CN104133156B - Hybrid line single-ended traveling wave fault distance measuring method based on fault distance interval - Google Patents

Abstract

The invention discloses a hybrid line single-ended traveling wave fault distance measuring method based on a fault distance interval. A fault distance interval is preliminarily determined based on single-ended power frequency, the focus is on the scope of research of traveling wave, and the law of traveling wave is analyzed in a targeted mode, thereby realizing accurate fault location. The method is high in distance measuring precision, ranging dead zones do not exist for connection point neighborhood faults, and a connection point fault can be correctly identified or a fault section can be correctly distinguished. The method only uses single-ended data, is easy to implement technologically, has high economical efficiency, is convenient for device installation and popularization, and has high practical application value.

Description

A kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance

Technical field

The present invention relates to a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance.

Background technology

Current power transmission circuit is gradually transformed to aerial line-cable series-parallel connection multi-line power transmission mode.It is accurately positioned series-parallel connection circuit Rational reclosing strategy, to mitigating line walking burden, is formulated in trouble point, realizes the fast quick-recovery of power supply significant.

Existing series-parallel connection circuit distance-finding method with both-end mensuration based on, including both-end power frequency is mensuration and both-end traveling wave method.Both-end Power frequency is mensuration be based primarily upon fault after circuit sequence voltage or sequence current amplitude relation carry out trouble point reckoning or search, the method is deposited The problems such as pseudo- root, connection point near fault section error in judgement, and fault section error in judgement will affect reclosing Correct implement, may lead to that delayed recovery is powered or electrical network suffers from secondary pulse；Both-end traveling wave method catches and reaches two ends bus Primary fault traveling wave is found range, and theoretical precision is high, but actually used in too strong to gps synchronised clock dependency, reliability is inclined Low, and dual ended device cost is higher, is unfavorable for the popularization of distance-finding method.

Single-ended mensuration range finding is not restricted by factors such as communication condition, economic condition, administration authorities, relatively both-end method low cost, Reliability is high, it is easy to accomplish；If ensure that the precision of single-ended algorithm, single-ended mensuration than both-end mensuration advantageously.But mesh Front less to single-ended mensuration research.Trace it to its cause, the mensuration available information of single-ended power frequency is not enough, and range measurement is undesirable； Single-ended traveling wave method due in joint line traveling wave the folding of complexity, reflection can occur, wave head is difficult to, and application is restricted.Existing Single Terminal Traveling Wave Fault Location method in some power distribution network joint lines does not analyze the dissemination of traveling wave comprehensively, and practicality is relatively low. Additionally, by intelligent algorithm Judging fault section, calculating fault distance using traveling wave in determination section, need actual event in a large number Barrier data, is difficult to from practical standpoint.It is therefore proposed that a kind of single-ended measurement simultaneously meeting precision and practicality requirement It is the important directions of current research away from method.

Content of the invention

The present invention is in order to solve the above problems it is proposed that a kind of series-parallel connection line one-end traveling wave interval based on fault distance is former Barrier distance-finding method, the method recognizes scope using the fault distance Operations of Interva Constraint traveling wave based on power frequency amount, and lifting single-ended traveling wave is surveyed Away from dependable with function；By pointedly analyzing traveling wave propagation law in focal zone, build fault point positioning method, Section junction point failure criterion and fault section criterion, and guarantee range accuracy is rejected by interference ripple.

To achieve these goals, the present invention adopts the following technical scheme that

A kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance, comprises the following steps:

(1) it is based on circuit distributed parameter model, using the purely resistive of transition resistance, build fault location equation, false first If fault occurs certain point on certain section circuit, fault location equation search zero point is converted to this section of corresponding positioning letter Number solves bare minimum point；

(2) every section of circuit is searched in respective length range with extreme point, comprehensive each section result obtains trouble point and is located Interval, failure judgement point and the relation being connected vertex neighborhood, if be located at neighborhood in, execution step 3)；Beyond neighborhood, then hold Row step 5)；

(3) junction point fault is determined whether by junction point failure criterion: be that in this neighborhood, junction point is fault Point, range finding terminates；Otherwise determine time interval t, by fault section criterion Judging fault section；

(4) determine the polar relationship of each current traveling wave in fault section；Reject interference ripple with reference to series-parallel connection line construction；According to Polar relationship identification through section head end and fault point reflection echo once, through segment ends reflection echo once, note The record corresponding moment；Calculate fault distance, range finding terminates；

(5) fault distance interval is converted to time interval；According to the polar relationship determining in fault section, with reference to series-parallel connection Line construction rejects interference ripple；According to polar relationship identification through section head end and fault point reflection echo once, through section End reflection echo once, the record corresponding moment；Calculate fault distance, range finding terminates.

In described step (1), series-parallel connection circuit is aerial line, the alternatively distributed structure of cable, thus aerial line and cable are certainly So circuit is divided into different sections, what each section of this paper referred to is exactly each built on stilts line segment and each cut cable.

In described step (2), the method in the interval of each section result localization of faults particularly as follows:

1) if the point in only one of which section in all results, remaining is each section junction point, takes this interior position；

2) if there being the point in two sections in all results, remaining is section junction point, takes the section between point in two to connect Connecting point position；

3) if all results are section junction point, take the junction point position repeated.

In described step (3), the criterion connecting point failure is: at junction point during fault, traveling wave (afterwards) two before junction point In section through even reflection polarity constant it may be assumed that

$\left\{\begin{array}{c}\mathrm{sgn}\left[m(t_0+\frac{{2l}_{j-1}}{v_{j-1}})\right]\·\mathrm{sgn}\left[m(t_0+\frac{{4l}_{j-1}}{v_{j-1}})\right]=1\\ \mathrm{sgn}\left[m(t_0+\frac{{2l}_j}{v_j})\right]\·\mathrm{sgn}\left[m(t_0+\frac{{4l}_j}{v_j})\right]=1\end{array}\right.$

Wherein, t₀The primary fault current traveling wave detecting for measurement end, l_j、l_j-1It is respectively jth section and -1 section of circuit of jth Length, v_j、v_j-1It is respectively the traveling wave speed in jth section and -1 section of circuit of jth, m represents and carries out small echo change to electric current line line ripple The Wavelet Modulus Maxima (wmm) in corresponding moment, sgn function stand polarity in bracket after changing.When in formula, two formulas are set up simultaneously, sentence Determining trouble point is t_j.

In described step (3), fault section criterion is: traveling wave is through reflecting between trouble point and junction point once with reflection twice Polar relationship depend on the type of guilty culprit section, polarity is identical, fault generation be described in built on stilts line segment, opposite polarity, Illustrate fault occur in cut cable it may be assumed that

Wherein, t ' is in time interval, according to polar relationship pick out through junction point, fault point reflection ripple once Head reaches the moment of measurement end.

Described step (4) method particularly includes: after determining fault section, according to three electricity of structure determination of series-parallel connection circuit The polar relationship of popular ripple, then in the time interval delimited, detection respectively meets the wave head of polarity condition, according to wave head pair In the moment answered, calculate fault distance.

In described step (4), the moment of echo is the direct conditions calculating fault distance, and this moment is unknown, needs To be detected in respective time interval according to polar relationship.

In described step (4), (5), with reference to the method that series-parallel connection line construction proposes interference ripple it is: from polarity of traveling wave and section From the aspect of length two, wave head to be identified will be likely to result in the wavelet modulus maxima zero setting of the wave head of interference.

The invention has the benefit that

1. belong to one-terminal data distance-finding method, current series-parallel connection circuit distance-finding method is most mensuration for both-end, existing one-terminal data Distance-finding method lacks practicality；The present invention's is single-ended mensuration practical, mensuration with both-end compared with good economy performance, reliability high, It is easy to realize in device；

2. there is not range finding dead band in total track length；For fault at the junction point between aerial line, cable, it is provided that junction point Failure criterion；For junction point near fault, it is provided that fault section criterion；

3. highly versatile, can be used for multistage aerial line-cable series-parallel connection circuit.

Brief description

Fig. 1 is order components schematic diagram in fault section；

Fig. 2 is the catadioptric schematic diagram of fault traveling wave；

Fig. 3 is b type joint line schematic diagram；

Fig. 4 a connects vertex neighborhood fault schematic diagram for section；

Fig. 4 b is section junction point near fault schematic diagram；

Fig. 5 is interference traveling wave schematic diagram.

Specific embodiment:

The invention will be further described with embodiment below in conjunction with the accompanying drawings.

1 fault distance is interval

Series-parallel connection track section parameter is inconsistent, and natural impedance discontinuity point is more, and the dissemination leading to its traveling wave is than single Type line is increasingly complex, relies on single-ended traveling wave cannot complete accurate fault localization.But when known to fault coverage, traveling wave Transmission has specific rule.Therefore, primarily determine that abort situation neighborhood using single-ended power frequency amount, targetedly analysis focuses on The dissemination of single-ended traveling wave in region, is conducive to accurately determining abort situation.

In view of the segmentation feature of joint line parameter, trouble point is primarily determined that using the piecewise method deducing fault section Neighborhood.Meter and cable run distribution capacity are larger, using distributed parameter transmission line model.

Based on circuit distributed parameter model, using the purely resistive of transition resistance, build fault location equation.With single-phase earthing As a example fault, formula (1) gives single type line fault positioning equation.

$\mathrm{im}({\stackrel{\·}{u}}_{f1}+{\stackrel{\·}{u}}_{f2}+{\stackrel{\·}{u}}_{f0}/{\stackrel{\·}{i}}_{f2})=0---\left(1\right)$

In formula:It is respectively fault point sequence voltage,For fault branch negative-sequence current.

Joint line cannot be determined in advance fault section, therefore not directly applying equation (1) fault point.Herein adopt by The mode that section deduces trouble point is processed, and assumes initially that fault occurs on jth section circuit away from section head end x_jThe f point at place, such as Shown in Fig. 1:

Equation (1) search zero point will be converted to and this section of corresponding mapping function will be searched for bare minimum point:

$\min \left|\right|\mathrm{im}({\stackrel{\·}{u}}_{\mathrm{jf}1}+{\stackrel{\·}{u}}_{\mathrm{jf}2}+{\stackrel{\·}{u}}_{\mathrm{jf}0}/{\stackrel{\·}{i}}_{\mathrm{jf}2})\left|\right|---\left(2\right)$

Wherein,

$\left\{\begin{array}{c}{\stackrel{,}{u}}_{\mathrm{jfs}}={\stackrel{,}{u}}_{\mathrm{js}}\mathrm{ch}{\mathrm{\γ}}_{\mathrm{js}}{x}_j-z_{\mathrm{jcs}}{\stackrel{,}{i}}_{\mathrm{js}}\mathrm{sh}{\mathrm{\γ}}_{\mathrm{js}}{x}_j\\ {\stackrel{,}{u}}_{\mathrm{jfs}}={\stackrel{,}{u}}_{(j+1)s}\mathrm{ch}{\mathrm{\γ}}_{\mathrm{js}}(l_j-x_j)+z_{\mathrm{jcs}}{\stackrel{,}{i}}_{(j+1)s}\mathrm{sh}{\mathrm{\γ}}_{\mathrm{js}}(l_j-x_j)\\ {\stackrel{,}{i}}_{\mathrm{jmfs}}=-(\frac{{\stackrel{,}{u}}_{\mathrm{js}}}{z_{\mathrm{jcs}}}\mathrm{sh}{\mathrm{\γ}}_{\mathrm{js}}{x}_j-{\stackrel{,}{i}}_{\mathrm{js}}\mathrm{ch}{\mathrm{\γ}}_{\mathrm{js}}{x}_j)\\ {\stackrel{,}{i}}_{\mathrm{jnfs}}=-[\frac{{\stackrel{,}{u}}_{(j+1)s}}{z_{\mathrm{jcs}}}\mathrm{sh}{\mathrm{\γ}}_{\mathrm{js}}(l_j-x_j)+{\stackrel{,}{i}}_{(j+1)s}\mathrm{ch}{\mathrm{\γ}}_{\mathrm{js}}(l_j-x_j)]\\ {\stackrel{,}{u}}_{(j+1)s}={\stackrel{,}{i}}_{(j+1)s}{z}_{\mathrm{jns}}\\ {\stackrel{,}{i}}_{\mathrm{jfs}}={\stackrel{,}{i}}_{\mathrm{jmfs}}+{\stackrel{,}{i}}_{\mathrm{jnfs}}\end{array}\right.---\left(3\right)$

In formula (2), (3): behalf order components, s=1,2,0, subscript j represents jth section circuit, l_jLong for jth section circuit Degree, z_jcsFor jth section circuit sequence natural impedance, γ_jsFor jth section circuit sequence propagation coefficient,Hypothesis fault point sequence for j section Voltage, It is respectively the sequence electric current that jth section is assumed trouble point by head end and end injection,Hypothesis event for jth section Sequence electric current on barrier branch road, z_jnsFor assuming equivalent peer-to-peer system impedance used during jth segment fault.z_jn1Can be expressed as:

$z_{\mathrm{jn}1}=z_{n1}+\underset{k=j+1}{\overset{n}{\mathrm{\σ}}}{z}_{k1}{l}_k---\left(4\right)$

In formula, z_n1For positive-sequence impedance of opposite side system, z_k1For the positive sequence impedance of kth section circuit unit length, l_kFor kth section line Road length.

For certain section of circuit, mapping function only comprises one variable of fault distance, if the vacation broken down in this section It is set as standing, minimum point in the range of this segment length for the mapping function is trouble point.If assuming to be false, mapping function does not exist Zero crossing, but minima will be reached at nearly failed endpoint, can determine whether the position relationship of this section and true fault section accordingly.

Extreme point to every section of circuit search type (2) in respective length range, comprehensive each section result obtains trouble point Primary Location result, method is:

1) if the point in only one of which section in all results, remaining is each section junction point, takes this interior position；

2) if there being the point in two sections in all results, remaining is section junction point, takes the section between point in two to connect Connecting point position；

3) if all results are section junction point, take the junction point position repeated.

The neighborhood that trouble point is located be can determine by Primary Location result, this is targetedly to know from single-ended traveling wave of realizing Do not provide feasibility.Fault distance interval d is represented by:

D=[d- ε l, d+ ε l] (5)

In formula: d is the Primary Location result based on single-ended power frequency amount, l is total line length, and ε is length percent, ε root Factually border system situation value.

2 trouble points are accurately positioned

Under the premise of fault section gives, the identification of traveling wave is limited in less specific region, such that it is able to poly- Hold traveling wave propagation law in burnt region, realize trouble point and be accurately positioned.

2.1 traveling wave catadioptric analyses

Series-parallel connection circuit as shown in Figure 2, the f point between j section bc is in t_fMoment breaks down.i₀(t)、i₁(t)、i₂(t) point The primary fault current traveling wave that do not detect for measurement end a, through section head end b and fault point reflection echo once, through area Section end c reflection echo once, three is respectively t in the corresponding moment₀、t₁、t₂.Three current traveling waves can be expressed as:

$\left\{\begin{array}{c}{i}_0\left(t\right)=(1+{\mathrm{\ρ}}_a){\mathrm{ri}}_b(t-t_f-{\mathrm{\τ}}_{\mathrm{af}})\\ i_1\left(t\right)={\mathrm{\ρ}}_b{\mathrm{\ρ}}_{f}r(1+{\mathrm{\ρ}}_a)i_b(t-t_f-{\mathrm{\τ}}_{\mathrm{af}}-{2\mathrm{\τ}}_{\mathrm{bf}})\\ i_2\left(t\right)={\mathrm{\ρ}}_c{r}_{f}r(1+{\mathrm{\ρ}}_a)i_f(t-t_f-{\mathrm{\τ}}_{\mathrm{af}}-{2\mathrm{\τ}}_{\mathrm{cf}})\end{array}\right.---\left(6\right)$

In formula: ρ_a、ρ_b、ρ_c、ρ_fIt is respectively current traveling wave at bus a, section junction point b, junction point c, trouble point f Reflection coefficient, r_fFor coefficient of refraction at f for the current traveling wave, r is the coefficient of refraction at current traveling wave each junction point between af Product, τ_af、τ_bf、τ_cfIt is respectively propagation time on circuit af, bf, cf for the current traveling wave, i_b、i_fIt is respectively what trouble point produced Along circuitWithThe fault current traveling wave that direction is propagated.

It can be seen that, i₁(t)、i₂(t) respectively with i₀T the relative polarity of () depends on the polarity of reflection coefficient at section junction point. Series-parallel connection circuit is based on aerial line, the alternate framework of cable, and surge impedance of a line assumes size and is alternately distributed, and leads to current traveling wave to exist At same section two-end-point, reflection coefficient polarity is identical, and is in positive-negative polarity alternate along different sections, thus focusing on interval The polarity of interior specific traveling wave has certain regularity, on this basis, realizes focusing on the accurate calculating of interval internal fault position.

2.2 trouble points are accurately positioned

Using b type joint line as analysis and simulation object, as shown in Figure 3.When fault respectively appears in three sections, Each reflection coefficient and i₀(t)、i₁(t)、i₂T the polarity of () is shown in Table 1.

Table 1 current traveling wave polarity table

Thus, this polar relationship can be utilized, in moment t₁、t₂The time neighborhood t being each located₁、t₂Interior identification i₁(t)、i₂ (t).Fault distance x can be calculated respectively according to identified wave head each self-corresponding moment₁、x₂, the two averagely finally gives trouble point Position x:

$\left\{\begin{array}{c}{x}_1=\underset{k=1}{\overset{j-1}{\mathrm{\σ}}}{l}_k+\frac{(t_1-t_0)v_j}{2}\\ x_2=\underset{k=1}{\overset{j}{\mathrm{\σ}}}{l}_k-\frac{(t_2-t_0)v_j}{2}\\ x=\frac{(x_1+x_2)}{2}\end{array}\right.---\left(7\right)$

Wherein, v_jFor the corresponding traveling wave speed of fault section, time interval t₁、t₂Corresponding with fault distance interval d:

$\left\{\begin{array}{c}{t}_1=[t_0+2(d-\mathrm{\ϵl}])/v_j,t_0+2(d+\mathrm{\ϵl})/v_j]\\ t_2=[t_0+2(l_j-d-\mathrm{\ϵl})/v_j,t_0+2(l_j-d+\mathrm{\ϵl})/v_j]\end{array}\right.---\left(8\right)$

2.3 sections connect vertex neighborhood fault location

When section connects vertex neighborhood fault across two sections, there is fault distinguishing and event at junction point in fault distance interval The problem of barrier section identification, therefore section connect vertex neighborhood fault and have particularity, need analyzing in detail.Fig. 4 (a) and Fig. 4 (b) point Wei not junction point t_jFault and t_jThe situation of near fault.Judge to meet the fault of formula (9) as connecting vertex neighborhood fault:

||d-l_tj||≤εl (9)

In formula: l_tjFor the distance after the velocity of wave normalization of certain junction point to measurement end.

A. fault at junction point

Based on aerial line, the alternate distributed architecture of cable, the polarity phase of traveling wave reflection coefficient at same section two-end-point With, therefore constant through even reflection polarity in same section.This polar relationship can be used as judging whether this trouble point is junction point Criterion:

$\left\{\begin{array}{c}\mathrm{sgn}\left[m(t_0+\frac{{2l}_{j-1}}{v_{j-1}})\right]\·\mathrm{sgn}\left[m(t_0+\frac{{4l}_{j-1}}{v_{j-1}})\right]=1\\ \mathrm{sgn}\left[m(t_0+\frac{{2l}_j}{v_j})\right]\·\mathrm{sgn}\left[m(t_0+\frac{{4l}_j}{v_j})\right]=1\end{array}\right.---\left(10\right)$

In formula: m represents the Wavelet Modulus Maxima that electric current line line ripple is carried out with the corresponding moment in the bracket after wavelet transformation (wmm), sgn function stand polarity.When two formulas are set up simultaneously in formula (10), judge that trouble point is t_j.

B. junction point near fault

During junction point near zone fault, such as shown in Fig. 4 (b), f is true fault point, t_jFor section junction point, f⁰Serve as reasons The trouble point of power frequency amount Primary Location, f ' is f point with regard to t_jPoint of symmetry, i₁(t)、i₂T () is respectively the fault being derived from f and f ' Current traveling wave.

Now temporal interval conversion method is:

$t=(t_0,t_0+\frac{2}{v_f}(\mathrm{\ϵl}+|d-l_{\mathrm{tj}}\left|\right))]---\left(11\right)$

In formula: v_fFor the corresponding velocity of wave of point f place section.

When f ' is located in interval d, because of t_jBoth sides surge impedance of a line is different, i₁(t)、i₂T () is in t_jThe reflection coefficient pole at place Property contrary, the initial polarity of the two is contrary simultaneously, therefore i₁(t)、i₂T () polarity is identical.Now event cannot be judged according to polarity of traveling wave Barrier section.

Analysis i₁(t) and the i in Fig. 4 (b)₃T (), remembers i₃T () is in t_jThe reflection coefficient at place is designated as ρ.If f point is located at frame Ceases to be busy side, then ρ > 0, i₃(t) and i₁T () polarity is identical；If f point is located at cable side, ρ < 0, i₃(t) and i₁(t) opposite polarity. This polar relationship and f, t_jThe relative position of the two is unrelated, provides fault section criterion accordingly:

In formula, t' is in temporal interval t, the i being identified using polar relationship in table one₁(t) or i₂T () reaches measurement The moment at end.

3. algorithm is realized

Such analysis are to carry out under the hypothesis not considering to disturb, in practical situation, the echo meeting of some junction points Occur in time interval to be identified, if its polarity is identical with echo to be identified, constitute interference, may impact range measurement Accuracy.Therefore rejecting interference ripple is the key that context of methods is realized.On the basis of exclusive PCR, preceding method may make up Complete series-parallel connection line fault location algorithm.

3.1 interference ripples are rejected

As shown in figure 5, j intra-segment fault, the current traveling wave that trouble point produces is divided into initially according to initial motion direction The i of positive direction_bInitially reciprocal i_f,.Initial positive direction traveling wave reflects through even in section k (k=1,2 ... j-1), its Polarity keeps constant, reach measurement end for same polarity ripple, (same polarity in herein, reversed polarity are with respect to i₀The polarity of (t) For).Initially reciprocal current traveling wave, section k (k=j+1, j+2 ... n) in through odd reflection after reach measurement end: if k Section is overhead transmission line, and section end points reflection coefficient is to keep constant on the occasion of, polarity of traveling wave, reach measurement end for reversed polarity Ripple；If k section is cable run, section end points reflection coefficient is negative value, through odd reflected traveling wave polarity inversion, reaches measurement end For same polarity ripple.Propagate adjoint decay due to traveling wave to become apparent from section junction point, do not examine when therefore rejecting interference Consider the multiple reflections in certain section, or the reflection process in Multi sectional.

Analyzed according to above, reject interference ripple from the aspect of polarity and line length two, method is as follows:

1) to i₂T interference that () may be subject to only need to consider the section before fault section.If i₂T () is same polarity ripple, will The corresponding moment isThe wmm zero setting of wave head (the corresponding moment in herein is and i₀(t) reach measurement end when The difference carved), afterwards x is calculated with formula (7)₂；If i₂T () is reversed polarity ripple, need not reject interference ripple, directly calculates x₂；

2) if i₁T () is same polarity ripple, will correspond to the moment and beAnd(j ＜ k≤n and Kth section be cable) wave head wmm zero setting；If i₁T () is reversed polarity ripple, will correspond to the moment and be(j ＜ k≤n And kth section be aerial line) wave head wmm zero setting.

Multistage joint line compared to b type joint line, is equally based on aerial line, framework that cable is interspersed, therefore Aforementioned polarity rule is equally applicable；The two differs only in and more interference occurs in two time intervals of multistage circuit. Multistage series-parallel connection circuit, through rejecting after interference ripple, translates into the problem of the wave head recognizing corresponding polarity in two time intervals, this says Bright context of methods has versatility to multistage series-parallel connection circuit.

3.2 algorithms are realized

Algorithm to implement step as follows:

1) position of failure point d and fault distance interval d are primarily determined that based on single-ended power frequency amount；

2) wavelet transformation is carried out to fault current line modulus and calculate modulus maximum wmm；

3) according to formula (9) failure judgement point with the relation being connected vertex neighborhood: in neighborhood, then execution step 4)；In neighborhood In addition, then execution step 6)；

4) determine whether fault at junction point according to formula (10): be that in this neighborhood, junction point is trouble point, range finding knot Bundle；Otherwise determine time interval t according to formula (11), according to formula (12) Judging fault section；

5) according to the polar relationship determining in fault section, reject interference ripple with reference to series-parallel connection line construction；Afterwards according to formula (7) Calculate fault distance, range finding terminates；

6) according to formula (8), fault distance interval d is converted to time interval t₁And t₂；According to the polarity determining in fault section Relation, rejects interference ripple with reference to series-parallel connection line construction；Realize trouble point according to formula (7) to be accurately positioned, range finding terminates.

Although the above-mentioned accompanying drawing that combines is described to the specific embodiment of the present invention, not model is protected to the present invention The restriction enclosed, one of ordinary skill in the art should be understood that on the basis of technical scheme, and those skilled in the art are not Need to pay the various modifications that creative work can make or deformation still within protection scope of the present invention.

Claims (7)

1. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance, is characterized in that: includes following walking Rapid:

(1) it is based on circuit distributed parameter model, using the purely resistive of transition resistance, build fault location equation, assume initially that event There is certain point on certain section circuit in barrier, fault location equation search zero point is converted to this section of corresponding mapping function is asked Solution bare minimum point；

(2) every section of circuit is searched in respective length range with extreme point, comprehensive each section result obtains the area at trouble point place Between, failure judgement point and the relation being connected vertex neighborhood, if be located in neighborhood, execution step (3)；Beyond neighborhood, then execute Step (5)；

(3) junction point fault is determined whether by junction point failure criterion: be that in this neighborhood, junction point is trouble point, survey Away from end；Otherwise determine time interval t, by fault section criterion Judging fault section；

(4) determine the polar relationship of each current traveling wave in fault section, reject interference ripple with reference to series-parallel connection line construction；According to polarity Relation identification through section head end and fault point reflection echo once, through segment ends reflection echo once, it is right to record Answer the moment；Calculate fault distance, range finding terminates；

(5) fault distance interval is converted to time interval, according to the polar relationship determining in fault section, with reference to series-parallel connection circuit Structure rejects interference ripple；According to polar relationship identification through section head end and fault point reflection echo once, through segment ends Reflection echo once, the record corresponding moment；Calculate fault distance, range finding terminates；

Described step (4) method particularly includes: after determining fault section, according to three electric current row of structure determination of series-parallel connection circuit The polar relationship of ripple, then in the time interval delimited, detection respectively meets the wave head of polarity condition, corresponding according to wave head In the moment, calculate fault distance.

2. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (1), series-parallel connection circuit is aerial line, the alternatively distributed structure of cable, thus aerial line and cable are natural Circuit is divided into different sections by ground, and what each section referred to is exactly each built on stilts line segment and each cut cable.

3. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (2), the method in the interval of each section result localization of faults particularly as follows:

1) if the point in only one of which section in all results, remaining is each section junction point, takes the position of the point in this section；

2) if there being the point in two sections in all results, remaining is section junction point, takes the section between the point in two sections Junction point position；

3) if all results are section junction point, take the junction point position repeated.

4. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (4), the moment of echo is the direct conditions calculating fault distance, and this moment is unknown, needs Detected in respective time interval according to polar relationship.

5. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (3), the criterion connecting point failure is: junction point t_jDuring place's fault, traveling wave is in junction point t_jFront/rear two Constant through even reflection polarity in section:

Wherein, t₀The primary fault current traveling wave detecting for measurement end, l_j、l_j-1It is respectively jth section and -1 section of circuit of jth is long Degree, v_j、v_j-1It is respectively the traveling wave speed in jth section and -1 section of circuit of jth, m represents and carries out wavelet transformation to electric current line line ripple The Wavelet Modulus Maxima in corresponding moment in bracket afterwards, unit is wmm, sgn function stand polarity, and in formula, two formulas are set up simultaneously When, judge that trouble point is t_j.

6. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (3), fault section criterion is: traveling wave is through reflecting between trouble point and junction point once with reflection twice Polar relationship depend on the type of guilty culprit section, polarity is identical, fault generation be described in built on stilts line segment, opposite polarity, Illustrate fault occur in cut cable it may be assumed that

Wherein, t ' is in time interval, is arrived through junction point, fault point reflection wave head once according to what polar relationship picked out Reach the moment of measurement end.

7. a kind of series-parallel connection line one-end Method of Traveling Wave Fault Ranging interval based on fault distance as claimed in claim 1, its Feature is: in described step (4), (5), interference ripple elimination method is: from the aspect of polarity of traveling wave and section length two, will be right Wave head to be identified is likely to result in the wavelet modulus maxima zero setting of the wave head of interference.