CN102023275A - Circuit single-end ranging method based on phase aberration characteristic of positioning function - Google Patents

Abstract

The invention belongs to the technical field of power system relay protection, and discloses a circuit single-end ranging method based on phase aberration characteristic of positioning function. The method deduces an operating voltage of reference positions and a fault point voltage based on distribution parameters by using electric quantity of a single end, and constructs a positioning function. When the reference positions are positioned on the left side and the right side of fault point, the positioning function has different phase characteristics; and when the reference positions are changed in front and back of the fault point, the phase of the positioning function has a unique stepped aberration. A circuit is subjected to N equal distribution, the equal distribution area containing the fault point is determined by using the phase characteristics, the step length is further reduced to determine the phase aberration position in the area, and then quick fault positioning of the single end can be realized. The method overcomes the defects of the traditional single-end ranging method, and theoretically is not affected by the factors such as distributed capacitance, transition resistance, opposite side running mode, communication facilities, load current and the like. The algorithm is simple, reliable and easy to realize, and the use value of the method is strong.

Description

Line one-end distance-finding method based on mapping function SPA sudden phase anomalies characteristic

Technical field

The present invention relates to the relay protection of power system technical field, specifically relate to adopt the line one-end fault ranging method of mapping function SPA sudden phase anomalies characteristic.

Background technology

Ultra-high-tension power transmission line is being served as the vital task of electric energy transmitting, process with a varied topography, the probability that fault takes place is very big, the safe operation of serious threat electrical network.At present, the electric pressure of China just develops to 1000kV from 500kV, and transmission line capability is increasing, and it is particularly important that its security and stability seems.When breaking down, ascertaining the reason fast and getting rid of line fault rapidly is the important behave that guarantees reliable power supply, and localization of fault is the prerequisite of fixing a breakdown accurately, is the important evidence of searching failure point of power transmission line, has important economic benefit and social benefit.In all line fault, single-line to ground fault accounts for more than 80%, therefore, has stronger practical meaning in engineering based on a kind of one-end fault ranging algorithm of singlephase earth fault that is applicable to of distribution parameter research.

Fault localization mainly contains single-ended method and both-end method at present.Can realize accurate localization of fault on the both-end method principle, but need know the electric parameters of both-end, also be subject to the influence of both-end sampled value synchronism in actual the use.Single-ended impedance method fault localization only need be measured a side information, have low to hardware requirement, be easy to realize and advantage such as algorithm is stable, in the mesolow circuit, obtained to use widely.At present, the method for single end distance measurement mainly can be divided into two classes, and a class is an impedance method, and another kind of is traveling wave method.Traveling wave method utilizes the transmission character of fault transient travelling wave to find range, and the precision height is not influenced by the method for operation, excessive resistance etc., but very high to the sampling rate requirement, needs special wave recording device, does not obtain substantial application at present.The impedance that impedance method utilizes voltage after the fault, the magnitude of current to calculate fault loop is found range according to the characteristic that line length is directly proportional with impedance, and is simple and reliable, but is subjected to the influence of the factors such as transition resistance, the incomplete symmetry of circuit of fault.Because the influence of ultra-high-tension power transmission line distributed capacitance, when being applied to the ultra-high-tension power transmission line fault localization, the single-ended impedance method has very big error, during particularly middle high resistant short trouble, its range finding result understands substantial deviation true fault distance, can not satisfy on-the-spot application requirements.Can not directly apply to the fault localization of ultra-high-tension power transmission line based on the single-ended impedance method of lumped parameter.

Summary of the invention

For solving the technical matters that above-mentioned method of single end distance measurement exists, the invention provides a kind of line one-end fault ranging method based on mapping function SPA sudden phase anomalies characteristic, may further comprise the steps:

(1) as if A phase earth fault, high-tension line m end A phase voltage, electric current after the extraction fault

With m end negative phase-sequence, zero-sequence current

Determine the zero sequence compensation coefficient k _i, the reference position operating voltage And the voltage of trouble spot

Construct corresponding mapping function f thus;

(2) zone that initially comprises the trouble spot is (l _Begin, l _End)=(0, l _Mn);

(3) will comprise the zone (l of trouble spot _Begin, l _End) carry out the N five equilibrium, utilize m end electric parameters to derive, draw (l _Begin, l _End) the mapping function phase angle at each Along ent place in the zone; Judge the position relation of Along ent and trouble spot according to mapping function phase place size:

1) mapping function phase angle ∈ (90 °, 90 °), Along ent are positioned at the left side, trouble spot;

2) mapping function phase angle ∈ (90 °, 270 °), Along ent is positioned at the right side, trouble spot;

Criterion finds two adjacent Along ent k and k+1 thus, and its mapping function phase angle lays respectively at (90 °, 90 °) and (90 °, 270 °), then comprises the zone (l of trouble spot this moment _Begin, l _End)=(l _k, l _K+1); Set branches such as a minimum zone threshold values Δ l _Set, repeat (3) until l _End-l _Begin＜Δ l _Set, then can draw the subregion (l such as minimum that comprise the trouble spot _Beginm, l _Endm);

(4) comprising the subregion (l such as minimum of trouble spot _Beginm, l _Endm) interior according to l _MxAt l _MfBefore and after when changing the mapping function phase place unique this feature of phase step type saltus step can take place positions:

1) determines step delta l;

2) reference position l _MxFrom l _BeginmBeginning is that step-length is incremented to l with Δ l _Endm, the phase angle of calculating each point place mapping function;

3) seek definite a certain reference position l _Mx, make and satisfy at l _Mx-Δ l place mapping function phase angle is positioned at (90 °, 90 °), at l _MxPlace's mapping function phase angle is positioned at (90 °, 270 °), and then abort situation f is apart from the fault distance l of m end _Mf=l _Mx-Δ l/2.

The described zero sequence compensation coefficient of step (1) can obtain by equation for transmission line, and computing formula is:

$k_i\left(l_{\mathrm{mf}}\right)=\frac{{\mathrm{<figure-callout\; id="0"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}+Z_{m0}(\cosh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}})}{{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}$

Wherein, Z _C0, Z _C1Respectively the nulling preface, just (bear) wave impedance of preface; Z _M0Refer to the zero sequence equivalent impedance of m side system; l _MfRefer to the distance that m holds abort situation f to order.

Operating voltage with reference position x is an example, step (1) reference position voltage can find the solution by the phase voltage electric current of m end, computing formula is:

${\stackrel{\&CenterDot;}{U}}_{\mathrm{op}\&CenterDot;A}\left(l_{\mathrm{mx}}\right)={\stackrel{\&CenterDot;}{U}}_{\mathrm{mA}}-{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\tanh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mx}}[{\stackrel{\&CenterDot;}{I}}_{\mathrm{mA}}+k_i\left(l_{\mathrm{mx}}\right){\stackrel{\&CenterDot;}{I}}_{m0}]$

Wherein, l _MxBe the distance of x point to the m end, Be circuit m end A phase voltage, electric current.

The described fault point voltage of step (1)

Can find the solution by the phase voltage and the preface electric current of m end, computing formula is:

Wherein,

Be circuit positive sequence impedance angle;

α is the negative-sequence current that measures of m end and the angle between the branch road negative-sequence current of trouble spot.

The described mapping function of step (1) can be by phase voltage, reference position operating voltage and the false voltage structure of m end, and computing formula is:

$f\left(l_{\mathrm{mx}}\right)=\frac{{\stackrel{\&CenterDot;}{U}}_{\mathrm{mA}}-{\stackrel{\&CenterDot;}{U}}_{\mathrm{fA}}}{{\stackrel{\&CenterDot;}{U}}_{\mathrm{op}\&CenterDot;A}\left(l_{\mathrm{mx}}\right)-{\stackrel{\&CenterDot;}{U}}_{\mathrm{fA}}}$

Wherein, The fault point voltage that finger is calculated out by the phase voltage and the preface electric current of m end.

Δ l described in the step (3) _SetCan require to carry out flexibly the setting of interval size according to realistic accuracy.

Step delta l described in the step (4) can set the requirement of distance accuracy and range finding speed according to reality.

This method hunting zone is

(wherein,

Expression is big and immediate integer than x), the classic method hunting zone is

Be to improve precision, Δ l gets enough little and N when rationally getting higher value,

This method hunting zone has good rapidity much smaller than classic method.

The present invention utilizes the SPA sudden phase anomalies characteristic of mapping function to carry out localization of fault accurately, mainly contains following advantage:

Adopt distributed parameter, be not subjected to the influence of distributed capacitor, be applicable to any electric pressure, particularly the mesohigh circuit;

Adopt single-ended electric parameters, be not subjected to the influence of the method for operation, communications service;

Accurately localization of fault can shorten the malfunction elimination time, accelerates to restore electricity, and safe, the stable and economical operation of electric system is had very important significance.

Description of drawings

Below in conjunction with accompanying drawing the present invention is elaborated:

Fig. 1 is for using the transmission system synoptic diagram of the inventive method;

System's equivalent net of (negative, zero) preface just when Fig. 2 is troubles inside the sample space;

Fig. 3 is the phase error family curve with m end negative-sequence current estimation trouble spot negative-sequence current;

Fig. 4 is an electric current and voltage phasor graph behind the singlephase earth fault; Wherein,

Fig. 4 a is the electric current and voltage phasor graph of fault between m end and reference position x point;

Fig. 4 b is the electric current and voltage phasor graph of fault between n end and reference position x point;

Fig. 5 is the phase characteristic curve of mapping function;

Fig. 6 is the error curve diagram that abort situation and load current influence the AG fault localization;

Fig. 7 is the error curve diagram that transition resistance and abort situation influence the AG fault localization;

Fig. 8 is the error curve diagram that the influence of AG fault localization takes place the 51km place for transition resistance and load current.

Embodiment

The line one-end fault ranging method based on mapping function SPA sudden phase anomalies characteristic that the present invention proposes in conjunction with the accompanying drawings, below provides the detailed description of embodiment and concrete operating process:

Figure 1 shows that Beijing-Tangshan electrical network 500kV transmission system of using the inventive method, circuit mn two ends equivalent source phase angle difference is θ, and the two power supply amplitude is respectively per unit value and 1 times of per unit value of 1.05 times.Transmission line of electricity total length 300km.Line parameter circuit value: R ₁=0.02083 Ω/km, L ₁=0.8948mH/km, C ₁=0.0129 μ F/km, R ₀=0.1148 Ω/km, L ₀=2.2886mH/km, C ₀=0.00523 μ F/km.

The both sides systematic parameter:

Z _m1＝4.2643+85.1453iΩ、Z _m0＝0.6+29.0911iΩ

Z _n1＝7.9956+159.6474iΩ、Z _n0＝2.0+37.4697iΩ

System's equivalent net of (negative, zero) preface just when Figure 2 shows that troubles inside the sample space can get trouble spot and the relation of protecting between each electric parameters of installation place according to equivalent network:

$\left\{\begin{array}{c}{\stackrel{\&CenterDot;}{U}}_{\mathrm{mi}}={\stackrel{\&CenterDot;}{U}}_{\mathrm{fi}}\cosh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}+{\stackrel{\&CenterDot;}{I}}_{\mathrm{fi}}{Z}_{\mathrm{ci}}\sinh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}\\ {\stackrel{\&CenterDot;}{I}}_{\mathrm{mi}}={\stackrel{\&CenterDot;}{I}}_{\mathrm{fi}}\cosh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}+{\stackrel{\&CenterDot;}{U}}_{\mathrm{fi}}\sinh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}/Z_{\mathrm{ci}}\end{array}\right.---\left(\text{1}\right)$

Wherein, i=1,2,0;

Positive and negative, residual voltage and electric current for m end;

Positive and negative, residual voltage and electric current for trouble spot f place; l _MfBe the distance of trouble spot f to the m end.Can get by formula (1):

${\stackrel{\&CenterDot;}{U}}_{\mathrm{mi}}=\frac{1}{\cosh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}}{\stackrel{\&CenterDot;}{U}}_{\mathrm{fi}}+Z_{\mathrm{ci}}\tanh {\mathrm{\&gamma;}}_i{l}_{\mathrm{mf}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{mi}}---\left(2\right)$

With A is example mutually, and the voltage that can be got the m place by formula (2) is

${\stackrel{\&CenterDot;}{U}}_{\mathrm{mA}}={\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="1"\; label="mA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">mA</figure-callout>}1}+{\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="2"\; label="mA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">mA</figure-callout>}2}+{\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="0"\; label="mA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">mA</figure-callout>}0}$

$=\frac{1}{\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}{\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="1"\; label="kA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">kA</figure-callout>}1}+{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\tanh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{<figure-callout\; id="1"\; label="mA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">mA</figure-callout>}1}+\frac{1}{\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}{\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="2"\; label="kA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">kA</figure-callout>}2}+{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\tanh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{<figure-callout\; id="2"\; label="mA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">mA</figure-callout>}2}+\frac{1}{\cosh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}}{\stackrel{\&CenterDot;}{U}}_{\mathrm{<figure-callout\; id="0"\; label="kA"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">kA</figure-callout>}0}+{\mathrm{<figure-callout\; id="0"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\tanh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}{\stackrel{\&CenterDot;}{I}}_{\mathrm{mA}0}---\left(3\right)$

$=\frac{1}{\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}{\stackrel{\&CenterDot;}{U}}_{\mathrm{fA}}+{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\tanh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}({\stackrel{\&CenterDot;}{I}}_{\mathrm{mA}}+k_i{\stackrel{\&CenterDot;}{I}}_{m0})$

Wherein, k _iBe the zero sequence compensation coefficient, $k_i\left(l_{\mathrm{mf}}\right)=\frac{{\mathrm{<figure-callout\; id="0"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}+Z_{m0}(\cosh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}})}{{\mathrm{<figure-callout\; id="1"\; label="Z\; c"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">Z</figure-callout>}}_c\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}.$

Figure 3 shows that with the phase error family curve of m end negative-sequence current estimation trouble spot negative-sequence current, have following relation between m end negative-sequence current and the trouble spot branch road negative-sequence current:

$\frac{{\stackrel{\&CenterDot;}{I}}_{f2}}{{\stackrel{\&CenterDot;}{I}}_{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HSA00000285718000032.png"\; state="\{\{state\}\}">m</figure-callout>}2}}=(\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}+\tanh {\mathrm{\&gamma;}}_1{l}_m\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}})(1+\frac{\tanh {\mathrm{\&gamma;}}_1(l_m+l_{\mathrm{mf}})}{\tanh {\mathrm{\&gamma;}}_1(l_n+l_{\mathrm{mn}}-l_{\mathrm{mf}})})---\left(4\right)$

Wherein, l _MnBe line length; l _m, l _nBe respectively virtual equivalent line length by m, the decision of n side negative phase-sequence system impedance, and l _m=atanh (Z _M2/ Z _C1)/γ ₁, l _n=atanh (Z _N2/ Z _C1)/γ ₁Know by Fig. 3,

With

The maximum phase estimation error of estimation is less than 0.35 °, and therefore, the phase angle of trouble spot branch road negative-sequence current can be approximately the negative-sequence current phase angle of protection installation place in the actual computation.

Figure 4 shows that electric current and voltage phasor graph behind the singlephase earth fault, by Fig. 4 a as can be known, when fault is between m end and reference position x point, fault point voltage

With

Between, this moment Argf (l _Mx) ∈ (90 °, 270 °).By Fig. 4 b as can be known, when fault is between reference position x point and n end, fault point voltage

With

A side, this moment Argf (l _Mx) ∈ (90 °, 90 °).

Figure 5 shows that the phase characteristic curve of mapping function, utilize the SPA sudden phase anomalies characteristic comparison reference position of mapping function and the relation of abort situation, work as l _Mx=l _Mf ^-The time, Argf (l _Mx) ∈ (90 °, 90 °); Work as l _Mx=l _Mf ⁺The time, Argf (l _Mx) ∈ (90 °, 270 °), only work as l _MxBy l _Mf ^-Increase to l _Mf ⁺The time, the mapping function phase place can enter (90 °, 270 °) from (90 °, 90 °), and promptly this moment, a phase step type sudden change can take place in the mapping function phase place, and fault signature is obvious.

Table 1 is depicted as abort situation and load current to AG affection of fault location situation, and wherein, θ is the phase angle difference of mn both sides system power supply, and θ gets 10 °～60 ° in the test, and abort situation is got the various various combinations of 15km～290km, and the range finding result sees table 1 for details.The relative error curve as shown in Figure 6.

Table 1 abort situation and load current are to the AG affection of fault location

Abort situation/(km)

θ＝10°?

θ＝20°?

θ＝30°?

θ＝40°?

θ＝50°?

θ＝60°?

15?

15.005?

14.985?

14.975?

14.965?

14.955?

14.955?

45?

45.015?

44.985?

44.965?

44.945?

44.935?

44.925?

65?

65.015?

64.995?

64.965?

64.955?

64.935?

64.935?

85?

85.005?

84.985?

84.975?

84.955?

84.955?

84.955?

105?

104.995?

104.985?

104.975?

104.965?

104.965?

104.965?

125?

124.995?

124.985?

124.975?

124.975?

124.975?

124.985?

165?

164.995?

164.985?

164.985?

164.995?

164.995?

165.015?

180?

179.995?

179.985?

179.995?

179.995?

180.005?

180.015?

205?

204.995?

204.995?

204.995?

204.995?

205.005?

205.025?

230?

229.995?

229.985?

229.985?

229.985?

229.995?

230.005?

245?

245.005?

244.985?

244.965?

244.965?

244.965?

244.975?

265?

265.005?

264.965?

264.925?

264.895?

264.885?

264.885?

275?

275.005?

274.965?

274.915?

274.875?

274.835?

274.805?

290?

290.015?

289.955?

289.895?

289.845?

289.805?

289.765?

By table 1 and Fig. 6 as can be seen, under the various various combination situations of abort situation and load current, distance accuracy is all very high.The AG fault takes place at 290km in extreme case θ=60 °, and relative error only is 0.0783%.Therefore, one-end fault ranging method of the present invention is not subjected to the influence of load current substantially.

Table 2 is depicted as transition resistance and abort situation to AG affection of fault location situation, and it is that 0～300 Ω, abort situation are the various various combinations of 5～290km that transition resistance is adopted in test, and the range finding result sees table 2 for details.The relative error curve as shown in Figure 7.

Table 2 transition resistance and abort situation are to the AG affection of fault location

By table 2 and Fig. 7 as can be seen, under the various various combination situations of abort situation and load current, distance accuracy is all very high.Extreme case is in the AG fault of 290km generation through 300 Ω transition resistances, and relative error only is 0.9350%.Therefore, it is very little that one-end fault ranging method of the present invention is subjected to the influence of transition resistance.

Table 3 is depicted as transition resistance and load current to the AG of 51km place affection of fault location situation, and wherein, θ is the phase angle difference of mn both sides system power supply.It is that 15～300 Ω, the both sides power supply phase angle difference θ of system are 10 °～60 ° various various combinations that transition resistance is adopted in test, and the range finding result sees table 3 for details.The relative error curve is shown in Fig. 8.

Table 3 transition resistance and load current are to the AG of 51km place affection of fault location

Transition resistance Rg/ (Ω)

θ＝10°?

θ＝20°?

θ＝30°?

θ＝40°?

θ＝50°?

θ＝60°?

15?

51.235?

51.235?

51.225?

51.215?

51.215?

51.205?

30?

51.465?

51.455?

51.445?

51.425?

51.415?

51.405?

50?

51.765?

51.735?

51.715?

51.695?

51.665?

51.645?

75?

52.125?

52.085?

52.045?

51.995?

51.955?

51.915?

100?

52.475?

52.415?

52.345?

52.285?

52.215?

52.155?

125?

52.825?

52.725?

52.635?

52.545?

52.455?

52.375?

150?

53.165?

53.025?

52.905?

52.785?

52.675?

52.575?

175?

53.495?

53.315?

53.155?

53.015?

52.875?

52.755?

200?

53.825?

53.595?

53.405?

53.225?

53.065?

52.915?

225?

54.135?

53.865?

53.635?

53.425?

53.235?

53.065?

250?

54.445?

54.125?

53.845?

53.605?

53.395?

53.205?

275?

54.755?

54.375?

54.055?

53.785?

53.545?

53.335?

300?

55.055?

54.615?

54.255?

53.945?

53.685?

53.445?

By table 3 and Fig. 8 as can be seen, under the various various combination situations of abort situation and load current, distance accuracy all satisfies the actual requirement of engineering.The AG fault takes place through 300 Ω transition resistances in θ=10 ° in extreme case, and relative error is 1.3517% only, less than 1.5%, and engineering demands.Therefore, it is very little that the present invention is subjected to the influence of transition resistance, load current composite factor.

The one-end fault ranging method that table 1～3, Fig. 6～8 show the present invention jointly to be carried has overcome the influence to distance accuracy of distributed capacitance and high resistance ground well, under transition resistance, load current, the isoparametric various combinations of abort situation, distance accuracy is all very high, has good engineering practicability.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (7)

1. based on the line one-end distance-finding method of mapping function SPA sudden phase anomalies characteristic, it is characterized in that, may further comprise the steps:

(1) as if A phase earth fault, high-tension line m end A phase voltage, electric current after the extraction fault With m end negative phase-sequence, zero-sequence current

Determine the zero sequence compensation coefficient k _i, the reference position operating voltage

And the voltage of trouble spot

Construct corresponding mapping function f thus;

(2) zone that initially comprises the trouble spot is (l _Begin, l _End)=(0, l _Mn);

(3) will comprise the zone (l of trouble spot _Begin, l _End) carry out the N five equilibrium, utilize m end electric parameters to derive, draw (l _Begin, l _End) the mapping function phase angle at each Along ent place in the zone; Judge the position relation of Along ent and trouble spot according to mapping function phase place size:

1) mapping function phase angle ∈ (90 °, 90 °), Along ent are positioned at the left side, trouble spot;

2) mapping function phase angle ∈ (90 °, 270 °), Along ent is positioned at the right side, trouble spot;

Criterion finds two adjacent Along ent k and k+1 thus, and its mapping function phase angle lays respectively at (90 °, 90 °) and (90 °, 270 °), then comprises the zone (l of trouble spot this moment _Begin, l _End)=(l _k, l _K+1); Set branches such as a minimum zone threshold values Δ l _Set, repeat (3) until l _End-l _Begin＜Δ l _Set, then can draw the subregion (l such as minimum that comprise the trouble spot _Beginm, l _Endm);

(4) comprising the subregion (l such as minimum of trouble spot _Beginm, l _Endm) interior according to l _MxAt l _MfBefore and after when changing the mapping function phase place unique this feature of phase step type saltus step can take place positions:

1) determines step delta l;

2) reference position l _MxFrom l _BeginmBeginning is that step-length is incremented to l with Δ l _Endm, the phase angle of calculating each point place mapping function;

3) seek definite a certain reference position l _Mx, make and satisfy at l _Mx-Δ l place mapping function phase angle is positioned at (90 °, 90 °), at l _MxPlace's mapping function phase angle is positioned at (90 °, 270 °), and then abort situation f is apart from the fault distance l of m end _Mf=l _Mx-Δ l/2.

2. the method for claim 1 is characterized in that, the zero sequence compensation coefficient described in the step (1) can obtain by equation for transmission line, and computing formula is:

$k_i\left(l_{\mathrm{mf}}\right)=\frac{Z_{c0}\sinh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-Z_{c1}\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}+Z_{m0}(\cosh {\mathrm{\&gamma;}}_0{l}_{\mathrm{mf}}-\cosh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}})}{Z_{c1}\sinh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mf}}}$

Wherein, Z _C0, Z _C1Respectively the nulling preface, just (bear) wave impedance of preface; Z _M0Refer to the impedance of m side system zero sequence equivalent; l _MfRefer to the distance that m holds abort situation f to order.

3. the method for claim 1 is characterized in that, the reference position voltage described in the step (1) is found the solution by the phase voltage electric current of m end, and computing formula is:

${\stackrel{\&CenterDot;}{U}}_{\mathrm{op}\&CenterDot;A}\left(l_{\mathrm{mx}}\right)={\stackrel{\&CenterDot;}{U}}_{\mathrm{mA}}-Z_{c1}\tanh {\mathrm{\&gamma;}}_1{l}_{\mathrm{mx}}[{\stackrel{\&CenterDot;}{I}}_{\mathrm{mA}}+k_i\left(l_{\mathrm{mx}}\right){\stackrel{\&CenterDot;}{I}}_{m0}]$

Wherein, l _MxBe the distance of x point to the m end,

Be circuit m end A phase voltage, electric current.

4. the method for claim 1 is characterized in that, the fault point voltage described in the step (1)

Phase voltage and preface electric current by the m end are found the solution, and computing formula is:

Wherein,

Be circuit positive sequence impedance angle;

α is the negative-sequence current that measures of m end and the angle between the branch road negative-sequence current of trouble spot.

5. the method for claim 1 is characterized in that, the mapping function described in the step (1) is by phase voltage, reference position operating voltage and the false voltage structure of m end, and computing formula is:

$f\left(l_{\mathrm{mx}}\right)=\frac{{\stackrel{\&CenterDot;}{U}}_{\mathrm{mA}}-{\stackrel{\&CenterDot;}{U}}_{\mathrm{fA}}}{{\stackrel{\&CenterDot;}{U}}_{\mathrm{op}\&CenterDot;A}\left(l_{\mathrm{mx}}\right)-{\stackrel{\&CenterDot;}{U}}_{\mathrm{fA}}}$

Wherein,

The fault point voltage that finger is calculated out by the phase voltage and the preface electric current of m end.

6. the method for claim 1 is characterized in that, the Δ l described in the step (3) _SetRequire to carry out flexibly the setting of interval size according to realistic accuracy.

7. the method for claim 1 is characterized in that, the step delta l described in the step (4) sets the requirement of distance accuracy and range finding speed according to reality.

Images