CN103163427A - Method for realizing line single-phase earth fault single-terminal fault locating by using real part of voltage drop along line - Google Patents

Abstract

The invention discloses a method for realizing line single-phase earth fault single-terminal fault locating by using a real part of voltage drop along a line. The method comprises the following steps of: calculating the real part of the voltage drop from a power transmission line protection installation part to a single-phase earth fault point by using fault phase electrical capacity, and dividing the real part of the voltage drop from the line protection installation part to the single-phase earth fault point by a real part of voltage drop of a power transmission line per unit length to obtain a fault distance. The method solves the problem that transition resistance and load current influence single-phase earth fault single-terminal fault locating accuracy; when single-phase high-resistance earth faults of the power transmission line occur, high fault locating accuracy can be achieved, the fault locating principle is simple, and the program is easy to realize; and the fault distance can be calculated under the condition that a search algorithm is not needed to be adopted; the fault locating speed is high; and strong real-time performance is guaranteed.

Description

Utilize voltage drop real part distribution character along the line 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 ofly utilize voltage drop real part distribution character along the line to realize the line single phase grounding failure method of single end distance measurement.

Background technology

In prior art, 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 synchronizer, and operating cost is low and algorithm stable, obtains widespread use in transmission line of electricity.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 precision is high, not affected by the method for operation, excessive resistance etc., but very high to the sampling rate requirement, needs special wave recording device, and application cost is high.Impedance method utilizes voltage, the magnitude of current after fault to calculate the fault loop impedance, carry out one-end fault ranging according to the characteristic that line length is directly proportional to impedance, simple and reliable, but it is serious that distance accuracy is subject to the factor impacts such as transition resistance and load current, when especially transition resistance is larger, finding range unsuccessfully even appears in impedance method range finding result meeting substantial deviation true fault distance.

Summary of the invention

The object of the invention is to overcome the deficiency that prior art exists, provide a kind of employing rate to require low, application cost is low and utilize simply, effectively, accurately voltage drop real part distribution character along the line to realize the method for single end distance measurement of line single phase grounding failure.

The objective of the invention is to realize by following approach:

Utilize voltage drop real part distribution character along the line to realize the line single phase grounding failure method of single end distance measurement, its main points are, comprise the steps:

(1) provide a kind of protective device, it includes electric measurement module, data processing module and the data outputting module that sequentially connects, and the electric measurement module is measured the fault phase voltage of line protection installation place

The fault phase negative sequence voltage The fault phase electric current

And zero-sequence current

Wherein, φ=A, B, C phase.

(2) data processing module utilizes the fault phase electric parameters of line protection installation place to calculate the line protection installation place to the voltage drop of Single-phase Ground Connection Failure

Real part

$\mathrm{Re}\left(\mathrm{\Δ}{\stackrel{\·}{U}}_f\right)=\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}$

Wherein, z ₁Be unit length transmission line of electricity positive sequence impedance; z ₀Be the impedance of unit length power transmission line zero-sequence;

Be fault phase voltage

Real part;

Be fault phase voltage

Imaginary part;

For

Imaginary part;

For

Real part;

Expression

Real part;

Expression

Imaginary part.

(3) data processing module utilizes the line protection installation place to the voltage drop of Single-phase Ground Connection Failure

Real part

Divided by the voltage drop of unit length transmission line of electricity

Real part

Obtain fault distance χ:

$\mathrm{\χ}=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0{-z}_1}{z_1})\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}}{\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}$

(4) data processing module sends by data outputting module the fault distance χ that calculates in step (3) to host computer.

The present invention has following positive achievement compared with prior art:

At first the inventive method utilizes the fault phase electric parameters to calculate the line protection installation place to the real part of the voltage drop of Single-phase Ground Connection Failure, utilizes the line protection installation place to obtain fault distance to the real part of the voltage drop of Single-phase Ground Connection Failure divided by the real part of unit length transmission line of electricity voltage drop.The inventive method has overcome transition resistance and load current to the problem that affects of singlephase earth fault single end distance measurement precision, has very high distance accuracy during the single-phase high resistance earthing fault of transmission line of electricity, range measurement principle is simple, program realizes easily, and need not to adopt searching algorithm directly to calculate fault distance, range finding speed is fast, and is real-time.

Description of drawings

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

Embodiment

The below does further statement in detail according to Figure of description to technical scheme of the present invention.

Fig. 1 is for using circuit transmission system schematic diagram of the present invention.In Fig. 1, PT is that voltage transformer (VT), CT are current transformer.Protective device inside in Fig. 1 includes electric measurement module, data processing module and the data outputting module that sequentially connects; the electric measurement module of protective device is sampled to the current waveform of the voltage waveform summation current transformer CT of the voltage transformer pt of line protection installation place and is obtained voltage, current instantaneous value, and voltage, current instantaneous value that sampling obtains is utilized the fault phase voltage of Fourier algorithm computing electric power line protection installation place

The fault phase negative sequence voltage

The fault phase electric current

And zero-sequence current

I0; Wherein, φ=A phase, B phase, C phase.

The data processing module of protective device utilizes the fault phase voltage of line protection installation place

The fault phase negative sequence voltage

The fault phase electric current

And zero-sequence current

Computing electric power line protection installation place is to the voltage drop of Single-phase Ground Connection Failure Real part

$\mathrm{Re}\left(\mathrm{\Δ}{\stackrel{\·}{U}}_f\right)=\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}$

Wherein, Be the voltage drop to Single-phase Ground Connection Failure of line protection installation place;

Real part.

Because the line protection installation place equals the real part of unit length transmission line of electricity voltage drop and the product of fault distance to the real part of Single-phase Ground Connection Failure voltage drop, namely satisfy

Therefore, the data processing module of protective device utilize the line protection installation place to the real part of the voltage drop of Single-phase Ground Connection Failure divided by the voltage drop of unit length transmission line of electricity

Real part

Obtain fault distance χ:

$\mathrm{\χ}=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0{-z}_1}{z_1})\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}}{\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}$

Wherein, z ₁Be unit length transmission line of electricity positive sequence impedance; z ₀Be the impedance of unit length power transmission line zero-sequence; Be fault phase voltage

Real part;

Be fault phase voltage

Imaginary part; For

Imaginary part;

For

Real part;

Expression

Real part;

Expression

Imaginary part.

The data processing module of protective device sends by data outputting module the fault distance χ that calculates to host computer.

At first the inventive method utilizes the fault phase electric parameters to calculate the line protection installation place to the real part of the voltage drop of Single-phase Ground Connection Failure, utilizes the line protection installation place to obtain fault distance to the real part of the voltage drop of Single-phase Ground Connection Failure divided by the real part of unit length transmission line of electricity voltage drop.The inventive method has overcome transition resistance and load current to the problem that affects of one-end fault ranging precision, has very high distance accuracy during the single-phase high resistance earthing fault of transmission line of electricity, range measurement principle is simple, program realizes easily, and need not to adopt searching algorithm directly to calculate fault distance, range finding speed is fast, and is real-time.

The above is only preferred embodiment of the present invention; but protection scope of the present invention is not limited to this; 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 are within all should being encompassed in protection scope of the present invention.

Claims (1)

1. utilize voltage drop real part distribution character along the line to realize the line single phase grounding failure method of single end distance measurement, it is characterized in that: comprise the steps:

(1) provide a kind of protective device, it includes electric measurement module, data processing module and the data outputting module that sequentially connects, and the electric measurement module is measured the fault phase voltage of line protection installation place The fault phase negative sequence voltage

The fault phase electric current

And zero-sequence current

Wherein, φ=A, B, C phase.

(2) data processing module utilizes the fault phase electric parameters of line protection installation place to calculate the line protection installation place to the voltage drop of Single-phase Ground Connection Failure

Real part

$\mathrm{Re}\left(\mathrm{\Δ}{\stackrel{\·}{U}}_f\right)=\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}$

Wherein, z ₁Be unit length transmission line of electricity positive sequence impedance; z ₀Be the impedance of unit length power transmission line zero-sequence;

Be fault phase voltage

Real part;

Be fault phase voltage Imaginary part;

For

Imaginary part;

For

Real part;

Expression Real part;

Expression

Imaginary part.

(3) data processing module utilizes the line protection installation place to the voltage drop of Single-phase Ground Connection Failure

Real part

Divided by the voltage drop of unit length transmission line of electricity Real part

Obtain fault distance χ:

$\mathrm{\χ}=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)-\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{\φ}}\right)\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}{\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)\mathrm{Im}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]-\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0{-z}_1}{z_1})\right]\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)}}{\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]}$

(4) data processing module sends by data outputting module the fault distance χ that calculates in step (3) to host computer.

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