CN103293441A - Line single-phase earth fault single-terminal location method implemented by aid of distributed parameters - Google Patents

Abstract

The invention discloses a line single-phase earth fault single-terminal location method implemented by the aid of distributed parameters. The line single-phase earth fault single-terminal location method includes computing an amplitude value of voltage drop from a single-phase earth fault point to a power transmission line protection setting range position by the aid of fault-phase voltages, fault-phase currents, fault-phase negative-sequence currents and a zero-sequence current at a power transmission line protection mounting position; selecting an initial value I<x> of the fault distance, sequentially increasing a value of the fault distance by a step delta I on the basis of the initial value I<x>, and sequentially computing a location function value f(I<x>) of each point on a power transmission line until the increased value of the fault distance is equal to the total length of the power transmission line; selecting the distance from the power transmission line protection mounting position to the point with the minimum location function value f(I<x>) as the fault distance. The line single-phase earth fault single-terminal location method has the advantages that voltage and current transmission physical characteristics of the power transmission line are described by the distributed parameters, the location precision is unaffected by earth capacitance of the power transmission line, and the line single-phase earth fault single-terminal location method is suitable for single-phase earth fault single-terminal location for power transmission lines in any voltage grades, and is particularly applicable to ultrahigh-voltage/extra-high-voltage power transmission line single-phase earth fault single-terminal location.

Description

Utilize distribution parameter to realize the line single phase grounding failure method of single end distance measurement

Technical field

The present invention relates to electric system one-end fault ranging technical field, specifically relate to a kind of distribution parameter that utilizes and realize the line single phase grounding failure method of single end distance measurement.

Background technology

Divide according to the electric parameters source, fault distance-finding method mainly is divided into both-end distance measuring method and method of single end distance measurement.Both-end distance measuring method utilizes transmission line of electricity two ends electric parameters to carry out localization of fault, need obtain the opposite end electric parameters by data transmission channel, and is strong to the data transmission channel dependence, also is subject to the influence of both-end sampled value synchronism in actual the use.Ultrahigh voltage alternating current transmission lines is long-distance transmission line often, and laying the required data transmission channel of range finding needs the additional investment substantial contribution, and therefore, method of single end distance measurement has more practicality than both-end distance measuring method.Method of single end distance measurement only utilizes transmission line of electricity one end electric parameters to carry out localization of fault, need not communication and data sync equipment, and operating cost is low and algorithm stable, obtains widespread use in high, normal, basic pressure transmission line.

At present, method of single end distance measurement mainly is divided into traveling wave method and impedance method.Traveling wave method utilizes the transmission character of fault transient travelling wave to carry out one-end fault ranging, 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, application cost height.Impedance method utilizes voltage, the magnitude of current after the fault to calculate the fault loop impedance, carry out one-end fault ranging according to the characteristic that line length is directly proportional with impedance, simple and reliable, but it is serious that distance accuracy is subjected to factor affecting such as transition resistance and load current, when especially transition resistance is big, impedance method range finding result understands substantial deviation true fault distance, even the range finding failure occurs.Because UHV (ultra-high voltage), the bigger capacitance current of UHV transmission line existence along the line, in UHV (ultra-high voltage), UHV transmission line take place during the high resistant short trouble, single-ended impedance method range finding result understands substantial deviation true fault distance, can not satisfy on-the-spot application requirements.Therefore, the single-ended impedance method of employing lumped parameter modeling can not directly apply to the one-end fault ranging of UHV (ultra-high voltage), UHV transmission line.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, overcome transition resistance and load current to the influence of distance accuracy and provide a kind of, the distance accuracy height, range measurement principle is simple, and practical a kind of distribution parameter that utilizes is realized the line single phase grounding failure method of single end distance measurement.

For finishing above-mentioned purpose, the present invention adopts following technical scheme:

Utilize distribution parameter to realize the line single phase grounding failure method of single end distance measurement, it is characterized in that, comprise following sequential steps:

(1) the fault phase voltage of protector measuring line protection installation place

, the fault phase current

, fault phase negative-sequence current And zero-sequence current

Wherein, φ=A phase, B phase, C phase;

(2) protective device calculates singlephase earth fault and puts the amplitude Δ U of the voltage drop at line protection setting range place:

$\mathrm{\&Delta;U}=\left|{\stackrel{.}{U}}_{\mathrm{\&phi;}}\right|\frac{\sin (\mathrm{\&theta;}-\mathrm{\&beta;}-\mathrm{\&gamma;})}{\sin (\mathrm{\&alpha;}+\mathrm{\&gamma;})}$

Wherein, φ=A phase, B phase, C phase; Be the fault phase voltage;

Be the fault phase current;

Be fault phase negative-sequence current;

Be zero-sequence current; l _SetBe the protection setting range; Z ₀System's zero sequence equivalent impedance for the line protection installation place; Z _C1, Z _C0Be respectively transmission line of electricity positive sequence wave impedance, zero sequence wave impedance; α=Arg (Z _C1Th (γ ₁l _Set));

γ ₁, γ ₀Be respectively transmission line of electricity positive sequence propagation coefficient, zero sequence propagation coefficient; $\mathrm{\&gamma;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{I}}_{\mathrm{\&phi;}}+(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}-1){\stackrel{.}{I}}_0}{{\stackrel{.}{I}}_{\mathrm{\&phi;}2}}\right)$ ； $\mathrm{\&theta;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{U}}_{\mathrm{\&phi;}}}{{\stackrel{.}{U}}_{\mathrm{\&phi;}}-Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)}\right)$ Th (.) is hyperbolic tangent function; Ch (.) is hyperbolic cosine function; Sh (.) is hyperbolic sine function;

(3) to choose the fault distance initial value be l to protective device _x, calculate apart from line protection installation place l _xThe range finding functional value f (l of point _x):

$\begin{array}{c}f\left(l_x\right)=|\mathrm{\&Delta;U}-|Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)}\right){\stackrel{.}{I}}_0)\\ Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)\left|\right|\end{array}$

(4) fault distance increases one by one with step delta l, returns step (3), successively the range finding functional value f (l of every bit on the computing electric power line _x) until the transmission line of electricity total length, choose range finding functional value f (l _x) minimum point is fault distance apart from the distance of line protection installation place.

Characteristics of the present invention and technological achievement:

The inventive method adopts distribution parameter to describe the physical characteristics of transmission line of electricity voltage, current delivery, distance accuracy is not subjected to the influence of transmission line of electricity ground capacitance, be applicable to any electric pressure transmission line one-phase earth fault single end distance measurement, be particularly useful for UHV (ultra-high voltage), UHV transmission line.The inventive method is carried out the transmission line one-phase earth fault single end distance measurement according to the corresponding range finding functional value minimum principle of singlephase earth fault point, transition resistance and load current have been overcome to the influence of distance accuracy, the distance accuracy height, range measurement principle is simple, and is practical.

Description of drawings

Fig. 1 is for using circuit transmission system synoptic diagram of the present invention.

Embodiment

Below in conjunction with embodiment technical scheme of the present invention is done further detailed presentations.

Fig. 1 is for using circuit transmission system synoptic diagram of the present invention.TV is that voltage transformer (VT), TA are current transformer among Fig. 1.Protective device is sampled to the current waveform of the voltage and current mutual inductor TA of the voltage transformer (VT) TV of line protection installation place and is obtained voltage, current instantaneous value, and protective device utilizes the fault phase voltage of Fourier algorithm computing electric power line protection installation place to its voltage that collects, current instantaneous value then

, the fault phase current

, fault phase negative-sequence current

And zero-sequence current

Wherein, φ=A, B, C phase.

Protective device calculates singlephase earth fault and puts the amplitude Δ U of the voltage drop at line protection setting range place:

$\mathrm{\&Delta;U}=\left|{\stackrel{.}{U}}_{\mathrm{\&phi;}}\right|\frac{\sin (\mathrm{\&theta;}-\mathrm{\&beta;}-\mathrm{\&gamma;})}{\sin (\mathrm{\&alpha;}+\mathrm{\&gamma;})}$

Wherein, φ=A phase, B phase, C phase; Be the fault phase voltage;

Be the fault phase current;

Be fault phase negative-sequence current;

Be zero-sequence current; l _SetBe the protection setting range; Z ₀System's zero sequence equivalent impedance for the line protection installation place; Z _C1, Z _C0Be respectively transmission line of electricity positive sequence wave impedance, zero sequence wave impedance; α=Arg (Z _C1Th (γ ₁l _Set));

γ ₁, γ ₀Be respectively transmission line of electricity positive sequence propagation coefficient, zero sequence propagation coefficient; $\mathrm{\&gamma;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{I}}_{\mathrm{\&phi;}}+(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}-1){\stackrel{.}{I}}_0}{{\stackrel{.}{I}}_{\mathrm{\&phi;}2}}\right)$ ； $\mathrm{\&theta;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{U}}_{\mathrm{\&phi;}}}{{\stackrel{.}{U}}_{\mathrm{\&phi;}}-Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)}\right)$ Th (.) is hyperbolic tangent function; Ch (.) is hyperbolic cosine function; Sh (.) is hyperbolic sine function.

It is l that protective device is chosen the fault distance initial value _x, calculate apart from line protection installation place l _xThe range finding functional value f (l of point _x):

$\begin{array}{c}f\left(l_x\right)=|\mathrm{\&Delta;U}-|Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)}\right){\stackrel{.}{I}}_0)\\ Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)\left|\right|\end{array}---\left(1\right)$

Fault distance increases one by one with step delta l, recycles formula (1) the range finding functional value f (l of every bit on the computing electric power line successively _x), until the transmission line of electricity total length, choose range finding functional value f (l _x) minimum point is fault distance apart from the distance of line protection installation place.

The inventive method adopts distribution parameter to describe the physical characteristics of transmission line of electricity voltage, current delivery, distance accuracy is not subjected to the influence of transmission line of electricity ground capacitance, be applicable to any electric pressure transmission line one-phase earth fault single end distance measurement, be particularly useful for UHV (ultra-high voltage), UHV transmission line singlephase earth fault single end distance measurement.The inventive method is carried out the transmission line one-phase earth fault single end distance measurement according to the corresponding range finding functional value minimum principle of singlephase earth fault point, transition resistance and load current have been overcome to the influence of distance accuracy, the distance accuracy height, range measurement principle is simple, and is practical.

The above only is preferred embodiment of the present invention; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the present invention discloses, the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.

Claims (1)

1. utilize distribution parameter to realize the line single phase grounding failure method of single end distance measurement, it is characterized in that, comprise following sequential steps:

(1) the fault phase voltage of protector measuring line protection installation place

, the fault phase current

, fault phase negative-sequence current

And zero-sequence current

Wherein, φ=A phase, B phase, C phase;

(2) protective device calculates singlephase earth fault and puts the amplitude Δ U of the voltage drop at line protection setting range place:

$\mathrm{\&Delta;U}=\left|{\stackrel{.}{U}}_{\mathrm{\&phi;}}\right|\frac{\sin (\mathrm{\&theta;}-\mathrm{\&beta;}-\mathrm{\&gamma;})}{\sin (\mathrm{\&alpha;}+\mathrm{\&gamma;})}$

Wherein, φ=A phase, B phase, C phase;

Be the fault phase voltage;

Be the fault phase current;

Be fault phase negative-sequence current;

Be zero-sequence current; l _SetBe the protection setting range; Z ₀System's zero sequence equivalent impedance for the line protection installation place; Z _C1, Z _C0Be respectively transmission line of electricity positive sequence wave impedance, zero sequence wave impedance; α=Arg (Z _C1Th (γ ₁l _Set));

γ ₁, γ ₀Be respectively transmission line of electricity positive sequence propagation coefficient, zero sequence propagation coefficient; $\mathrm{\&gamma;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{I}}_{\mathrm{\&phi;}}+(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}-1){\stackrel{.}{I}}_0}{{\stackrel{.}{I}}_{\mathrm{\&phi;}2}}\right)$ ； $\mathrm{\&theta;}=\mathrm{Arg}\left(\frac{{\stackrel{.}{U}}_{\mathrm{\&phi;}}}{{\stackrel{.}{U}}_{\mathrm{\&phi;}}-Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)}\right)$ Th (.) is hyperbolic tangent function; Ch (.) is hyperbolic cosine function; Sh (.) is hyperbolic sine function;

(3) to choose the fault distance initial value be l to protective device _x, calculate apart from line protection installation place l _xThe range finding functional value f (l of point _x):

$\begin{array}{c}f\left(l_x\right)=|\mathrm{\&Delta;U}-|Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)-Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_1{l}_x\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_x\right)}\right){\stackrel{.}{I}}_0)\\ Z_{c1}\mathrm{th}\left({\mathrm{\&gamma;}}_1{l}_x\right)({\stackrel{.}{I}}_{\mathrm{\&phi;}}+\left(\frac{Z_0\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)+Z_{c0}\mathrm{sh}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)-\mathrm{ch}\left({\mathrm{\&gamma;}}_0{l}_{\mathrm{set}}\right)}{Z_{c1}\mathrm{sh}\left({\mathrm{\&gamma;}}_1{l}_{\mathrm{set}}\right)}\right){\stackrel{.}{I}}_0)\left|\right|\end{array}$

(4) fault distance increases one by one with step delta l, returns step (3), successively the range finding functional value f (l of every bit on the computing electric power line _x) until the transmission line of electricity total length, choose range finding functional value f (l _x) minimum point is fault distance apart from the distance of line protection installation place.

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