing device protection, but can not keep the electrical link of system to greatest extent when the three-phase cross line fault, thereby influences the stable operation of system.As: L1 line A phase earth fault takes place, L2 line BC phase fault, the L1 line carries out single-pole reclosing, and the L2 line is jumped three-phase and is not overlapped, and reduces to the contact of 2 lines by 6 lines between two stations during the reclosing; When generation L1 line AB phase earth fault, L2 line BC phase fault, the equal three-phase tripping operation of L1, L2 does not overlap.Bigger to the system stability influence.

In addition, modern high-rating generator does not allow when heterogeneous fault takes place automatic reclosing immediately, damages generator when preventing to coincide with permanent fault.In when, on double-circuit lines on the same pole two-phase two lead cross-line permanent faults taking place, to every loop line is single-phase fault, and concerning generator, stood the once impact of heterogeneous fault, therefore the reclosing of two loop lines should be taken measures, and avoids generator to stand the impact of heterogeneous fault.

Domestic and international research situation

The comparison morning that the protection problem of double-circuit lines on the same pole proposes, the relaying protection expert had certain theoretical research to relevant problem both at home and abroad for a long time, had obtained some interim achievements.The Japan 500KV circuit overwhelming majority is a double-circuit lines on the same pole, and abundant operating experience is arranged.Along with double-circuit lines on the same pole increase and to the progressively attention of relevant issues, more domestic net province offices, research institutions are also being studied, and have obtained the practical experience and the theoretical research result of some operations.

(1), double-circuit lines on the same pole relaying protection implementation

Mainly contain following several protection scheme at present both at home and abroad:

1, rely on vertical continuous action to realize that cross line fault correctly selects phase.After waiting for the offside circuit breaker trip under the heterogeneous fault, reach the correct choosing of this side purpose that trips mutually.The carrier current protection action; when phase selection element is judged to heterogeneous fault, might be double-circuit lines on the same pole cross-line different name phase fault, falsely drop tripping operation mutually for preventing fault point far away side; be provided with the delay tripping loop, this time-delay should protect correct choosing to reach the trip time mutually greater than another loop line of offside (near fault point).Could solve the double-circuit lines on the same pole cross line fault like this and falsely drop the phase problem.This scheme has following shortcoming:

A. if the protection on the loop line or during the circuit breaker tripping, this circuit fault end far away will be thought heterogeneous fault, after certain time-delay with this line three-phase tripping operation.Three-phase is also jumped because of the protection of the nearly fault end of adjacent line or circuit breaker tripping misss in another loop line road, so causes double loop all to have a power failure.

B. when heterogeneous fault took place this circuit, delay tripping all is with in the both sides protection, and was unfavorable to system stability.

C. double-circuit lines on the same pole generation different name phase cross line fault, fault point far away side protection delay tripping.Unfavorable to system stable operation.

2, the vhf range protection of split phase signal transmission

During double-circuit lines on the same pole different name phase cross line fault, the impedance phase selection element of nearly fault point side can correctly select phase.Adopt the vhf range protection of split phase signal transmission, the phase result is selected in the protection exchange of circuit both sides after fault, and then correctly selects the fault phase, realizes the correct fast phase trip avoidance function that selects.Protection need not be provided with the stand-by period of heterogeneous fault, can excise heterogeneous fault both sides switch fast, plays key effect to improving power system safety and stability.But this scheme has higher requirements to passage, must have multichannel could realize transmitting phase-splitting and select phase signals.Adopt many command signals of multichannel FSK system to meet the demands, but when circuit processing phase short circuit or line outlet place three-phase shortcircuit occurring, carrier current protection is with tripping or deferred action.Present domestic Multiplexing Carrier passage uses at most, and optical-fibre channel progressively increases, and microwave channel uses seldom.The U.S., Japan are based on optical fiber and digital microwave passage.Main protection of this type and number of channels thereof require as shown in table 1 below:

Table 1

Model	Manufactory	Number of channels
			LFP-902C	Nan Rui company	The triple channel or the four-way of duplex
RCS-902C	Nan Rui company	The triple channel or the four-way of duplex
			REL531	ABB	The triple channel or the four-way of duplex
ALPS	GE	Two passages or the four-way of duplex

But this scheme is many excision one phases when line end three-phase three wires cross line fault, and three-phase four lead cross line faults and have two soundly will excise two loop lines when belonging to two loop lines mutually are unfavorable to system stable operation endways.

3, differential current protection

The differential current protection philosophy is simple and reliable, and conventional fault and cross line fault are had the natural phase ability of selecting, all can correct, choosing tripping operation mutually fast to double-circuit lines on the same pole cross-line different name phase fault.Japan's supertension line main protection all is the differential current protection of adopting.But it is very high that it requires passage, requires to have 6 independently signalling channels, passage investment cost height.Protect simultaneously the passage error rate, transmission delay etc. are all had higher requirements.Domestic main use special optic fibre passage, OPGW is used more; The U.S., Japanese multiple connection communication link (PCM) mode based on 64kbit/s.

(2), reclosing mode

The reclosing function that adapts with the double-circuit lines on the same pole relaying protection also is that power network safety operation is necessary.Some manufacturing firms have carried out further research and application on the basis of conventional single-phase/three-phase/composite auto-reclosing.As: 2.0 versions of the REL500 series that ABB AB produces, its reclosing mode is single-phase/two-phase/three-phase reclosing.Promptly carry out single-pole reclosing when single-phase fault, when two phase ground or phase to phase fault, tripping two fault phases are carried out the two-phase reclosing again.When three-phase fault, can according to condition carry out three-phase or reclosing not.Can realize multiple shot reclosing in addition.L1 line A phase fault takes place in working as of mentioning in front, when L2 line B, C phase fault, after adopting the reclosing of REL500 series, L1 line tripping A phase, L2 line tripping B, C phase, kept having 3 lead contacts of the complete three-phase of ABC this moment between two stations, improved the stability of electric power system, but when overlapping, may make system be subjected to the impact once more of phase-to phase fault.

Abroad, the breaker tripping and closing mode of double-circuit line on same pole protective relaying device is also inequality.

1, at Electricite De France (EDF), the two cover split-phase longitudinal difference protections that the general configuration principle of its double-circuit line on same pole relaying protection is identical, when single-phase fault takes place when, single-phase tripping operation, single-phase again coincidence is if unsuccessful reclosing is just jumped three-phase; Phase-to phase fault is directly jumped three-phase, does not overlap.Do not protect the exchange of information between two loop lines with bar.This side is not collected the position of the switch information of this circuit and adjacent lines offside yet.Basic identical with the breaker tripping and closing mode that present China adopts.

2, adopting the maximum country Japan of double-circuit line on same pole, the two cover split-phase type longitudinal difference protections that the general configuration principle of its double-circuit line on same pole relaying protection is identical are with the protection information and the position of the switch information of optical fiber or microwave transmission both sides.With the exchange that will protect information between the adjacent double loop of bar.After breaking down, double-circuit line on same pole only jumps the fault phase.For the multiphase reclosing mode, each Utilities Electric Co. considers different.As company of Tokyo Electric Power, the structure of the occupation mode of reclosing and electric pressure and power transmission line is closely related.For the backbone network of 275kV, 500kV,,, generally adopt multiphase reclosing for fear of the serious accident that loses two loop lines simultaneously because power transmission line all is a double-circuit lines on the same pole; For the 154kV circuit, on double-circuit lines on the same pole, adopt multiphase reclosing, single back line adopts single-pole reclosing, and also some places directly adopt the three-phase reclosing; For the then unified three-phase reclosing that adopts of 66kV, 22kV, 6.6kV.Its concrete mode and reclosure time are as shown in table 2.

Table 2, Tokyo (Tokyo) Utilities Electric Co.'s various electric pressure circuit reclosing mode and circuit breaker contrast table operate time

Japan Chubu Electric Power company: to various fault types, only carry out fault is carried out sequential trip mutually, tripping and reclosing when differentiating, based on following consideration:

A, for 275KV and above double-circuit line on same pole road, no matter the fault of which kind of type takes place, equal tripping fault phase after the protection action.At this moment, if a loop line generation three-phase fault, another loop line is intact, then after passing through PCM communication acknowledgement offside and adjacent lines information, adopts middling speed reclosing mode (about 10 seconds) to overlap.At first, system side overlaps, and behind the system side successful reclosing, mains side is collected this line offside and adjacent line and offside information by PCM communication, overlaps after about 3 seconds.

B, the such fault of IBIIC that takes place for double-circuit line on same pole; after the protection action; only jump fault phase IBIIC, then the II line is carried out single-pole reclosing (be 0.35-0.835 second reclosing time) at a high speed, the I line is then adopted middling speed reclosing (be about 10 seconds reclosing time).To avoid two loop lines to coincide with the impact that permanent fault is brought to generator simultaneously.Owing at this moment have only a loop line to adopt high-speed reclosing, so the circuit both sides are to overlap simultaneously.

C, for the such fault of IBCIIC that double-circuit line on same pole takes place, after the protection action, only jump fault phase IBCIIC, after the tripping operation, also surplus IAIIAB operation.Because this moment, the II line also had A, B two-phase, at first the II line was carried out single-pole reclosing at a high speed.Be 0.35-0.835 second reclosing time.If the IIC successful reclosing, the I line after detecting the II line and recovering fully, tripping I line perfect phase A phase, and then the I line is carried out middling speed reclosing (time was about about 10 seconds).

Reclosing mode and reclosure time that Japan Chubu Electric Power company allows to adopt when various fault is taken place for 500KV and 275KV electrical network see Table 3

Each electric pressure reclosure time table of table 3

Annotate: H-REC (S) expression high speed phase-splitting reclosing; H-REC represents high speed three-phase reclosing;

M-REC represents middling speed three-phase reclosing; L-REC represents low speed three-phase reclosing.

At present, Protection Technology has had significant progress, and the computer line protection of superior performance also obtains general application.If can only excise fault wire, realize multiphase reclosing during double-circuit lines on the same pole generation cross line fault, be undoubtedly useful keeping system stability.Keeping to improve the through-put power of power transmission line under the identical systems maintenance level, the performance economic benefit in other words.Though the probability of cross line fault is little, can not get rid of it may.As single loop line generation three-phase fault and be that three-phase also is minimum in the possibility of synchronization short circuit, but took place, so in this case, protection also should selectively be moved fast.Therefore, develop perfect having and select the computer line protection that is applicable to double-circuit lines on the same pole and the reclosing of phase ability to have general important meaning, also can realize fully.

Summary of the invention

The present invention seeks to: a kind of guard method of novel transmission of electricity circuit is provided, and especially the relay protecting method on double-circuit lines on the same pole road improves the double-circuit lines on the same pole coincidence factor, reduces the possibility of excising two loop lines simultaneously when cross line fault takes place; Alleviate and coincide with of the impact of permanent fault situation system; The relaying protection and the reclosing device that are adapted to double-circuit lines on the same pole for development and application provide technical basis.And the relaying protection of double-circuit line on same pole should be satisfied following requirement:

A) when cross line fault took place, protection is the fault phase of this circuit of tripping only, promptly relaying protection had been proposed the strict demand of correct selection fault phase and fault wire.

B) have only under the mode of loop line operation at double-circuit line on same pole, the relaying protection of double-circuit line on same pole should be able to correctly be worked.

C) after double-circuit line on same pole broke down the protection tripping operation, under the open-phase operation mode, relaying protection should be able to correctly be worked.

The present invention seeks to realize like this: a kind of reclosing method of transmission line, to the relaying protection of double-circuit lines on the same pole road: every loop line road of double-circuit lines on the same pole is configuration protection separately, the main protection on double-circuit lines on the same pole road is adopted the differential current protection or is had the pilot protection of branch phase command, for various forms of single line downs and cross line fault in the district, all should select the jumping fault to come mutually, realize adaptive reclose: a kind of adaptive reclose that when transmission line breaks down, is applied to high pressure and extra high voltage network, route protection carries out reclosing according to phase order accurately selecting on the basis of jumping the fault phase in conjunction with no serious permanent fault criterion; Promptly in order, successively divide the tripping phase that coincides; After double-circuit lines on the same pole breaks down, just allow when having at least two different names to perfect mutually in the double loop to overlap, otherwise, all trippings of two loop lines; Jump fault mutually to protect accurate choosing; During this transmission line single-phase fault, when phase to phase fault and three-phase fault, all only the fault phase is jumped in choosing, rather than phase to phase fault three is jumped; The operation information of comprehensive two loop lines of protective device overlaps by following rule ordering: coincidence by dividing phase sequence to overlap, overlaps and overlaps simultaneously with the famous prime minister is preferential in proper order; The leading phase of phase to phase fault circuit preferentially overlaps; Leading phase preferentially overlaps: determined whether to take place permanent earth fault nearby: U by tripping phase voltage criterion _φ＞Uzd U _φBe the tripping phase voltage, Uzd is a setting value, satisfies this voltage criterion and thinks there is not generation permanent earth fault nearby.Coincide with on the basis that permanent fault impacts to system minimizing, the chance that raising system to greatest extent overlaps and the probability of successful reclosing improve the transmission line ability that restores electricity after fault.The mode of dividing phase sequence to overlap solved and may coincide with heterogeneous permanent fault problem, solved the problem that the terminal voltage criterion can not be differentiated alternate permanent fault and three symmetrical permanent faults simultaneously.

For alternate earth-free permanent fault, overlap based on minute phase sequence, determine whether to have taken place permanent earth-free fault by following voltage criterion:

$|{\stackrel{\&CenterDot;}{U}}_P+{\stackrel{\&CenterDot;}{U}}_Y|>{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C20041006496000222.png,C20041006496000232.png"\; state="\{\{state\}\}">k</figure-callout>}}_1*|{\stackrel{\&CenterDot;}{U}}_P-{\stackrel{\&CenterDot;}{U}}_Y|$

k ₁Desirable 4-6;

Behind arbitrary combined floodgate mutually, if system satisfies the following formula condition, then be judged to alternate earth-free permanent fault, no longer continue to send out the order of phase-splitting reclosing.

If circuit replaces fully; the capacitor coupling voltage and the mutual voltage of sound symmetry three relative tripping phases will be very little, can not satisfy voltage criterion, and both sides are all thought serious permanent fault has taken place and do not overlapped; for remedying the deficiency that adopts the terminal voltage criterion, utilize the route protection internal information.As satisfy following arbitrary condition and think there is not generation catastrophe failure nearby, can overlap:

A) phase voltage during fault, voltage between phases are bigger;

B) do not rely on the not action of protection fast such as impedance I section, power frequency variation impedance of passage;

C) the range finding result is bigger.

When the reclosure time that do not automatically prolong during blow-out as yet of fault point under the transient fault situation, until the fault point blow-out, to improve the successful reclosing probability.For no shunt reactor circuit, during overlapping, self adaptation introduces based on the fault point blow-out criterion of voltage magnitude in conjunction with the voltage higher harmonic content.The blow-out criterion is:

$\left\{\begin{array}{c}{U}_{\mathrm{<figure-callout\; id="1"\; label="fd"\; filenames="C20041006496000222.png,C20041006496000232.png"\; state="\{\{state\}\}">fd</figure-callout>}1}\&GreaterEqual;{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20041006496000221.png"\; state="\{\{state\}\}">k</figure-callout>}}_2*U_N\\ (U_{\mathrm{fd}3}+U_{\mathrm{fd}5})<k_3*{\mathrm{<figure-callout\; id="1"\; label="U\; fd"\; filenames="C20041006496000222.png,C20041006496000232.png"\; state="\{\{state\}\}">U</figure-callout>}}_{\mathrm{fd}}\end{array}\right.$

k ₂Desirable 0.1-0.2 is as 0.1; k ₃Desirable 0.2-0.4 is as 0.2;

U _Fd1, U _Fd3, U _Fd5Be respectively the amplitude of first-harmonic, three times and the quintuple harmonics of tripping phase voltage.

For having the shunt reactor circuit, free oscillation voltage has appearred after the blow-out of fault point, and therefore disconnect the phase voltage amplitude and have than great fluctuation process, the blow-out criterion is: U _{Fd1_ave}〉=k ₄* U _Nk ₄Desirable 0.2-0.4 is as 0.2; U _{Fd1_ave}Mean value for fundamental voltage; U _P, U _YBe respectively the three-phase voltage vector, U _NIt is neutral point voltage.

Reclosing of the present invention should be pressed line configuring; the relative independentability and the integrality that keep double loop protection and reclosing; automatically transfer conventional reclosing when service conditions does not satisfy to when self adaptation overlaps, it is phase to phase fault three jumpings that the tripping operation mode of protection this moment should change to usual manner automatically.

Reclosing according to phase order lock of the present invention needs the operation information of comprehensive two loop lines, whether satisfies the sound mutually condition of two different names to differentiate; The operation conditions that contains this line in the route protection for obtaining the information of another loop line, is carried out information interaction by the optical fiber connection between the protection of homonymy double loop.The protection passage adopts digital channel transmission protection information such as optical fiber, microwave.

Blow-out criterion of the present invention, no serious permanent fault criterion are equally applicable to single back line.

Every loop line road of double-circuit lines on the same pole of the present invention is configuration protection separately, allows exchange message between two loop lines, and the information exchange between two loop lines in any case is unusual, does not allow to influence the basic function of each self-shield; The main protection on double-circuit lines on the same pole road is adopted the phase-splitting current protection or is had the pilot protection of branch phase command, and the protection passage adopts optical fiber or microwave channel, or the carrier channel of a plurality of quick orders transmission protection information;

During fixed value adjusting, to the super range distance element on double-circuit line on same pole road, terminal short circuit had enough sensitivity when double loop moved simultaneously; To owing the range distance element, when bonding loop line operation adjacent lines was hung the ground maintenance, terminal short circuit did not surmount.

Reclosing should be able to adapt to multiple different coincidence system according to the requirement of primary system, i.e. single-pole reclosing, three-phase reclosing, composite auto-reclosing, reclosing according to phase order lock;

The characteristics of double-circuit line on same pole protection

The main feature of double circuit lines is that cross line fault is arranged.The simple fault of single loop line has 11 kinds, and double circuit lines then reaches 120 kinds.In 120 kinds of double circuit lines, 63 kinds of earth faults, 57 kinds of earth-free faults; 22 kinds of single line downs, 98 kinds of cross line faults.Usually again cross line fault is divided into non-with the famous prime minister with famous prime minister's cross line fault.

Though cross line fault occupies landslide in failure modes; but the ratio of single line down is still more than 80%; the China's Statistical data shows that cross line fault seldom; only account for 2%～3% of double-circuit line on same pole total failare; data much smaller than foreign statistic; protection problem when this considers fault with regard to requiring us comprehensively, the protection problem in the time of promptly not only will considering cross line fault, the protection problem in the time of also will considering single line down.

Another characteristics of double-circuit line on same pole are the mutual inductances that need between the consideration double loop, and what have the greatest impact is the ground protection of double loop, i.e. zero-sequence current protection and ground distance protection.

The basic principle of double-circuit line on same pole protection configuration

Adopt at present the vertical direction of single command can correctly select tripping operation mutually with longitudinal distance protection to single line down, the single-phase fault single-hop also overlaps, and causes system stability to destroy for preventing to close in heterogeneous permanent fault to the serious impact of system, and heterogeneous fault three is jumped heavy.When taking place with the bar cross line fault, in general always there is the protection of a side to think heterogeneous fault and three jumpings, it is not heavy to cause double loop equal three to jump.As everyone knows, actual most of fault is a transient fault.

Therefore for improving the reliability of transmission of electricity; require relaying protection when cross line fault, can select tripping operation mutually; as the IAIIBG fault takes place; the A phase is jumped in I loop line both sides; the B phase is jumped in II loop line both sides, also has four still can carry bigger power in operation after the tripping, and reclosing moves afterwards; be generally the transient fault successful reclosing, recover normal double loop operation.Even have only a loop line successful reclosing also can keep loop line operation.

The differential current protection should be as the first-selection protection of double-circuit line on same pole.The differential current protection has a series of advantage; as external fault there being absolute selectivity; do not react load, not influenced by system oscillation, the natural phase ability of selecting is arranged; when open-phase operation; still have good performance, both adapted to long line and also adapted to short-term, be not subjected to the influence of series compensation capacitor again; even also be the excellent protection that be worth to adopt on single loop line, Japanese differential current use commonplace.Acquisition very natural on double-circuit lines on the same pole is used, the place that does not also have special requirement to change.The differential current protection is by line configuring, and every loop line is established a cover protection on double-circuit line on same pole, and separate, this line three-phase current is only gathered in each protection, sends out trip signal to this line circuit breaker, also can not cut two loop lines with mistiming although misoperation takes place.This point meets the requirement of Wuxi meeting in 1991 fully.Adopt the differential current protection that the problem of double-circuit lines on the same pole protection is resolved satisfactorily.

Therefore should dispose two cover differential current protections to the every loop line of double-circuit lines on the same pole; in order to realize dualization of main protection, a cover differential current protection and is overlapped longitudinal distance protection and is constituted dualization main protection a kind of selection of can yet be regarded as when condition does not possess.Want when the subject matter of longitudinal distance protection is cross line fault correctly to select the fault phase of jumping this line, the phase-selecting method that only reacts the electric parameters of circuit one side can't be distinguished single line down of line end, cross line fault and double loop external fault.Because see it to be the fault of two loop line generation same types at circuit top.As when taking place near the cross line fault of circuit one side such as I loop line A phase, when the II loop line is the cross-line earth fault (being designated as IAIIBG) of B phase; the protection of only near fault side can be selected the fault phase of this line, all will be phase to phase fault (as 4 phase faults) and the protection of each loop line of opposite side of circuit is seen.The correct choosing of fault side far away must rely on mutually that nearly fault side sends by the phase locking or allow signal, each loop line should take 3 command channels in other words, so that by sending locking mutually or allowing signal.Should not take to simulate with 1 or 2 command channel the solution of 3 lockings or permission command signal, practice has proved like that and can reduce rapidity and fail safe.

Separate configurations is answered in the protection of every loop line in a word, causes double loop all cut to prevent a covering device malfunction, and single in addition loop line operation, maintenance can not influence the normal operation of another loop line.To longitudinal distance protection, should have 3 autonomous channels and divide phase command with transmission.The protection of every cover all should be furnished with the quick excision fast tripping protection of catastrophe failure (as power frequency variation impedance relay, impedance I section) and be with the distance protection and the zero-sequence current protection in time limit nearby that does not rely on passage except that main protection.

The zero-sequence mutual inductance of double-circuit lines on the same pole is bigger to the protection range influence of ground distance, and this should pay attention to from adjusting.End fault had sensitivity when the definite value of vertical connection distance and impedance II section should guarantee that double loop all moves, and the definite value of impedance I section should guarantee that end fault does not surmount when the hanging ground-wire of adjacent line maintenance both sides.The method that should not adopt the adjacent line zero-sequence current that this line ground distance is compensated, main cause is: a) introduce the electric parameters of adjacent line, unfavorable to operation maintenance; B) when this side adjacent line switch opens,, may cause the protection that does not rely on passage to surmount owing to can not get the zero-sequence current compensation of adjacent line; C) during single phase ground fault, owing to introduce the compensation of adjacent line zero-sequence current, this line phase earthing distance relay of the same name easily surmounts malfunction to adjacent line nearby.

Break down again during open-phase operation or when overlapping; near permanent fault or other phase fault of this line takes place former fault point often; therefore be provided with open-phase operation fault acceleration impedance II section, reclosing post acceleration impedance II section and zero-sequence current protection again in the protection; these protections do not rely on passage and there is sensitivity all fronts; though optionally may as if lose, be success fully through facts have proved.But consider the situation of cross line fault for double-circuit line on same pole, should consider that break down not malfunction or all non-full phase time one loop line of two loop lines of the non-full phase time adjacent line of this line coincides with the measure of another not malfunction of loop line of fault.Can adopt reclosing only to quicken the tripping phase of this line, open-phase operation fault is again quickened impedance II section band short time delay such as 120ms time-delay to guarantee selectivity.

Characteristics of the present invention are: the correct choosing that has solved any fault under 500kV and the following any operating mode of double-circuit lines on the same pole mutually and the fast trip problem.And taken into full account and existing interface and safety of construction and the convenience of protecting, pacifying equipment such as control, therefore had both the advance of technology and the feasibility of practical application.

1. the adaptive reclose scheme of Ti Chuing has fully absorbed existing scientific achievement, and the step of going forward side by side innovates.The solid theories foundation is arranged, and carried out a large amount of simulation calculation, dynamic simulation test and the checking of RTDS digital real-time emulation.Compare with domestic and international other coincidence schemes, this programme has following characteristics:

1) reclosing function reasonable distribution is in route protection and breaker protection, the information that makes full use of route protection realizes that no catastrophe failure is differentiated and the branch phase sequence overlaps strategy, overlaps outlet by breaker protection according to the state of itself and the matching relationship realization of adjacent switch;

2) adopt the mode only jump the fault phase, promptly only jump two-phase during this line phase to phase fault, but not three jump, making the contact that keeps the system two ends between age at failure to greatest extent has the maximum chances that can start reclosing, recovers the possibility of the normal operation of double loop;

3) reclosing of two loop lines is regarded as an integral body, adopted and divide phase sequence to close a floodgate, two loop line roads have only one to coincide simultaneously, have avoided coinciding with the impact that permanent heterogeneous fault causes system;

4) adopt no serious permanent fault criterion in the coincidence scheme first, further reduced coinciding with the impact of permanent fault system, after close side and close no longer coincidence after fault at offside.

Therefore, this programme has been kept the contact between system between age at failure to greatest extent, under the prerequisite of having avoided system's serious impact, has increased the chance that overlaps and the probability of successful reclosing greatly, have other schemes both at home and abroad incomparable superiority.

2. based on the importance of double loop, be to guarantee system safety operation, lower operation risk, keep existing protective device, as required still can be complete at any time, reliably put into operation.New protection has taken into full account the interface with existing protection, has avoided the influence to existing protective device.

3. putting into operation of new protection used and original protection basically identical in definite value and operation, makes dispatching management department and operation maintenance department be easy to maintenance management.

The transformation of measuring and calculating, control box and the breaker control circuit of CT secondary load has been finished at the scene, for putting into operation of new protection created condition; Transformation makes it to adapt to the normal operation of parallel lines on same tower circuit and conventional single back line under the various operating conditions to breaker protection.

Description of drawings

Fig. 1 is a reclosing according to phase order lock protection logic diagram

Fig. 2 is with the preferential reclosing protection of famous prime minister logic diagram

Fig. 3 is the preferential reclosing protection of a leading phase logic diagram

Fig. 4 is the preferential reclosing protection of the leading phase of a phase to phase fault circuit logic diagram

Fig. 5 is that single-phase earthing fault tripping phase voltage waveform instantaneous and permanent fault contrasts

Fig. 6 is transient fault fault phase terminal voltage figure of the present invention (no shunt reactor)

Fig. 7 is transient fault fault phase terminal voltage figure of the present invention (band shunt reactor)

Fig. 8 is the artificial single-phase earthing test of the present invention fault phase voltage, current waveform figure (band shunt reactor)

Embodiment

The selection of double-circuit line on same pole protection tripping operation mode

Conventional tripping operation mode is heterogeneous fault three jumpings of single-phase fault single-hop.The shortcoming of this scheme is to fail to keep to greatest extent the contact at system two ends when three wires and above cross line fault.For example when IAIIBCG three-phase three wires fault, have only the IBC two-phase in the cycle in operation, failed IIA to participate in mutually and form accurate three-phase operation at reclosing.And for example excision double loop when IABIIBCG three-phase four lead cross line faults fails to keep ICIIA two-phase operation and reclosing.

When therefore mainly relying on the double loop contact for two side systems, desirable tripping operation mode is only to excise the fault phase when fault, and different with routine is that phase to phase fault is jumped two-phase but not three-phase, is about to non-fault and remains the continuation operation mutually, and carry out reclosing.As previously mentioned, this tripping operation mode can keep the system two ends in the contact of reclosing in the cycle to greatest extent, and the chance that has more starting to overlap.

Coinciding with the fault usual manner is three jumpings, and no matter be to coincide with single-phase or heterogeneous fault.Can desirable mode be to coincide with fault still only to jump the fault phase, reexamine the remaining sound phase of two loop lines and constitute accurate three-phase operation.For example when IAIIBCG takes place when if only excise the fault phase, then electric power can also be through sound three-phase (IBCIIA) transmission.If permanent fault, also operation like this (be called " accurate three-phase " operation).If permanent IAIIBG fault then has IBCIIAC four to perfect phase, for keep three symmetrical also will from the C of two loop lines mutually excision one phase, reach accurate three-phase operation.Obvious this mode still can keep a loop line (to two end systems) operation to the permanent cross line fault of major part.

All do not have to adopt the mode of " accurate three-phase " operation at present both at home and abroad, because accurate three-phase operation will bring many problems: a) as shunt reactor is arranged on the circuit, then the little reactance of neutral point will be passed through electric current for a long time; B) how the dispatcher will return to normal operating mode from accurate three-phase operation mode; C) dispose separately by every loop line as protection, the performance of the protection that then will deteriorate significantly under accurate three-phase operation mode is as losing the zero sequence backup protection; D) the inconsistent operation of the long-term three-phase of switch etc. unless the signal of double loop is all introduced, promptly needs two loop lines as the one cover protection of a configured in one piece.

In a word, the mode that the tripping operation mode can adopt the heterogeneous fault three of single-phase fault single-hop to jump is that phase to phase fault is jumped two-phase to improve the reliability of transmission of electricity as far as possible and should adopt the mode of only jumping the fault phase to important double-circuit line on same pole.But coincide with then three jumpings always of fault, should not adopt to be integrated into " accurate three-phase " operation mode.

The selection of double-circuit line on same pole reclosing mode

China is the normal single-pole reclosing that adopts on the transmission line of the above electric pressure of 220kv, and promptly single-phase tripping allows to overlap the three-phase tripping and do not allow to overlap.Mainly be to still have two-phase in operation after considering single-phase tripping, the both sides interconnection is comparatively tight, can not examine and determine and unconditionally overlap the same period, coinciding with fault in addition also only is to overlap to do single-phase permanent fault, has avoided coinciding with the serious impact of heterogeneous fault to system.But consider the situation of cross line fault when on double-circuit line on same pole, using,, still can not avoid coinciding with the two-phase permanent fault even then adopt the substance mode.As the IAIIB permanent fault has taken place, and two loop lines all are the single-hop substances, the words of Chong Heing are to coincide with the AB phase to phase fault for system then simultaneously.Certain this mode has avoided coinciding with three-phase fault.

If on double-circuit line on same pole two loop lines are seen substance mode to be achieved as a loop line, then only requiring has two different name leads to perfect in six leads, can allow to overlap.This coincidence system is so-called multiphase reclosing mode, uses comparatively extensive in Japan.This mode cooperates the tripping operation mode of only jumping fault phase (phase to phase fault jumping two-phase) that more coincidence chance is then arranged, but may coincide with two-phase even three-phase permanent fault.

On the basis of multiphase reclosing mode,, the scheme of reclosing according to phase order is proposed for avoiding coinciding with heterogeneous fault.Basic thinking is that the reclosing of two loop lines is regarded as an integral body, and two loop lines have only one overlapping simultaneously, and successful reclosing closes another phase again.Unsuccessful reclosing then three is jumped this circuit, check that afterwards another loop line then continues to overlap as possessing the substance condition, otherwise three jumps.

Multiphase reclosing all is to be based upon protection only to jump on the fault basis mutually with the reclosing according to phase order lock; therefore has the contact that keeps the system two ends between age at failure to greatest extent; the maximum chances that can start reclosing is arranged, recover the possibility of the normal operation of double loop, referring to the comparison of table 4.Adopt the reclosing according to phase order lock then to avoid coinciding with heterogeneous permanent fault fully, superiority is more arranged.For the three-phase fault of a loop line, three jump the back just should not overlap again, main cause be three-phase fault probability seldom and mostly to be the people be the permanent fault that causes.

Table 4 single-pole reclosing and multiphase reclosing overlap the comparison of chance

Annotate: shade is the fault phase, " φ ": overlap "-": need not overlap, " * " is for comparing the situation that can start coincidence of increase with conventional substance.Multiphase reclosing or reclosing according to phase order lock are to consider to have in two loop lines that two different names are sound mutually allows to overlap (accurate substance) in the table, but to the equal tripping of three-phase in the loop line then this line do not overlap.

Reclosing should be pressed line configuring, for the operation information of multiphase reclosing and comprehensive two loop lines of reclosing according to phase order lock needs, whether satisfies the sound mutually condition of two different names to differentiate.The operation conditions that contains this line in the route protection, for obtaining the information of another loop line, the digital communication that increases between the protection of two loop lines just can realize that its advantage is the wiring that does not increase device, the secondary circuit of two loop lines does not intersect, and is convenient to operation maintenance.In the time can not obtaining the information of adjacent line for a certain reason, should be able to transfer conventional single-pole reclosing automatically to, it is phase to phase fault three jumpings that the tripping operation mode of protection this moment should change to usual manner automatically.Simultaneously, should avoid coinciding with simultaneously the two-phase permanent fault.

Reclosing is the information that can make full use of route protection when adopting circuit TV by another advantage of line configuring, realizes the fault-free coincidence or do not have the catastrophe failure side overlapping earlier, avoids the permanent fault that coincides with fault or coincide with outlet.

Double-circuit line on same pole overlaps in proper order by the no catastrophe failure that combines

The strategy of 1 reclosing according to phase order

For avoiding coinciding with heterogeneous permanent fault, require two loop line roads to have only one to coincide simultaneously.Therefore protective device wants the operation information of comprehensive two loop lines to overlap by certain rule ordering.Coincidence is determined as follows in proper order:

1) overlap and can overlap simultaneously with the famous prime minister is preferential, its reason is:

Even a) coincide with permanent fault, be to coincide with single-phase fault for system;

B) recover the operation of phase shortage phase as early as possible;

C) can reduce whole reclosing time.

2) leading phase of phase to phase fault circuit preferentially overlaps, and its objective is that a loop line coincides with fault three another loop lines of jumping back and still possesses substance condition continuation coincidence.As the IABIIC fault, overlap IA earlier, even coincide with three jumpings of fault I loop line, but the AB that II returns is still sound, can close IIC again; And if close IIC earlier, as coincide with three jumpings of fault II loop line, the only surplus IC of two loop lines then, I returns and can not overlap again, has lost the chance that overlaps.

3) leading phase preferentially overlaps, and purpose is to allow each preferential mutually probability identical (probability of supposing each phase fault is identical) that overlaps.No matter be that a line down or cross line fault all overlap by the preferential order of leading phase.

For example: the IABIIBC fault, the B of two loop lines preferentially overlaps mutually, closes IIC afterwards, closes IA at last;

The IABIIC fault is closed the leading phase IA of phase to phase fault earlier, closes IB afterwards, closes IIC at last;

The IAIIC fault is closed IIC earlier, closes IA again;

The IAB fault is closed IA earlier, closes IB again.

Table 5 has provided under various failure conditions by this tactful reclosing order

The coincidence order of table 5 reclosing according to phase order lock

Annotate: shade is the fault phase, " φ ": overlap "-": need not overlap or inoperative coincidence.The reclosing according to phase order lock is to consider to have in two loop lines that two different names are sound mutually allows to overlap (accurate substance) in the table, but to the equal tripping of three-phase in the loop line then this line do not overlap.

As can be seen from the table, reclosing according to phase order lock scheme is compared with the multiphase reclosing scheme in most of the cases increases single shot reclosing (about 200ms) at interval, just can avoid coinciding with heterogeneous permanent fault, only under complex fault situation seldom, need to increase by two reclosings at interval.The time of non-full phase does not have too many increase, and the circuit breaker three-phase should be worth much larger than this inconsistent operate time.

The differentiation of no catastrophe failure

Reclosing according to phase order has avoided coinciding with heterogeneous permanent fault; large power supply is exported single-phase fault through long line transmission of electricity when coinciding with large power supply; also can produce very big impact to system; when adopting circuit TV, utilize the voltage characteristic of tripping phase and the action message of protection, can determine whether near the permanent fault the outlet has taken place; as being; then take to overlap earlier, coincide with fault offside three and jump the just no longer coincidence of this side, and if then this side of successful reclosing overlaps by fault side far away.

After the tripping of fault phase, the sound disconnection between the phase relatively exists capacitor coupling voltage and mutual voltage.Having on the circuit of shunt reactor compensation, after the power supply expulsion of arc of diving went out, the stored electromagnetic energy of each energy-storage travelling wave tube was decayed (damping time constant is about 1 second) in free-running mode by the natural frequency (30-40Hz) of network.Therefore in the voltage that disconnects the phase two ends, also has this free component.

When permanent earth fault takes place, capacitor coupling voltage will be very little, and the transient state free component is intact with very fast decay, and is more little the closer to the fault point mutual voltage, and far-end will induce certain voltage when load current is big.Therefore can determine whether to take place permanent earth fault nearby by following voltage criterion:

U _φ＞Uzd

Satisfy this voltage criterion and think there is not generation permanent earth fault nearby.

When the earth-free fault of two-phase has taken place, the terminal voltage criterion will satisfy, and can not distinguish instantaneity or permanent fault.Even a phase time does not break down for system but permanent fault ought be closed, the voltage of another tripping phase will be basic identical with that voltage mutually that has closed this moment, and transient fault there is no this feature, and therefore the method that overlaps by minute phase sequence is easy to distinguish.As the earth-free permanent fault of IAIIB cross-line has taken place, and closing IA earlier, successful reclosing recovers the three-phase operation of I loop line, the B phase voltage (line voltage distribution) that this moment, II returned will be basic identical with the A phase voltage, this moment, IIB just should not overlap again, and answered three jumpings, kept the I loop line operation of successful reclosing.

When the transient fault that takes place as IAIIBCG; kept the accurate three-phase operation of IBCIIA after the tripping; if circuit replaces fully; the capacitor coupling voltage and the mutual voltage of sound symmetry three relative tripping phases will be very little; can not satisfy voltage criterion; both sides are all thought serious permanent fault has taken place and are not overlapped, and for remedying the deficiency that adopts the terminal voltage criterion, should make full use of the information of route protection.As satisfy following arbitrary condition and think there is not generation catastrophe failure nearby, can overlap:

A) phase voltage during fault, voltage between phases are bigger;

B) do not rely on the quick protection of passage less than action (as impedance I section, power frequency variation impedance);

C) the range finding result is bigger.

In sum, overlap scheme by the no catastrophe failure that combines and to keep system two ends contact between age at failure to greatest extent, improve the chance that overlaps, avoid coinciding with serious permanent fault.

As shown in Figure 1: reclosing according to phase order lock characteristics:

Reclosing according to phase order

Noncritical failure overlaps;

Three-phase fault (three jump) is not heavy;

Order is when overlapping, and the both sides exchange message is to avoid coinciding with permanent fault twice;

I) reclosing according to phase order

Require: two loop line roads have only one to coincide simultaneously;

Protective device wants the operation information of comprehensive two loop lines to overlap by certain rule (strategy) order;

Concrete strategy:

Overlap strategy one: shown in Figure 2, overlap and can overlap simultaneously with the famous prime minister is preferential

In Fig. 2 system, I loop line AB, II loop line A phase fault take place in circuit, should close the A phase earlier, can the fastest recovery system power normally carry.

Overlap strategy two: as shown in Figure 3, leading phase preferentially overlaps; Overlap in separate order: A ← B ← C ← A such as Fig. 3 system, I loop line C, II loop line A phase fault take place in circuit, and according to overlapping separate order, C is ahead of A, therefore close I loop line C earlier.

Overlap strategy three: as shown in Figure 4, the leading phase of phase to phase fault circuit preferentially overlaps:

In Fig. 4 system, I loop line BC, II loop line A phase fault take place in circuit, according to overlapping separate order, for I line down phase B mutually and C in, B ultrasonic is preceding in C, therefore I loop line B is mutually preferential, the preferential B of I loop line compares with II loop line A, and A is mutually preferential, and therefore final coincidence result closes the A of II loop line earlier, close the B of I loop line again, close the C of I loop line at last.

Ii) non-serious permanent fault overlaps

Purpose: improve the successful reclosing probability; Avoid coinciding with serious permanent fault instantaneous permanent fault criterion has been introduced in the impact of system in the adaptive reclose logic:

No catastrophe failure overlaps the theoretical foundation of differentiating: after single-phase tripping operation of the circuit with distributed constant or two-phase tripping operation, non-fault exists mutual voltage and capacitor coupling voltage between disconnecting mutually relatively.For fault of different nature (instantaneity or permanent), mutual voltage has the different forms of expression with capacitor coupling voltage.

Fig. 5 is that single-phase earthing fault tripping phase voltage waveform instantaneous and permanent fault contrasts

In the adaptive reclose logic, introduced serious noncritical failure criterion: satisfy following arbitrary condition and think catastrophe failure does not take place, can overlap:

1) during fault phase voltage, voltage between phases all greater than 50% rated voltage;

2) not action of impedance I section, power frequency variation impedance;

3) the range finding result is greater than 40% total track length.

Instantaneous permanent fault criterion and catastrophe failure criterion combine, and whether can reliably judge nature of trouble is serious permanent fault, have determined the coincidence order of circuit both sides protection.

Under the transient fault situation, the electric characteristic of line influence voltage has or not the installing shunt reactor relevant with circuit, and self adaptation overlaps to be introduced based on the fault point blow-out criterion of voltage magnitude in conjunction with the voltage higher harmonic content;

The theoretical foundation of blow-out criterion is: for the circuit of no shunt reactor, when circuit generation asymmetry transient earthing fault, after the two ends tripping of line fault phase, owing to perfect the electric capacity and the inductance coupling high effect of relative fault tripping phase, cause continuous the extinguishing and burning of electric arc, the secondary arc current waveform is electric arc and repeats to puncture character, and the wave distortion of recovery voltage is bigger.

Shown in Figure 6, be by transient fault fault phase terminal voltage (no shunt reactor) that Fig. 6 is the complete blow-out when 518ms of fault phase terminal voltage waveform fault point when with the circuit of shunt reactor the ground connection transient fault not taking place, recovery voltage is sinusoidal waveform after the blow-out.For transient fault, must determine the complete blow-out of electric arc, and after arc road ambient air medium dielectric strength returns to a certain degree, could overlap.

For secondary arc, in each power frequency period, when rising to certain level backarc road, the recovery voltage amplitude just punctures, must contain high order harmonic component therebetween, for the ground connection transient fault, the triple-frequency harmonics content of arc voltage is about about 30% of first-harmonic content in the arcing process, and quintuple harmonics content is about about 20% of first-harmonic content, so this programme proposes the fault point blow-out criterion of no shunt reactor circuit:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="U\; fd"\; filenames="C20041006496000222.png,C20041006496000232.png"\; state="\{\{state\}\}">U</figure-callout>}}_{\mathrm{fd}}\&GreaterEqual;{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20041006496000221.png"\; state="\{\{state\}\}">k</figure-callout>}}_2*U_N\\ (U_{\mathrm{fd}3}+U_{\mathrm{fd}5})<k_3*{\mathrm{<figure-callout\; id="1"\; label="U\; fd"\; filenames="C20041006496000222.png,C20041006496000232.png"\; state="\{\{state\}\}">U</figure-callout>}}_{\mathrm{fd}}\end{array}\right.$

k ₂Desirable 0.1; k ₃Desirable 0.2;

U _Fd1, U _Fd3, U _Fd5Be respectively the amplitude of first-harmonic, three times and the quintuple harmonics of tripping phase voltage.

For the circuit that shunt reactor is arranged, the very fast rising of recovery voltage after fault disappears, because the frequency of free oscillation voltage is different with power frequency, beat frequency phenomenon appears in recovery voltage.Fig. 5 is Chongqing of Sichuan 500KV electrical network band shunt reactor A phase voltage, the current waveform during the mutually single-phase instantaneous artificial earthing's short circuit test of A for the first time, and in latter two cycle of fault phase tripping, electric arc just extinguishes.

Fig. 7 and shown in Figure 8: transient fault fault phase terminal voltage (band shunt reactor) and artificial single-phase earthing test fault phase voltage, current waveform figure (band shunt reactor):

For permanent earth fault, do not contain free oscillation voltage in the fault phase terminal voltage, have only the inductance coupling high voltage of the relative fault phase of non-fault, therefore for continuous earth fault nearby, the amplitude that disconnects phase voltage is very little; For the far-end permanent earth fault, the amplitude that disconnects phase voltage may be bigger.

For the circuit that shunt reactor is arranged, because the effect of the little reactor of neutral point, earth point electric arc will extinguish very soon behind the fault phase trip, therefore needn't differentiate blow-out constantly by calculating harmonic content, promptly only keeps formula 3; Because the influence of free oscillation voltage contains low frequency component in the fault phase terminal voltage, and the voltage magnitude that is obtained by fourier algorithm according to formula 3 has bigger fluctuation, this can head it off by the mean value of choosing certain data window data in addition.

Therefore, for having the shunt reactor circuit, free oscillation voltage occurred after the blow-out of fault point, therefore disconnected the phase voltage amplitude and have than great fluctuation process, the blow-out criterion that is applicable to the shunt reactor circuit that this programme proposes is:

U _{fd1_ave}≥k ₄*U _N

k ₄Desirable 0.2; U _{Fd1_ave}Mean value for fundamental voltage.

The present invention program should be the preferred plan that is fit to China's national situation to important double-circuit line on same pole.This scheme is sent on the imperial 500KV double-circuit lines on the same pole of system's flood at ertan hydropower station and has been obtained application.

The present invention is provided with backup protection:

1) should dispose the quick excision fast tripping protection of catastrophe failure (as power frequency variation impedance relay, impedance I section) nearby that does not rely on passage;

2) stage distance protection;

3) zero-sequence current protection.

Comprehensive, reclosing should be able to adapt to multiple different coincidence system according to the requirement of primary system, i.e. single-pole reclosing, three-phase reclosing, composite auto-reclosing, reclosing according to phase order lock;

In that primary system is stable when requirement is arranged, reclosing should adopt the reclosing according to phase order lock.At this moment, the fault phase is only jumped in protection; Three-phase tripping operation when coinciding with fault; The double-circuit lines on the same pole road relaying protection of 220KV and above system is had cross line fault select the phase trip avoidance function, only quicken the tripping phase during open-phase operation; The reclosing of double-circuit lines on the same pole is not recommended the shared reclosing device of double-circuit lines on the same pole by line configuring.

For preventing that coinciding with heterogeneous permanent fault adopts reclosing according to phase order, promptly in order, successively divide the tripping phase that coincides;

After double-circuit lines on the same pole breaks down, just allow when having at least two different names to perfect mutually in the double loop to overlap, otherwise, all trippings of two loop lines; The corresponding preferential coincidence of the tripping of the same name of two loop lines; Cross line fault takes place in the double-circuit lines on the same pole road, and behind a loop line successful reclosing, the reclosing of another loop line is provided with the measure that prevents that successful reclosing circuit from breaking down once more.The relaying protection of double-circuit lines on the same pole and reclosing are not considered or or " accurate three-phase " operational mode of removal system.

Claims (5)

1. the reclosing method of a transmission line, method to the relaying protection of double-circuit lines on the same pole road is: the independent configuration protection in every loop line road of double-circuit lines on the same pole, the main protection on double-circuit lines on the same pole road is adopted the differential current protection or is had the pilot protection of branch phase command, for various forms of single line downs and cross line fault in the district, all should select the jumping fault to realize adaptive reclose mutually: a kind of adaptive reclose that when transmission line breaks down, is applied to high pressure and extra high voltage network, route protection is accurately selecting on the basis of jumping the fault phase, carry out reclosing according to phase order in conjunction with no permanent fault criterion: promptly in order, successively divide the tripping phase that coincides; After double-circuit lines on the same pole breaks down, just allow when having at least two different names to perfect mutually in the double loop to overlap, otherwise, all trippings of two loop lines; Jump fault mutually to protect accurate choosing; During the transmission line single-phase fault, when phase to phase fault and three-phase fault, all only the fault phase is jumped in choosing, rather than phase to phase fault three is jumped; The operation information that it is characterized in that comprehensive two loop lines of protective device overlaps by following rule ordering: coincidence by dividing phase sequence to overlap, overlaps and overlaps simultaneously with the famous prime minister is preferential in proper order; The leading phase of phase to phase fault circuit preferentially overlaps; Leading phase preferentially overlaps; Determined whether to take place fault point permanent earth fault nearby: U by tripping phase voltage criterion _φ＞Uzd, U _φBe the tripping phase voltage, Uzd is a setting value, satisfies this voltage criterion and thinks nearby the permanent earth fault of not breaking down a little.

2. by the reclosing method of the described transmission line of claim 1, it is characterized in that, overlap, determine whether to have taken place permanent earth-free fault by following voltage criterion based on minute phase sequence for alternate earth-free permanent fault:

$|{\stackrel{\&CenterDot;}{U}}_P+{\stackrel{\&CenterDot;}{U}}_Y|>k_1*|{\stackrel{\&CenterDot;}{U}}_P-{\stackrel{\&CenterDot;}{U}}_Y|$

k ₁Get 4-6;

Be respectively the three-phase voltage vector, behind arbitrary combined floodgate mutually,, then be judged to alternate earth-free permanent fault, no longer continue to send out the order of phase-splitting reclosing if system satisfies the following formula condition, It is respectively the three-phase voltage vector.

3. by the reclosing method of claim 1 or 2 described transmission lines, it is characterized in that under the transient fault situation fault point reclosure time that do not automatically prolong during blow-out as yet, until the fault point blow-out, to improve the successful reclosing probability; For no shunt reactor circuit, during overlapping, self adaptation introduces based on the fault point blow-out criterion of voltage magnitude in conjunction with the voltage higher harmonic content; The blow-out criterion is:

$\left\{\begin{array}{c}{U}_{\mathrm{fd}1}\&GreaterEqual;k_2*U_N\\ (U_{\mathrm{fd}3}+U_{\mathrm{fd}5})<k_3*U_{\mathrm{fd}1}\end{array}\right.$

k ₂Get 0.1-0.2; k ₃Get 0.2-0.4;

U _Fd1, U _Fd3, U _Fd5Be respectively the amplitude of first-harmonic, three times and the quintuple harmonics of tripping phase voltage; For having the shunt reactor circuit, free oscillation voltage has appearred after the blow-out of fault point, and therefore disconnect the phase voltage amplitude and have than great fluctuation process, the blow-out criterion is:

U _{fd1_ave}≥k ₄*U _N

k ₄Get 0.2-0.4; U _{Fd1_ave}Be the mean value of fundamental voltage, U _NIt is neutral point voltage.

4. by the reclosing method of claim 1 or 2 described transmission lines; it is characterized in that reclosing is by line configuring; the relative independentability and the integrality that keep double loop protection and reclosing; automatically transfer conventional reclosing when service conditions does not satisfy to when self adaptation overlaps, it is phase to phase fault three jumpings that the tripping operation mode of protection this moment should change to usual manner automatically.

5. by the reclosing method of claim 1 or 2 described transmission lines, it is characterized in that the operation information of comprehensive two loop lines of reclosing according to phase order lock needs, whether satisfy the sound mutually condition of two different names to differentiate; The operation conditions that contains this line in the route protection for obtaining the information of another loop line, is carried out information interaction by the optical fiber connection between the protection of homonymy double loop, and the protection passage adopts optical fiber or Digital Microwave channel transfer protection information.

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