CN103245890A - Line single-phase ground fault single-terminal location method capable of preventing influences of both transitional resistance and load current - Google Patents

Abstract

The invention discloses a line single-phase ground fault single-terminal location method capable of preventing influences of both transitional resistance and load current. According to the method, the voltage phase angle of a single-phase ground fault point is calculated by utilizing the fault-phase negative sequence voltage of the relay location of a transmission line and the positive sequence impedance of the transmission line per unit length; the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is calculated according to the characteristic that the voltage along the transmission line is in linear monotone decreasing; and the imaginary part of the voltage drop from the relay location of the transmission line to the single-phase ground fault point is divided by the imaginary part of the voltage drop of the transmission line per unit length to obtain the fault location. The line single-phase ground fault single-terminal location method solves the problem that the transitional resistance and the load current influence the single-terminal fault location precision, is high in single-terminal location precision, simple in location principle and easy in program implementation, and does not need to adopt the search algorithm, so that direct calculation of the fault location is realized, location speed is quick and the real-time performance is strong.

Description

The line single phase grounding failure method of single end distance measurement of anti-transition resistance and load current influence

Technical field

The present invention relates to electric system one-end fault ranging technical field, specifically relate to the line single phase grounding failure method of single end distance measurement of a kind of anti-transition resistance and load current influence.

Background technology

One-end fault ranging method 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 transmission line of electricity.One-end fault ranging method 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 power system operation mode, 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.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, the line single phase grounding failure method of single end distance measurement of a kind of anti-transition resistance and load current influence is provided.

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

The line single phase grounding failure method of single end distance measurement of anti-transition resistance and load current influence, its main points are, comprise the steps:

(1) provide a kind of protective device, it includes data acquisition system (DAS) and data handling system, and wherein the fault phase voltage of line protection installation place is measured and obtained to data acquisition system (DAS) Fault phase negative sequence voltage

The fault phase current

And zero-sequence current

Wherein, φ=A, B, C phase;

(2) data acquisition system (DAS) sends the fault phase electric parameters of its line protection installation place that measures the data handling system of protective device to, and data handling system utilizes the fault phase electric parameters of its line protection installation place that receives to calculate the line protection installation place to the fault distance χ of singlephase earth fault point:

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

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

Be the fault phase voltage

Real part;

Be the fault phase voltage

Imaginary part;

For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Imaginary part; $\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]$ For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Real part; $\mathrm{Re}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Real part; $\mathrm{Im}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Imaginary part.

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

The inventive method utilizes line protection installation place fault phase negative sequence voltage and unit length transmission line of electricity positive sequence impedance to calculate singlephase earth fault point voltage phase angle; be linear monotonic decline characteristic computing electric power line protection installation place to the imaginary part of the voltage drop of singlephase earth fault point according to transmission line of electricity voltage along the line, utilize the line protection installation place to obtain fault distance to the imaginary part of the voltage drop of singlephase earth fault point divided by the imaginary part of unit length transmission line of electricity voltage drop.This method has overcome transition resistance and load current to the problem that influences of one-end fault ranging precision, one-end fault ranging precision height, and 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 synoptic diagram of the present invention.

Embodiment

According to Figure of description technical scheme of the present invention is done further detailed presentations below.

Fig. 1 is for using circuit transmission system synoptic diagram of the present invention.PT is that voltage transformer (VT), CT are current transformer among Fig. 1.The data acquisition system (DAS) of protective device is sampled to the current waveform of the voltage and current mutual inductor CT of the voltage transformer pt of line protection installation place and is obtained voltage, current instantaneous value.

The voltage that the data acquisition system (DAS) of protective device obtains its sampling, current instantaneous value are protected the fault phase voltage of installation place by the Fourier algorithm computing electric power line Fault phase negative sequence voltage

The fault phase current

And zero-sequence current As input quantity; Wherein, φ=A phase, B phase, C phase.

The data acquisition system (DAS) of protective device is with the fault phase voltage of line protection installation place

Fault phase negative sequence voltage The fault phase current

And zero-sequence current

Calculated value send the data handling system of protective device to, the data handling system of protective device utilizes the fault phase electric parameters of its line protection installation place that receives to calculate the line protection installation place to the voltage drop of singlephase earth fault point

Imaginary part

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

Wherein,

Be the voltage drop of line protection installation place to singlephase earth fault point;

Imaginary part.

Utilize the line protection installation place to obtain fault distance χ to the imaginary part of the voltage drop of singlephase earth fault point divided by the imaginary part of unit length transmission line of electricity voltage drop:

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

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

Be the fault phase voltage

Real part; Be the fault phase voltage

Imaginary part;

For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Imaginary part; $\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]$ For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Real part; $\mathrm{Re}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Real part; $\mathrm{Im}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Imaginary part.

The inventive method utilizes line protection installation place fault phase negative sequence voltage and unit length transmission line of electricity positive sequence impedance to calculate singlephase earth fault point voltage phase angle; be linear monotonic decline characteristic computing electric power line protection installation place to the imaginary part of the voltage drop of singlephase earth fault point according to transmission line of electricity voltage along the line, utilize the line protection installation place to obtain fault distance to the imaginary part of the voltage drop of singlephase earth fault point divided by the imaginary part of unit length transmission line of electricity voltage drop.This method has overcome transition resistance and load current to the problem that influences of one-end fault ranging precision, one-end fault ranging precision height, and 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 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. the line single phase grounding failure method of single end distance measurement of anti-transition resistance and load current influence is characterized in that, comprises the steps:

(1) provide a kind of protective device, it includes data acquisition system (DAS) and data handling system, and wherein the fault phase voltage of line protection installation place is measured and obtained to data acquisition system (DAS)

Fault phase negative sequence voltage

The fault phase current

And zero-sequence current

Wherein, φ=A, B, C phase;

(2) data acquisition system (DAS) sends the fault phase electric parameters of its line protection installation place that measures the data handling system of protective device to, and data handling system utilizes the fault phase electric parameters of its line protection installation place that receives to calculate the line protection installation place to the fault distance χ of singlephase earth fault point:

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

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

Be the fault phase voltage

Real part;

Be the fault phase voltage

Imaginary part;

For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Imaginary part; $\mathrm{Re}\left[z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)\right]$ For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Real part; $\mathrm{Re}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Real part; $\mathrm{Im}\left[\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right]$ Expression $\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Imaginary part.

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