CN104868451B - Realize GIS fault precisely to excise and the bus protection algorithm of automatic recovery of power supply - Google Patents

Abstract

The invention discloses a kind of GIS of realization fault precisely to excise and the bus protection algorithm of automatic recovery of power supply, comprising: calculate bus differential current, bus differential current and interval differential current among a small circle on a large scale respectively; According to the whether action of large poor ratio element, distinguish bus external area error and bus troubles inside the sample space; When large poor ratio element movement, by little poor ratio element, whether action determines which section bus is fault occur in; Whether action determines between-failures to clearance ratio difference element; According to the action situation of large poor ratio element, little poor ratio element and clearance ratio difference element, failure judgement type also makes response to fault.Beneficial effect of the present invention: energy is failure judgement position accurately; quick excision isolated fault, when preventing monospace internal fault, bus protection is by equal for all connection elements tripping, ensure that the selectivity of bus protection action; reduction accident scope, improves system run all right.

Description

Realize GIS fault precisely to excise and the bus protection algorithm of automatic recovery of power supply

Technical field

The present invention relates to Relay Protection Technology in Power System field, particularly a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply.

Background technology

When electric power system is broken down; the selectivity of relaying protection requires in minimum scope, may be minimum to systematic influence place; realize the control operation of circuit breaker; fault is opened from system break; with the development of termination failure or systematic failures, in guarantee system to greatest extent, no failure part still can continue safe operation.Bus protection action to excise on fault bus connect whole element; once there is erroneous judgement or malfunction in bus protection; light then lose load, affect device security, heavy then cause large-area power-cuts, even cause system stability problem to cause operation of power networks to be collapsed and disintegrate.Further investigation bus protection selectivity stroking technique and principle, change traditional extensive busbar fault diagnosis discrimination model, control large scale electric network ability to lifting, improve system run all right, Accident prevention expands significant.

The route protection now run and the algorithm principle of bus protection and secondary circuit design; all according to power grid GIS equipment actual conditions; namely circuit breaker line side, each interval and bus bar side all configure current transformer; line side electric current introduces bus protection; bus bar side current lead-ins road is protected; by the intersection of protection range, ensure that any position failures of element such as circuit, bus, circuit breaker, current transformer all have protection act tripping circuit breaker to excise.Particularly break down between line side and bus bar side current transformer, route protection and the equal action of bus protection, ensure that fault is reliably excised.Though this configuration ensure that reliability, selectivity requirement cannot be met.Break down between line side and bus bar side current transformer; still belong to monospace internal fault; it not real busbar fault; fault between line side current transformer and circuit breaker, only needing to pull open monospace circuit breaker can isolate, fault between circuit breaker and bus bar side current transformer; only need to pull open monospace disconnecting link can isolate; now run bus protection action and bus is joined the equal tripping of all elements, in fact cause fault coverage to expand, lose selectivity.

Summary of the invention

Object of the present invention is exactly to solve the problem; propose a kind of GIS of realization fault precisely to excise and the bus protection algorithm of automatic recovery of power supply; the method arranges the little difference of bus accessing all interval bus bar side CT; access the large difference of bus of all septal line trackside CT; and the interval accessing each interval bus bar side CT and line side CT is differential; according to three differential computational discrimination results, accurate fault point position, and adopt different fault isolation schemes for diverse location fault.

For achieving the above object, the present invention adopts following technical scheme:

Realize GIS fault precisely to excise and the bus protection algorithm of automatic recovery of power supply, it is characterized in that, comprise the following steps:

(1) for double-bus or two mother partition main electrical scheme, to suppose on two buses that each linkage unit is that to flow out sense of current from bus be positive direction; Calculate bus differential current, bus differential current and interval differential current among a small circle on a large scale respectively, according to bus differential current, bus differential current and the interval differential current among a small circle on a large scale calculated, judge the whether action of corresponding ratio element;

(2) according to the whether action of large poor ratio element, bus external area error and bus troubles inside the sample space is distinguished; When large poor ratio element movement, by little poor ratio element, whether action determines which section bus is fault occur in; Whether action determines between-failures to clearance ratio difference element;

(3) according to the action situation of large poor ratio element, little poor ratio element and clearance ratio difference element, failure judgement type also makes response to fault;

In described step (3); if break down between bus bar side CT to bus; differential action on a large scale; differential action among a small circle; all intervals are differential is all failure to actuate; judge that route protection is failure to actuate really as busbar fault, bus protection tripping bus connects all elements and jumping circuit offside circuit breaker far away.

In described step (1), bus differential current calculating on a large scale scope is all septal line trackside CT; Bus among a small circle differential current calculating scope is all interval bus bar side CT; It is between each interval bus bar side CT and line side CT that interval differential current calculates scope.

The computational methods of described step (1) median generatrix differential current are on a large scale:

$I_{cd}=\left|{\stackrel{\·}{I}}_{1L}+{\stackrel{\·}{I}}_{2L}+\mathrm{...}+{\stackrel{\·}{I}}_{nL}\right|;$

In formula, represent each branch line trackside CT current phasor.

The computational methods of described step (1) median generatrix differential current are among a small circle:

(1) I female little spill current: $I_{cd1}=\left|{\stackrel{\·}{I}}_{1B}{S}_{11}+{\stackrel{\·}{I}}_{2B}{S}_{12}+\mathrm{...}+{\stackrel{\·}{I}}_{nB}{S}_{1n}+{\stackrel{\·}{I}}_{ML1}{S}_{ML}\right|;$

(2) II female little spill currents: $I_{cd2}=\left|{\stackrel{\·}{I}}_{1B}{S}_{21}+{\stackrel{\·}{I}}_{2B}{S}_{22}+\mathrm{...}+{\stackrel{\·}{I}}_{nB}{S}_{2n}-{\stackrel{\·}{I}}_{ML2}{S}_{ML}\right|;$

In formula, represent each branch road bus bar side CT current phasor; represent the female side of mother I, II female side CT current phasor respectively; S ₁₁, S ₁₂..., S _1nrepresent the female disconnecting link position of each branch road I; S ₂₁, S ₂₂..., S _2nrepresent the female disconnecting link position of each branch road II; S _mLrepresent bus paired running state.

In described step (1), the computational methods of interval differential current are:

(1) branch road interval differential current:

$L_{cdi}=|{\stackrel{\·}{I}}_{iB}+{\stackrel{\·}{I}}_{iL}|$

Wherein, i=1,2 ... n; be respectively i-th interval bus bar side and line side CT secondary current vector; I _cdibe i-th branch road interval differential current;

(2) mother interval differential current:

$I_{cdML}=|{\stackrel{\·}{I}}_{ML1}+{\stackrel{\·}{I}}_{ML2}|;$

Wherein, be respectively mother I bus bar side and II bus bar side CT secondary current vector; I _cdMLfor mother interval differential current.

The concrete grammar of described step (3) is:

(1) if break down between line side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay and is first failure to actuate, after the switch tripping of circuit both sides, fault point isolate, on a large scale differential, among a small circle the differential equal indifference stream in differential and all intervals return, be judged as line side dead-zone fault, bus protection is failure to actuate, and other elements of bus continue to run;

(2) if break down between bus bar side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay and is first failure to actuate, after the switch tripping of circuit both sides, fault point still exists, the differential difference stream that still has of differential and between-failures does not return on a large scale, differentially among a small circle still to be failure to actuate, be judged as bus bar side dead-zone fault, other elements of bus protection action tripping bus, through the isolated fault of predetermined time delay tripping between-failures bus bar side disconnecting link after bus tripping, other bus bar elements use bus reclose sequence to close non-faulting interval circuit breaker, bus continues to run.

The concrete grammar of described step (3) is:

If break down between bus and II bus bar side CT, on a large scale differential action, to be differentially among a small circle failure to actuate, mother interval differential action, judges really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, II is female littlely differentially makes tripping II bus, and I bus normally runs;

If break down between bus and I bus bar side CT, on a large scale differential action, to be differentially among a small circle failure to actuate, mother interval differential action, judges really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, I is female littlely differentially makes tripping I bus, and II bus normally runs.

The concrete grammar of described step (3) is:

If break down between the L2 line side CT of the L2 line side CT of circuit transformer station A and circuit transformer station B, differential, differential and all intervals are differential is all failure to actuate, route protection action tripping circuit both sides switch among a small circle on a large scale.

Bus bar side CT is installed near circuit breaker air chamber place in 1 disconnecting link air chamber, or installs bus bar side CT additional separately between 1 disconnecting link air chamber and circuit breaker air chamber.

The invention has the beneficial effects as follows:

The realized GIS fault that the present invention proposes precisely is excised and the bus protection algorithm of automatic recovery of power supply; compared with traditional protection philosophy; the method energy accurately failure judgement position; quick excision isolated fault; when preventing monospace internal fault, bus protection is by equal for all connection elements tripping; ensure that the selectivity of bus protection action, reduction accident scope, improves system run all right.

The bus protection new principle that the present invention proposes and regulation and control operation control program, achieve when being precisely judged as fault between line side current transformer and circuit breaker, protection act only tripping between-failures circuit breaker realizes Fault Isolation; When being precisely judged as fault between circuit breaker and bus bar side current transformer, automatic/hand pulls open monospace disconnecting link isolated fault, and all non-faulting that bus runs perfect element maintenance and run; When being precisely judged as real busbar fault, by all connection elements of bus protection correct operation tripping.

The inventive method solve inside, current GIS operational outfit monospace break down and the non-selective action of bus protection, tripping all bus Connection Elements expansion accident range problem; fundamentally change traditional extensive busbar fault diagnosis discrimination model; avoid the serious consequence causing system crash to disintegrate, ensure that power grid operation.Solve and control the key problem of bulk power grid in the urgent need to process, there is extremely strong actual application value, possess boundless industry and popularize prospect in an all-round way.

Accompanying drawing explanation

Fig. 1 is traditional double bus special mother tie;

Fig. 2 is bus protection new principle schematic diagram of the present invention;

Fig. 3 is that bus bar side CT of the present invention is arranged on Z1 air chamber schematic diagram;

Fig. 4 is embodiment of the present invention abort situation analysis chart;

Fig. 5 is embodiment of the present invention fault location and process chart.

Embodiment

Below in conjunction with accompanying drawing and example, the present invention will be further described.

1, conventional busbars protection philosophy

Sectionalized bus, as the main electrical scheme such as double-bus, two mother partitions as shown in Figure 1, differential protection use large poor percentage differential element as troubles inside the sample space discriminating element; Use little poor percentage differential element as fault bus selectors.Namely by the whether action of large poor ratio element, bus external area error and bus troubles inside the sample space is distinguished; When large poor ratio element movement, by little poor ratio element, whether action determines which section bus is fault occur in.

The failure response behavior of conventional busbars protection philosophy and power failure range as follows:

(1) fault point (see k1 fault point in Fig. 1) between bus protection CT and circuit breaker

Bus protection and the equal action of route protection, tripping faulty line switch and other operation intervals of place bus, expand power failure range, only tripping circuit L2 both sides circuit breaker gets final product isolated fault.

(2) fault point (in see Fig. 1 k2 fault point) between circuit breaker and route protection CT

Bus protection and the equal action of route protection, tripping faulty line switch and place bus other run intervals, expand power failure range, only tripping circuit L2 both sides circuit breaker pull open I, II bus isolation switch and get final product isolated fault.

(3) fault point is at disconnecting link air chamber or bus (in see Fig. 1 k3 fault point)

Bus protection action, all operation intervals of tripping fault bus, do not expand power failure range.

2, the present invention realizes GIS fault and precisely excises and the bus protection algorithm of automatic recovery of power supply

As shown in Figure 2, percentage differential element is as troubles inside the sample space discriminating element on a large scale for the main electrical scheme such as double-bus, two mother partitions; Percentage differential element is as fault bus selectors among a small circle; Clearance ratio is differential as between-failures selectors.Namely by the whether action of large poor ratio element, bus external area error and bus troubles inside the sample space is distinguished; When large poor ratio element movement, by little poor ratio element, whether action determines which section bus is fault occur in; Whether action determines between-failures to clearance ratio difference element.

2.1 general principle

If two on bus each linkage unit be from bus flow out sense of current be positive direction, as shown in Figure 3.

First bus on a large scale differential computer capacity is all septal line trackside CT; Second bus among a small circle differential computer capacity is all interval bus bar side CT; The differential computer capacity in interval is between each interval bus bar side CT and line side CT.

Differential current formula on a large scale:

$I_{cd}=\left|{\stackrel{\·}{I}}_{1L}+{\stackrel{\·}{I}}_{2L}+\mathrm{...}+{\stackrel{\·}{I}}_{nL}\right|---\left(1\right)$

In formula, represent each branch line trackside CT current phasor.

Differential current formula among a small circle:

(1) I female little spill current: $I_{cd1}=\left|{\stackrel{\·}{I}}_{1B}{S}_{11}+{\stackrel{\·}{I}}_{2B}{S}_{12}+\mathrm{...}+{\stackrel{\·}{I}}_{nB}{S}_{1n}+{\stackrel{\·}{I}}_{ML1}{S}_{ML}\right|---\left(2\right)$

(2) II female little spill currents: $I_{cd2}=\left|{\stackrel{\·}{I}}_{1B}{S}_{21}+{\stackrel{\·}{I}}_{2B}{S}_{22}+\mathrm{...}+{\stackrel{\·}{I}}_{nB}{S}_{2n}-{\stackrel{\·}{I}}_{ML2}{S}_{ML}\right|---\left(3\right)$

In formula, represent each branch road bus bar side CT current phasor; represent the female side of mother I, II female side CT current phasor respectively; S ₁₁, S ₁₂..., S _1nrepresent the female disconnecting link position of each branch road I (0 represents that disconnecting link divides, and 1 represents that disconnecting link closes); S ₂₁, S ₂₂..., S _2nrepresent the female disconnecting link position of each branch road II; S _mLrepresent bus paired running state (0 represents split operation, and 1 represents paired running).

Branch road interval differential current formula:

$L_{cdi}=|{\stackrel{\·}{I}}_{iB}+{\stackrel{\·}{I}}_{iL}|---\left(4\right)$

Wherein, i=1,2 ... n; be respectively i-th interval bus bar side and line side CT secondary current vector; I _cdibe i-th branch road interval differential current.

Mother interval differential current formula:

$I_{cdML}=|{\stackrel{\·}{I}}_{ML1}+{\stackrel{\·}{I}}_{ML2}|---\left(5\right)$

Wherein, be respectively mother I bus bar side and II bus bar side CT secondary current vector; I _cdMLfor mother interval differential current.

The fault actions criterion of the female little spill current of the large spill current of bus, I, II female little spill current, branch road interval differential current and mother interval differential current is respectively:

$\left\{\begin{array}{c}\left|I_{cd}\right|>I_{cdzd}\\ \left|I_{cd}\right|>K\underset{j=1}{\overset{m}{\mathrm{\Σ}}}\left|I_{jL}\right|\end{array}\right.;\left\{\begin{array}{c}\left|I_{cd1}\right|>I_{cdzd}\\ \left|I_{cd1}\right|>K\underset{j=1}{\overset{m}{\mathrm{\Σ}}}\left|I_{jB}\right|\end{array}\right.;\left\{\begin{array}{c}\left|I_{cd2}\right|>I_{cdzd}\\ \left|I_{cd2}\right|>K\underset{j=1}{\overset{m}{\mathrm{\Σ}}}\left|I_{jB}\right|\end{array}\right.;\left\{\begin{array}{c}\left|I_{cdi}\right|>I_{cdzd}\\ \left|I_{cdi}\right|>K\left(\left|{\stackrel{\·}{I}}_{iB}\right|+\left|{\stackrel{\·}{I}}_{iL}\right|\right)\end{array}\right.;\left\{\begin{array}{c}\left|I_{cdML}\right|>I_{cdzd}\\ \left|I_{cdML}\right|>K\left(\left|{\stackrel{\·}{I}}_{ML1}\right|+\left|{\stackrel{\·}{I}}_{ML2}\right|\right)\end{array}\right.;$

Wherein, K is ratio brake coefficient; I _jLfor the line side CT electric current of a jth connection branch road; I _jBfor the bus bar side CT electric current of a jth connection branch road; I _cdzdfor differential current starts definite value.

2.2 failure response

(1) if break down (in Fig. 2 k1 point failure) between line side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay (the switch motion quenching time of hiding is as 160MS) and is first failure to actuate, after the switch tripping of circuit both sides, fault point isolates, differential on a large scale, the differential equal indifference stream in differential and all intervals returns among a small circle, be judged as line side dead-zone fault, bus protection is failure to actuate, other elements of bus continue to run.

(2) if break down (in Fig. 2 k2 point failure) between bus bar side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay (the switch motion quenching time of hiding is as 160MS) and is first failure to actuate, after the switch tripping of circuit both sides, fault point still exists, the differential difference stream that still has of differential and between-failures does not return on a large scale, differentially among a small circle still to be failure to actuate, be judged as bus bar side dead-zone fault, other elements of bus protection action tripping bus, through the isolated fault of predetermined time delay tripping between-failures bus bar side disconnecting link after bus tripping, other bus bar elements use bus reclose sequence to close non-faulting interval circuit breaker, bus continues to run.

(3) if break down (in Fig. 2 k3 point failure) between bus bar side CT to bus; differential action on a large scale; differential action among a small circle; all intervals are differential is all failure to actuate; judge really as busbar fault; route protection is failure to actuate, and bus protection tripping bus connects all elements and jumping circuit offside circuit breaker far away.

(4) if break down (in Fig. 2 k4 point failure) between bus and II bus bar side CT, differential action on a large scale, differentially among a small circle to be failure to actuate, mother interval differential action, judge really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, II is female littlely differentially makes tripping II bus, and I bus normally runs.

(5) if break down (in Fig. 2 k5 point failure) between bus and I bus bar side CT, differential action on a large scale, differentially among a small circle to be failure to actuate, mother interval differential action, judge really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, I is female littlely differentially makes tripping I bus, and II bus normally runs.

(6) (in Fig. 2 k6 point failure) is broken down between circuit transformer station AL2 line side CT and circuit transformer station BL2 line side CT; differential, differential and all intervals are differential is all failure to actuate, route protection action tripping circuit both sides switch among a small circle on a large scale.

3, bus protection CT arranges and improves

GIS is the abbreviation of gas-insulating and fully-enclosed combined electrical apparatus, it transforming plant primary equipment as the components and parts such as circuit breaker, isolating switch, current transformer, bus link together, be sealed in the metal shell of a ground connection, the insulating gas being filled with the SF6 of certain pressure intensity in shell with ensure alternate, and fracture between reliable insulation.

According to actual GIS air chamber structure, if bus bar side CT is arranged near Z1 air chamber place in Z0 air chamber, as shown in Fig. 3 outlet 1.Judge through this method, when being only bus bar side dead-zone fault (as k1), Z1 air chamber no problem, pulls open between-failures bus disconnecting link and gets final product isolated fault, recovers bussed supply.But Z0 air chamber faulty insulator punctures, whole air chamber can be caused to insulate and to reduce, cause the fault of bus bar side CT own, cause each differential judged result mistake.

If bus bar side CT is arranged in Z1 air chamber near Z0 air chamber place; judge through this method; when being only bus bar side dead-zone fault; if only break down (as k2) between bus bar side CT and Z1 air chamber wall; other part fault-free of Z1 air chamber, pulling open after between-failures bus disconnecting link can temporarily isolated fault, but whole air chamber can cause integral insulation to reduce because of a point failure; develop into busbar fault, tripping bus is connected all elements by bus protection.The probability that in air chamber, local fault causes whole air chamber fault is very large, if be only judged to bus bar side dead-zone fault and without busbar fault, then and Z1 air chamber no problem.

Integrated comparative, suggestion bus bar side CT is installed near Z0 air chamber place in Z1 air chamber, or installs bus bar side CT additional separately between Z1 and Z0 air chamber.

4, analysis of cases

For 220kVGIS equipment, occur as shown in Figure 4 position failure time, according to above-mentioned GIS fault accurate isolate bus protection new principle, can realize fault precise positioning and isolation rapidly, the fast quick-recovery of non-faulting part normally runs.

1) A point failure, control procedure:

(1) utilize formula (1)-(5) to calculate the differential current of three scopes, draw differential action on a large scale, to be differentially among a small circle failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate.

(2), after the differential action of interval, bus protection time delay 160ms starts, and avoids the circuit both sides switch motion time.

(3) L1 circuit both sides circuit breaker tripping, as shown in Figure 5, fault point A is isolated, and is judged as fault between circuit breaker and line side CT.On a large scale differential, among a small circle the differential indifference stream in differential and all intervals return, bus protection is failure to actuate, other intervals of bus continue run.

2) B point failure, control procedure:

(1) utilize formula (1)-(5) to calculate the differential current of three scopes, draw differential action on a large scale, to be differentially among a small circle failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate.

(2), after the differential action of interval, bus protection time delay 160ms starts, and avoids the circuit both sides switch motion time.

(3), after the circuit breaker tripping of both sides, L1 interval, as shown in Figure 5, fault point B still exists.Differential and L1 interval is differential on a large scale has difference stream not return, and be differentially among a small circle failure to actuate, bus protection is action after time delay, other elements of tripping I bus.Be judged as fault between circuit breaker and bus bar side CT.

(4) after fault location, automatic/hand pulls open between-failures bus bar side disconnecting link D2 isolated fault, and other bus bar elements use bus reclosing automatic/hand to close circuit breaker, and bus continues to run.

3) C point breaks down, control procedure:

(1) utilize formula (1)-(5) to calculate the differential current of three scopes, draw differential action on a large scale, among a small circle differential action, all intervals are differential is all failure to actuate.

(2) be judged as breaking down between bus bar side CT to bus.Start bus protection tripping I bus and connect all elements, route protection is failure to actuate.

In sum, this fault location and regulation and control scheme flow process are as shown in Figure 5.

Compared with traditional protection philosophy, program energy accurately failure judgement position, excises isolated fault fast; when preventing monospace internal fault, bus protection is by equal for all connection elements tripping; ensure that the selectivity of bus protection action, reduction accident scope, improves system run all right.

By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (9)

1. realize GIS fault precisely to excise and the bus protection algorithm of automatic recovery of power supply, it is characterized in that, comprise the following steps:

(1) for double-bus or two mother partition main electrical scheme, to suppose on two buses that each linkage unit is that to flow out sense of current from bus be positive direction; Calculate bus differential current, bus differential current and interval differential current among a small circle on a large scale respectively, according to bus differential current, bus differential current and the interval differential current among a small circle on a large scale calculated, judge the whether action of corresponding ratio element;

(2) according to the whether action of large poor ratio element, bus external area error and bus troubles inside the sample space is distinguished; When large poor ratio element movement, by little poor ratio element, whether action determines which section bus is fault occur in; Whether action determines between-failures to clearance ratio difference element;

(3) according to the action situation of large poor ratio element, little poor ratio element and clearance ratio difference element, failure judgement type also makes response to fault;

In described step (3); if break down between bus bar side CT to bus; differential action on a large scale; differential action among a small circle; all intervals are differential is all failure to actuate; judge that route protection is failure to actuate really as busbar fault, bus protection tripping bus connects all elements and jumping circuit offside circuit breaker far away.

2. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, it is characterized in that, in described step (1), differential current calculates scope to bus is on a large scale all septal line trackside CT; Bus among a small circle differential current calculating scope is all interval bus bar side CT; It is between each interval bus bar side CT and line side CT that interval differential current calculates scope.

3. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, it is characterized in that, the computational methods of described step (1) median generatrix differential current are on a large scale:

$I_{cd}=|{\stackrel{\·}{I}}_{1L}+{\stackrel{\·}{I}}_{2L}+...+{\stackrel{\·}{I}}_{nL}|;$

In formula, represent each branch line trackside CT current phasor.

4. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, it is characterized in that, the computational methods of described step (1) median generatrix differential current are among a small circle:

(1) I female little spill current: $I_{cd1}=|{\stackrel{\·}{I}}_{1B}{S}_{11}+{\stackrel{\·}{I}}_{2B}{S}_{12}+...+{\stackrel{\·}{I}}_{nB}{S}_{1n}+{\stackrel{\·}{I}}_{ML1}{S}_{ML}|;$

(2) II female little spill currents: $I_{cd2}=|{\stackrel{\·}{I}}_{1B}{S}_{21}+{\stackrel{\·}{I}}_{2B}{S}_{22}+...+{\stackrel{\·}{I}}_{nB}{S}_{2n}+{\stackrel{\·}{I}}_{ML2}{S}_{ML}|;$

In formula, represent each branch road bus bar side CT current phasor; represent the female side of mother I, II female side CT current phasor respectively; S ₁₁, S ₁₂..., S _1nrepresent the female disconnecting link position of each branch road I; S ₂₁, S ₂₂..., S _2nrepresent the female disconnecting link position of each branch road II; S _mLrepresent bus paired running state.

5. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, it is characterized in that, in described step (1), the computational methods of interval differential current are:

(1) branch road interval differential current:

$I_{cdi}=|{\stackrel{\·}{I}}_{iB}+{\stackrel{\·}{I}}_{iL}|$

Wherein, i=1,2 ... n; be respectively i-th interval bus bar side and line side CT secondary current vector; I _cdibe i-th branch road interval differential current;

(2) mother interval differential current:

$I_{cdML}=|{\stackrel{\·}{I}}_{ML1}+{\stackrel{\·}{I}}_{ML2}|;$

Wherein, be respectively mother I bus bar side and II bus bar side CT secondary current vector; I _cdMLfor mother interval differential current.

6. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, and it is characterized in that, the concrete grammar of described step (3) is:

(1) if break down between line side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay and is first failure to actuate, after the switch tripping of circuit both sides, fault point isolate, on a large scale differential, among a small circle the differential equal indifference stream in differential and all intervals return, be judged as line side dead-zone fault, bus protection is failure to actuate, and other elements of bus continue to run;

(2) if break down between bus bar side CT and switch, differential action on a large scale, differentially among a small circle to be failure to actuate, between-failures differential action, non-faulting interval is differential is failure to actuate, this interval switch of interval differential protection tripping is jumping circuit offside switch far away also, bus protection adds little time delay and is first failure to actuate, after the switch tripping of circuit both sides, fault point still exists, the differential difference stream that still has of differential and between-failures does not return on a large scale, differentially among a small circle still to be failure to actuate, be judged as bus bar side dead-zone fault, other elements of bus protection action tripping bus, through the isolated fault of predetermined time delay tripping between-failures bus bar side disconnecting link after bus tripping, other bus bar elements use bus reclose sequence to close non-faulting interval circuit breaker, bus continues to run.

7. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, and it is characterized in that, the concrete grammar of described step (3) is:

If break down between bus and II bus bar side CT, on a large scale differential action, to be differentially among a small circle failure to actuate, mother interval differential action, judges really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, II is female littlely differentially makes tripping II bus, and I bus normally runs;

If break down between bus and I bus bar side CT, on a large scale differential action, to be differentially among a small circle failure to actuate, mother interval differential action, judges really as mother fault, the differential tripping bus connection switch in interval, after bus connection switch tripping, I is female littlely differentially makes tripping I bus, and II bus normally runs.

8. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1, and it is characterized in that, the concrete grammar of described step (3) is:

If break down between the L2 line side CT of the L2 line side CT of circuit transformer station A and circuit transformer station B, differential, differential and all intervals are differential is all failure to actuate, route protection action tripping circuit both sides switch among a small circle on a large scale.

9. a kind of GIS of realization fault is precisely excised and the bus protection algorithm of automatic recovery of power supply as claimed in claim 1; it is characterized in that; bus bar side CT is installed near circuit breaker air chamber place in 1 disconnecting link air chamber, or installs bus bar side CT additional separately between 1 disconnecting link air chamber and circuit breaker air chamber.