CN103579999B - Multisection type self adaptation high sampling rate transformer sampling value differential protection method - Google Patents

Abstract

The invention discloses a kind of multisection type self adaptation high sampling rate transformer sampling value differential protection method, comprise the following steps: that the three-phase current of side each to transformer carries out two-forty sampling；The three-phase current sampled value of side each to transformer carries out some difference algorithms and compensates current amplitude；The sampling value difference electric current of calculating transformer and sampled value stalling current；Carry out the logic discrimination of sampling value differential protection quick-action section；Carry out the logic discrimination of sensitive section of sampling value differential protection；Carry out the differentiation of the total logic of sampling value difference.The transformer sampling value differential protection method that the present invention provides; solve the problem that action fuzzy region is big, sensitivity is low that existing sampling value differential protection method exists; on the premise of ensureing selectivity, reliability, make rapidity and sensitivity be met simultaneously, have a good application prospect.

Description

Multisection type self adaptation high sampling rate transformer sampling value differential protection method

Technical field

The present invention relates to a kind of multisection type self adaptation high sampling rate being applicable to microcomputer protecting device Transformer sampling value differential protection method, belongs to the technical field of relay protection of power system.

Background technology

Early 1990s, for the research of the microcomputer protective relay in power system, pass In the computer-based transformer protection of system, conventional phasor differential protection is widely used, and has Ripe operating experience, but exist at aspects such as the anti-excitation surge current of transformer and CT are saturated Some defects, for this kind of phenomenon, in recent years it has been proposed that the concept of sampling value differential protection. The sampling value differential protection that we are usually said, be gathered in the moment each to Microcomputer Protection from Scattered sampled value carries out differential differentiation, but, owing to waveform exists zero crossing and other problems, Differentiation result only according to an instance sample value can not be confirmed whether faulty, it is impossible to makes jumping The decision of lock, needs to be carried out continuously R differentiation, if had S time and above point meets differential Operation condition, then be determined as internal fault.Compared with transformer phasor differential protection, transformer Sampling value differential protection has advantages such as strong, the quick action of anti-interference data capability, but by There is the shortcomings such as action fuzzy region is big, sensitivity is low so that sampling value differential protection can not in it Enough depart from phasor differential protection independent operating, be intended only as of phasor differential protection useful Supplementing, the effect played is very limited, thus affects its popularization and application.

Summary of the invention

The technical problem to be solved in the present invention is the motion blur of traditional sampling value differential protection The problems such as Qu great, sensitivity are low, supplementing only as phasor differential protection, limited use, The problem being unfavorable for popularization and application.The multisection type self adaptation high sampling rate transformer that the present invention provides Sampling value differential protection method, by quick-action section and the combination of sensitive section, it is possible to eliminate dynamic Make the impact of confusion region, have the advantages that reliability is high, quick-action is good, highly sensitive, for becoming Depressor provides perfect differential protection scheme, has a good application prospect.

In order to solve above-mentioned technical problem, the technical solution adopted in the present invention is:

A kind of multisection type self adaptation high sampling rate transformer sampling value differential protection method, its feature It is: comprise the following steps,

Step (1), the three-phase current of side each to transformer carries out two-forty sampling；

Step (2), the current sample to transformer each side three-phase that step (1) sampling obtains Value carries out difference algorithm, and the amplitude of three-phase current after difference algorithm is carried out differential compensation；

Step (3), adopts according to the electric current of Transformer Winding connection type side each to transformer three-phase Sample value carries out phasing and amplitude rectification, and according to the current sampling data of three-phase after the correction of each side Calculate difference current and the stalling current of sampled value of three-phase sampled value；

Step (4), the difference current of the three-phase sampled value calculated according to step (3) and sampling The stalling current of value, to sampling value differential protection quick-action section, whether action carries out logic discrimination, will Logic discrimination result sends step (6) to；

Step (5), the difference current of the three-phase sampled value calculated according to step (3) and sampling The stalling current of value, to sensitive section of sampling value differential protection, whether action carries out logic discrimination, will Logic discrimination result sends step (6) to；

Step (6), according to the logic of the sampling value differential protection quick-action section that step (4) transmits The logic discrimination result of sensitive section of the sampling value differential protection that differentiation result and step (5) transmit, To total logic of sampling value differential protection, whether action carries out logic discrimination, if sampling value difference is protected The quick-action section protected and sensitive section have any one action or both actions, then sampling value difference Protection act trips；Otherwise sampling value differential protection is failure to actuate.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: the three-phase current of described step (1) side each to transformer carries out two-forty sampling The sampling number N of each power frequency period is not less than 40 points.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: in described step (4), calculate sampled value differential of three-phase according to step (3) Electric current and the stalling current of sampled value, to sampling value differential protection quick-action section, whether action is patrolled It is as follows volume to sentence method for distinguishing,

The discrimination formula (1) of the sampling value differential protection quick-action section according to single sampled point,

i_d≥i_dsetAnd i_d≥K_seti_r (1)

Wherein i_dIt is the sampling value difference electric current that calculates of step (3), i_rIt is that step (3) calculates Sampled value stalling current, i_dsetFor threshold definite value, K_setFor slope definite value, when sampling value difference When dynamic protection quick-action section puts into always, each sampled point differentiates respectively according to three-phase, if The data of certain sampled point meet the condition of formula (1), then this sampled point meets sampling value difference Dynamic protection quick-action section operating criterion, and in the data window of continuous R point, if having S point and more than Meet operating criterion, then the action of sampling value differential protection quick-action section.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: be described when sampling value differential protection quick-action section puts into always, R, S, i_dsetAnd K_set Four parameters all use fixed value, are according to when sky fills transformer and external area error CT is saturated The reliable not malfunction of sampling value differential protection quick-action section is chosen, and keeps not in protection running Become.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: in described step (5), according to the difference current of the sampled value that step (3) calculates With the stalling current of sampled value, to sensitive section of sampling value differential protection, whether action carries out logic sentences Method for distinguishing is as follows,

The discrimination formula (2) of sensitive section of the sampling value differential protection according to single sampled point,

i_d≥i_dsetAnd i_d≥K_seti_r (2)

Wherein i_dIt is the sampling value difference electric current that calculates of step (3), i_rIt is that step (3) calculates Sampled value stalling current, i_dsetFor threshold definite value, K_setFor slope definite value, when sampling value difference When sensitive section of dynamic protection puts into always, each sampled point differentiates respectively according to three-phase, if The data of certain sampled point meet the condition of formula (2), then this sampled point meets sampling value difference Sensitive section of operating criterion of dynamic protection, and in the data window of continuous R point, if having S point and more than Meet operating criterion, then sensitive section of action of sampling value differential protection.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: be described when sensitive section of sampling value differential protection puts into always, R, K_setTwo parameters Use fixed value, i_dset, two parameters of S use auto-adaptive parameters, wherein parameter R is fixing takes The sampling number N of one power frequency cycle, parameter K_setSample according to when external area error CT is saturated The reliable not malfunction of sensitive section of value differential protection is chosen, and keeps constant in protection running, And auto-adaptive parameter i_dset, S be according to second harmonic in each phase difference current in running Dynamically adjust with triple-frequency harmonics total content, i_dsetExcursion is at i_dset1To i_dset2Between, i_dset1Set according to the reliable not malfunction of sensitive section of sampling value differential protection time properly functioning, i_dset2 Reliable according to sensitive section of the sampling value differential protection when sky fills transformer and external area error CT is saturated Not malfunction sets；S excursion is S₁To S₃, S₁According to sampling value difference time properly functioning Sensitive section of reliable not malfunction is protected to set, S₃Transformer and external area error CT is filled according at sky Time saturated, the reliable not malfunction of sensitive section of sampling value differential protection sets.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: described auto-adaptive parameter i_dsetEstablishing method as follows,

1) first-harmonic, second harmonic and three in difference current are calculated by full-wave fourier algorithm Subharmonic virtual value, obtains second harmonic and triple-frequency harmonics in difference current according to formula (3) Total content K_harm,

$K_{harm}=\frac{\sqrt{I_2^2+I_3^2}}{I_1}---\left(3\right)$

Wherein I₁、I₂、I₃It is respectively first-harmonic, second harmonic and triple-frequency harmonics in difference current Virtual value；

2) harmonic wave weight coefficient M is calculated according to formula (4),

$M=\left\{\begin{array}{cc}0,& K_{harm}<K_{harm1}\\ K_{m1},& K_{harm1}\&le;K_{harm}<K_{harm2}\\ K_{m2},& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(4\right)$

Wherein K_m1、K_m2It is respectively weight coefficient constant 1, weight coefficient constant 2, and meets 0 ＜ K_m1＜ K_m2Relation；K_harm1、K_harm2It is respectively harmonic wave definite value 1, harmonic wave definite value 2, Meet 0 ＜ K_harm1＜ K_harm2Relation；

3) threshold definite value i is calculated according to formula (5)_dset,

i_dset=(1+M) i_dset1 (5)

Wherein M is harmonic wave weight coefficient, i_dset1By sampling value differential protection spirit time properly functioning Quick section of reliable not malfunction sets.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: the establishing method of the auto-adaptive parameter S used by described step (5) is as follows, according to Formula (6) calculates S setting value,

$S=\left\{\begin{array}{cc}{S}_1,& K_{harm}<K_{harm1}\\ S_2,& K_{harm1}\&le;K_{harm}<K_{harm2}\\ S_3,& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(6\right)$

Wherein S₁、S₂、S₃For the different values of S, meet N > S₃≥S₂>S₁Pass System, N is the sampling number of each power frequency period, S₁By sampling value differential protection time properly functioning Sensitive section of reliable not malfunction sets, S₂、S₃Set by not malfunction when dropping normal transformer Fixed；K_harm、K_harm1、K_harm2Implication identical with formula (3) and formula (4).

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: slope definite value K used by described step (5)_setBetween 0.4～0.6 scope.

Aforesaid multisection type self adaptation high sampling rate transformer sampling value differential protection method, it is special Levy and be: the total logic to sampling value differential protection in described step (6) whether enter by action Row logic discrimination, comprises the following steps,

1) the logic discrimination result of the sampling value differential protection quick-action section that step (4) is transmitted and The logic discrimination result input of sensitive section of the sampling value differential protection that step (5) transmits or door；

2) record or the quick-action section of the output result of door, even sampling value differential protection and sensitive Section has any one action or both actions, then sampling value differential protection action tripping operation；No Then sampling value differential protection is failure to actuate.

The invention has the beneficial effects as follows: the multisection type self adaptation high sampling rate transformation that the present invention proposes Device sampling value differential protection uses high-speed sampling technology, it is possible to effectively reduces action fuzzy region, disappears Except the sampling initial time impact on protection act behavior；Use auto-adaptive parameter technology, it is possible to Automatically adjust definite value parameter according to the situation that excitation surge current and CT are saturated, reliably do not miss in guarantee Sensitivity is improve on the premise of Dong；Use quick-action section and the sensitive section of mode combined, make to adopt The selectivity of sample value differential protection, reliability, sensitivity, rapidity are met simultaneously.This The transformer sampling value differential protection technical scheme that invention proposes can be as the main guarantor of transformer Protect scheme, have a good application prospect.

Accompanying drawing explanation

Fig. 1 is the multisection type self adaptation high sampling rate transformer sampling value differential protection of the present invention The flow chart of method.

Fig. 2 is the present invention total logic logic whether action differentiates to sampling value differential protection Figure.

Detailed description of the invention

Below in conjunction with Figure of description, the present invention is further illustrated.

The transformer sampling value differential protection that the present invention proposes includes two sections, and one section is quick-action section, Using preset parameter, one section is sensitive section, uses auto-adaptive parameter, and two sections is all according to split-phase Carrying out logic discrimination, total Trip Logic takes the mode of logic sum gate, if i.e. quick-action section and Sensitive section has any one action or both actions, then sampling value differential protection action tripping operation； Otherwise sampling value differential protection is failure to actuate, and its particular flow sheet is as shown in Figure 1, it is achieved step is such as Under:

The first step, the three-phase current of side each to transformer carries out two-forty sampling, each power frequency week The sampling number N of phase is not less than 40 points；

Second step, is carried out the current sampling data of transformer each side three-phase that first step sampling obtains Difference algorithm, and the amplitude of three-phase current after difference algorithm is carried out differential compensation；

3rd step, according to the current sample of Transformer Winding connection type side each to transformer three-phase Value carries out phasing and amplitude rectification, and according to the current sampling data meter of three-phase after the correction of each side Calculate difference current and the stalling current of sampled value of three-phase sampled value；

4th step, the difference current of three-phase sampled value calculated according to the 3rd step and the system of sampled value Streaming current, to sampling value differential protection quick-action section, whether action carries out logic discrimination, logic is sentenced Other result sends the 6th step to, and to sampling value differential protection quick-action section, whether action is patrolled here It is as follows volume to sentence method for distinguishing,

The discrimination formula (1) of the sampling value differential protection quick-action section according to single sampled point,

i_d≥i_dsetAnd i_d≥K_seti_r (1)

Wherein i_dIt is the sampling value difference electric current of the 3rd step calculating, i_rIt it is the sampling of the 3rd step calculating Value stalling current, i_dsetFor threshold definite value, K_setFor slope definite value, when sampling value differential protection speed When dynamic section puts into always, each sampled point differentiates respectively according to three-phase, if certain sampling The data of point meet the condition of formula (1), then this sampled point meets sampling value differential protection speed Dynamic section operating criterion, in the data window of continuous R point, if having S point and meeting above Operating criterion, the then action of sampling value differential protection quick-action section, R, S, i_dsetAnd K_setFour parameters All use fixed value, be according to value difference of sampling when sky fills transformer and external area error CT is saturated The dynamic reliable not malfunction of protection quick-action section is chosen, and keeps constant in protection running.

5th step, the difference current of three-phase sampled value calculated according to the 3rd step and the system of sampled value Streaming current, to sensitive section of sampling value differential protection, whether action carries out logic discrimination, logic is sentenced Other result sends the 6th step to, and to sensitive section of sampling value differential protection, whether action is patrolled here It is as follows, according to the differentiation of sensitive section of the sampling value differential protection of single sampled point volume to sentence method for distinguishing Formula (2),

i_d≥i_dsetAnd i_d≥K_seti_r (2)

Wherein i_dIt is the sampling value difference electric current of the 3rd step calculating, i_rIt it is the sampled value system of the 3rd step calculating Streaming current, i_dsetFor threshold definite value, K_setFor slope definite value, when sampling value differential protection is sensitive When Duan Yizhi puts into, each sampled point differentiates respectively according to three-phase, if certain sampled point Data meet the condition of formula (2), then to meet sampling value differential protection sensitive for this sampled point Section operating criterion, and in the data window of continuous R point, if having S point and meeting action above and sentence According to, then sensitive section of action of sampling value differential protection.When sampling value differential protection sensitive section is delivered directly Fashionable, R, K_setTwo parameters use fixed value, i_dset, two parameters of S use self adaptations ginseng Number, wherein parameter R fixes the sampling number N taking a power frequency cycle, parameter K_setAccording to When external area error CT is saturated, the reliable not malfunction of sensitive section of sampling value differential protection is chosen, and is protecting Keep constant during shipping sth. under guard row, and auto-adaptive parameter i_dset, S be basis in running In each difference stream, second harmonic and triple-frequency harmonics total content dynamically adjust, i_dsetExcursion For i_dset1To i_dset2Between, i_dset1Reliable according to sensitive section of sampling value differential protection time properly functioning Not malfunction sets, i_dset2According to the sampled value when sky fills transformer and external area error CT is saturated The reliable not malfunction of sensitive section of differential protection sets；S excursion is S₁To S₃, S₁According to just When often running, the reliable not malfunction of sensitive section of sampling value differential protection sets, S₃Change is filled according at sky When depressor and external area error CT are saturated, the reliable not malfunction of sensitive section of sampling value differential protection sets, Described auto-adaptive parameter i_dsetEstablishing method as follows,

1) first-harmonic, second harmonic and three in difference current are calculated by full-wave fourier algorithm Subharmonic virtual value, obtains second harmonic and triple-frequency harmonics in difference current according to formula (3) Total content K_harm,

$K_{harm}=\frac{\sqrt{I_2^2+I_3^2}}{I_1}---\left(3\right)$

Wherein I₁、I₂、I₃It is respectively first-harmonic, second harmonic and triple-frequency harmonics in difference current Virtual value；

2) harmonic wave weight coefficient M is calculated according to formula (4),

$M=\left\{\begin{array}{cc}0,& K_{harm}<K_{harm1}\\ K_{m1},& K_{harm1}\&le;K_{harm}<K_{harm2}\\ K_{m2},& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(4\right)$

Wherein K_m1、K_m2It is respectively weight coefficient constant 1, weight coefficient constant 2, and meets 0<K_m1<K_m2Relation；K_harm1、K_harm2It is respectively harmonic wave definite value 1, harmonic wave definite value 2, Meet 0 < K_harm1<K_harm2Relation；

3) threshold definite value i is calculated according to formula (5)_dset,

i_dset=(1+M) i_dset1 (5)

Wherein M is harmonic wave weight coefficient, i_dset1By sampling value differential protection spirit time properly functioning Quick section of reliable not malfunction sets, and the most all can dynamically be adjusted threshold fixed Value i_dset, then carry out logic discrimination, it is determined whether meet sensitive section of sampling value differential protection and move The condition made；

The establishing method of described auto-adaptive parameter S is as follows, calculates S according to formula (6) and sets Value,

$S=\left\{\begin{array}{cc}{S}_1,& K_{harm}<K_{harm1}\\ S_2,& K_{harm1}\&le;K_{harm}<K_{harm2}\\ S_3,& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(6\right)$

Wherein S₁、S₂、S₃For the different values of S, meet N > S₃≥S₂>S₁Pass System, N is the sampling number of each power frequency period, S₁By sampling value differential protection time properly functioning Sensitive section of reliable not malfunction sets, S₂、S₃Set by not malfunction when dropping normal transformer Fixed；K_harm、K_harm1、K_harm2Implication identical with formula (3) and formula (4)；

Described slope definite value K_setBetween 0.4～0.6 scope, it is used for escaping external area error not The impact of balanced balanced current；

6th step, according to the logic discrimination knot of the sampling value differential protection quick-action section that the 4th step transmits The logic discrimination result of sensitive section of the sampling value differential protection that fruit and the 5th step transmit, to sampled value Whether action carries out logic discrimination to total logic of differential protection, as in figure 2 it is shown, sampling value difference Total logic of protection logic chart whether action differentiates, specifically includes following steps,

1) the logic discrimination result and the of the sampling value differential protection quick-action section that the 4th step is transmitted The logic discrimination result of sensitive section of the sampling value differential protection that five steps transmit inputs or door respectively, its In the logic discrimination result of sampling value differential protection quick-action section of each phase and sampling value difference protect Protect the logic discrimination result of sensitive section connect one or, i.e. the sampling value differential protection of A phase speed The differentiation result of dynamic section and sensitive section of sampling value differential protection connects or door G1, the sampling of B phase The differentiation result of value differential protection quick-action section and sensitive section of sampling value differential protection connects or door G2, The sampling value differential protection quick-action section of C phase and the differentiation result of sensitive section of sampling value differential protection Connect or door G3；

2) record or the quick-action section of the output result of door, even sampling value differential protection and sensitive Section has any one action or both actions, then sampling value differential protection action tripping operation；No Then sampling value differential protection is failure to actuate, and this process is passed through or door G4 realizes, or door G4 Input is connection or the output of door G1, G2, G3 that A, B, C phase differentiates result, or The output of door G4, i.e. sampling value differential protection action judged result.

Owing to the action situation of sampling value differential protection is within the specific limits by sampling initial time Impact, there is action fuzzy region, the sampling number of each power frequency period is the most, at the beginning of being sampled Begin the moment impact the least, action fuzzy region is the least, the present invention by improve sample rate with And the Rational choice to definite value parameter, it is possible to effectively reducing action fuzzy region, it is differential fixed to meet Value error less than 5% requirement, with every power frequency cycle sampling number be 72 for embodiment by The method provided according to the present invention is analyzed:

For sampling value differential protection quick-action section, using preset parameter, the value of each parameter is as follows: R=R₀, S=S₀、i_dset=i_dset0、K_set=K_set0, wherein R₀=60, S₀=51, i_dset0 Taking 1.0～1.5Ie, Ie is transformer secondary rated current, K_set0Take 0.4～0.6, value difference of sampling Dynamic protection quick-action section can the reliable not malfunction when sky fills transformer and external area error CT is saturated, For the fault that transformer district internal ratio is more serious, differential protection quick-action section can be within 20ms Send out tripping operation order；

For sensitive section of sampling value differential protection, the value of preset parameter is as follows: R₁=72, S₁=60, S₂=62, S₃=64, i_dset1Take 0.2～0.4Ie, K_set1Take 0.4～0.6, this In R=R₁, S=S₁Or S=S₂Or S=S₃、K_set=K_set1, i_dsetEmploying self adaptation is joined Number, at i_dset1～i_dset2In the range of, according to said method, sensitive section of sampling value differential protection Auto-adaptive parameter i_dsetCalculating according to formula (5), the computational methods of harmonic wave weight coefficient M are:

$M=\left\{\begin{array}{cc}0,& K_{harm}<0.08\\ 1.5,& 0.08\&le;K_{harm}<0.15\\ 3,& K_{harm}\&GreaterEqual;0.15\end{array}\right.$

Wherein K_m1=1.5, K_m2=3, meet 0 < K_m1<K_m2；K_harm1=0.08, K_harm2=0.15, Meet 0 < K_harm1<K_harm2, according to formula (6), S value is as follows:

$S=\left\{\begin{array}{cc}60,& K_{harm}<0.08\\ 62,& 0.08\&le;K_{harm}<0.15\\ 64,& K_{harm}\&GreaterEqual;0.15\end{array}\right.$

For power transformer interior fault, based on first-harmonic content in difference current, second harmonic and Triple-frequency harmonics content is less, i_dsetAutomatically definite value i is removed the limit_dset1, S removes the limit definite value S automatically₁, Sampling value differential protection keeps higher sensitivity；Transformer is filled for sky, secondary in difference current Harmonic content is relatively big, and triple-frequency harmonics takes second place, i_dsetAutomatically raise with S, sampling value differential protection Excitation surge current can be escaped；Filling in failure transformer for sky, fault phase harmonic attenuation is very fast, Definite value i_dsetAutomatically reduce according to harmonic attenuation situation with S, sampling value differential protection deferred action； Saturated for external area error CT, second harmonic and triple-frequency harmonics total content are relatively big, parameter i_dsetWith S raises automatically, and sampling value differential protection can resist CT saturated.

The general principle of the present invention, principal character and advantage have more than been shown and described.The industry Skilled person will appreciate that, the present invention is not restricted to the described embodiments, above-described embodiment and The principle that the present invention is simply described described in specification, without departing from spirit and scope of the invention On the premise of, the present invention also has various changes and modifications, and these changes and improvements both fall within to be wanted In seeking the scope of the invention of protection.Claimed scope by appending claims and Its equivalent defines.

Claims (10)

1. multisection type self adaptation high sampling rate transformer sampling value differential protection method, its feature It is: comprise the following steps,

Step (1), the three-phase current of side each to transformer carries out two-forty sampling；

Step (2), the current sample to transformer each side three-phase that step (1) sampling obtains Value carries out difference algorithm, and the amplitude of three-phase current after difference algorithm is carried out differential compensation；

Step (3), adopts according to the electric current of Transformer Winding connection type side each to transformer three-phase Sample value carries out phasing and amplitude rectification, and according to the current sampling data of three-phase after the correction of each side Calculate difference current and the stalling current of sampled value of three-phase sampled value；

Step (4), the difference current of the three-phase sampled value calculated according to step (3) and sampling The stalling current of value, to sampling value differential protection quick-action section, whether action carries out logic discrimination, will Logic discrimination result sends step (6) to；

Step (5), the difference current of the three-phase sampled value calculated according to step (3) and sampling The stalling current of value, to sensitive section of sampling value differential protection, whether action carries out logic discrimination, will Logic discrimination result sends step (6) to；

Step (6), according to the logic of the sampling value differential protection quick-action section that step (4) transmits The logic discrimination result of sensitive section of the sampling value differential protection that differentiation result and step (5) transmit, To total logic of sampling value differential protection, whether action carries out logic discrimination, if sampling value difference is protected The quick-action section protected and sensitive section have any one action or both actions, then sampling value difference Protection act trips；Otherwise sampling value differential protection is failure to actuate.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 1 Differential protecting method, it is characterised in that: the three-phase electricity of described step (1) side each to transformer Stream carries out the sampling number N of each power frequency period of two-forty sampling not less than 40 points.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 1 Differential protecting method, it is characterised in that: in described step (4), calculate according to step (3) The difference current of the sampled value of three-phase and the stalling current of sampled value, to sampling value differential protection speed The method that the whether action of dynamic section carries out logic discrimination is as follows,

The discrimination formula (1) of the sampling value differential protection quick-action section according to single sampled point,

i_d≥i_dsetAnd i_d≥K_seti_r (1)

Wherein i_dIt is the sampling value difference electric current that calculates of step (3), i_rIt is that step (3) calculates Sampled value stalling current, i_dsetFor threshold definite value, K_setFor slope definite value, when sampling value difference When dynamic protection quick-action section puts into always, each sampled point differentiates respectively according to three-phase, if The data of certain sampled point meet the condition of formula (1), then this sampled point meets sampling value difference Dynamic protection quick-action section operating criterion, in the data window of continuous R point, if having S to put and More than meet operating criterion, the then action of sampling value differential protection quick-action section.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 3 Differential protecting method, it is characterised in that: described put into when sampling value differential protection quick-action section always Time, R, S, i_dsetAnd K_setFour parameters all use fixed value, are to fill transformer according at sky Time saturated with external area error CT, the reliable not malfunction of sampling value differential protection quick-action section is chosen, Protection running keeps constant.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 1 Differential protecting method, it is characterised in that: in described step (5), calculate according to step (3) The difference current of sampled value and the stalling current of sampled value, to sensitive section of sampling value differential protection To carry out the method for logic discrimination as follows in action,

The discrimination formula (2) of sensitive section of the sampling value differential protection according to single sampled point,

i_d≥i_dsetAnd i_d≥K_seti_r (2)

Wherein i_dIt is the sampling value difference electric current that calculates of step (3), i_rIt is that step (3) calculates Sampled value stalling current, i_dsetFor threshold definite value, K_setFor slope definite value, work as sampling value difference When protecting sensitive section to put into, each sampled point differentiates respectively according to three-phase always, if certain The data of individual sampled point meet the condition of formula (2), then this sampled point meets sampling value difference Protect sensitive section of operating criterion, continuous R point data window in, if having S put and with On meet operating criterion, then sensitive section of action of sampling value differential protection.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 5 Differential protecting method, it is characterised in that: described put into when sensitive section of sampling value differential protection always Time, R, K_setTwo parameters use preset parameter, i_dset, two parameters of S use self adaptations ginseng Number, wherein parameter R fixes the sampling number N taking a power frequency cycle, parameter K_setAccording to When external area error CT is saturated, the reliable not malfunction of sensitive section of sampling value differential protection is chosen, and is protecting Keep constant during shipping sth. under guard row, and auto-adaptive parameter i_dset, S be basis in running In each phase difference current, second harmonic and triple-frequency harmonics total content dynamically adjust, i_dsetChange Scope is at i_dset1To i_dset2Between, i_dset1According to sensitive section of sampling value differential protection time properly functioning Reliable not malfunction sets, i_dset2Adopt according to when sky fills transformer and external area error CT is saturated The reliable not malfunction of sensitive section of sample value differential protection sets；S excursion is S₁To S₃, S₁Press Set according to the reliable not malfunction of sensitive section of sampling value differential protection time properly functioning, S₃According to Sky fill transformer and external area error CT saturated time the reliable not malfunction of sensitive section of sampling value differential protection Set.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 5 Differential protecting method, it is characterised in that: described auto-adaptive parameter i_dsetEstablishing method as follows,

1) first-harmonic, second harmonic and three in difference current are calculated by full-wave fourier algorithm Subharmonic virtual value, obtains second harmonic and triple-frequency harmonics in difference current according to formula (3) Total content K_harm,

$K_{harm}=\frac{\sqrt{I_2^2+I_3^2}}{I_1}---\left(3\right)$

Wherein I₁、I₂、I₃It is respectively first-harmonic, second harmonic and triple-frequency harmonics in difference current Virtual value；

2) harmonic wave weight coefficient M is calculated according to formula (4),

$M=\left\{\begin{array}{cc}0,& K_{harm}<K_{harm1}\\ K_{m1},& K_{harm1}\&le;K_{harm}<K_{harm2}\\ K_{m2},& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(4\right)$

Wherein K_m1、K_m2It is respectively weight coefficient constant 1, weight coefficient constant 2, and meets 0<K_m1<K_m2Relation；K_harm1、K_harm2It is respectively harmonic wave definite value 1, harmonic wave definite value 2, Meet 0 < K_harm1<K_harm2Relation；

3) threshold definite value i is calculated according to formula (5)_dset,

i_dset=(1+M) i_dset1 (5)

In formula, M is harmonic wave weight coefficient, i_dset1By sampling value differential protection spirit time properly functioning Quick section of reliable not malfunction sets.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 5 Differential protecting method, it is characterised in that: the establishing method of described auto-adaptive parameter S is as follows, root S setting value is calculated according to formula (6),

$S=\left\{\begin{array}{cc}{S}_1,& K_{harm}<K_{harm1}\\ S_2,& K_{harm1}\&le;K_{harm}<K_{harm2}\\ S_3,& K_{harm}\&GreaterEqual;K_{harm2}\end{array}\right.---\left(6\right)$

Wherein S₁、S₂、S₃For the different values of S, meet N ＞ S₃≥S₂＞ S₁Relation, N is the sampling number of each power frequency period, S₁Sensitive by sampling value differential protection time properly functioning The reliable not malfunction of section sets, S₂、S₃Set by not malfunction when dropping normal transformer； K_harm、K_harm1、K_harm2Implication identical with formula (3) and formula (4).

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 5 Differential protecting method, it is characterised in that: described slope definite value K_setBetween 0.4～0.6 scope.

Multisection type self adaptation high sampling rate transformer sampled value the most according to claim 1 Differential protecting method, it is characterised in that: in described step (6) to sampling value differential protection Total logic whether action carries out logic discrimination, comprise the following steps,

1) the logic discrimination result of the sampling value differential protection quick-action section that step (4) is transmitted and The logic discrimination result input of sensitive section of the sampling value differential protection that step (5) transmits or door；

2) record or the quick-action section of the output result of door, even sampling value differential protection and sensitive Section has any one action or both actions, then sampling value differential protection action tripping operation；No Then sampling value differential protection is failure to actuate.