CN103163427B - 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 and realize line single-phase earth fault single-terminal location method along line drop real part distribution character

Technical field

The present invention relates to electric system one-end fault ranging technical field, specifically relate to a kind of utilization and realize line single-phase earth fault single-terminal location method along line drop real part distribution character.

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 syn-chronization equipment, and the low and algorithmic stability of operating cost, obtains widespread use in transmission line of electricity.Method of single end distance measurement is mainly 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, does not affect by the method for operation, excessive resistance etc., but requires very high to sampling rate, and need special wave recording device, application cost is high.Impedance method utilizes the voltage after fault, the magnitude of current to calculate Fault loop impedance, one-end fault ranging is carried out 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 impact of the factor such as transition resistance and load current, especially when transition resistance is larger, finding range unsuccessfully, even appear in impedance method range measurement 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 simple, effectively, utilize the method for single end distance measurement realizing line single phase grounding failure along line drop real part distribution character accurately.

The object of the invention is to be realized by following approach:

Utilize and realize line single-phase earth fault single-terminal location method along line drop real part distribution character, its main points are, comprise the steps:

(1) provide a kind of protective device, it includes the electric measurement module, data processing module and the data outputting module that sequentially connect, and electric measurement module measures the faulted phase voltage of line protection installation place fault phase negative sequence voltage faulted phase 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 voltage drop of line protection installation place to 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 ₁for unit length electric transmission line positive sequence impedance; z ₀for unit length power transmission line zero-sequence impedance; for faulted phase voltage real part; for faulted phase voltage imaginary part; for imaginary part; for real part; represent real part; represent imaginary part.

(3) data processing module utilizes 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 calculated in step (3) to host computer.

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

First the inventive method utilizes fault phase electric parameters to calculate line protection installation place to the real part of the voltage drop of Single-phase Ground Connection Failure, utilizes 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 present invention overcomes transition resistance and load current and problem is affected on singlephase earth fault single end distance measurement precision, there is during transmission line of electricity single-phase high-impedance very high distance accuracy, range measurement principle is simple, program realizes easily, and without the need to adopting searching algorithm directly to calculate fault distance, range finding speed is fast, real-time.

Accompanying drawing explanation

Fig. 1 is application multi-line power transmission system schematic of the present invention.

Embodiment

According to Figure of description, technical scheme of the present invention is expressed in further detail below.

Fig. 1 is application multi-line power transmission system schematic of the present invention.In Fig. 1, PT is voltage transformer (VT), CT is current transformer.Protective device inside in Fig. 1 includes the electric measurement module, data processing module and the data outputting module that sequentially connect; the current waveform of electric measurement module to the voltage waveform summation current transformer CT of the voltage transformer pt of line protection installation place of protective device carries out sampling and obtains voltage, current instantaneous value, and the voltage obtained sampling, current instantaneous value utilize Fourier algorithm computing electric power line to protect the faulted phase voltage of installation place fault phase negative sequence voltage faulted phase current and zero-sequence current i0; Wherein, φ=A phase, B phase, C phase.

The data processing module of protective device utilizes the faulted phase voltage of line protection installation place fault phase negative sequence voltage faulted phase 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, for line protection installation place is to the voltage drop of Single-phase Ground Connection Failure; real part.

Because 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 meet therefore, the data processing module of protective device utilizes 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 ₁for unit length electric transmission line positive sequence impedance; z ₀for unit length power transmission line zero-sequence impedance; for faulted phase voltage real part; for faulted phase voltage imaginary part; for imaginary part; for real part; represent real part; represent imaginary part.

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

First the inventive method utilizes fault phase electric parameters to calculate line protection installation place to the real part of the voltage drop of Single-phase Ground Connection Failure, utilizes 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 present invention overcomes transition resistance and load current and problem is affected on one-end fault ranging precision, there is during transmission line of electricity single-phase high-impedance very high distance accuracy, range measurement principle is simple, program realizes easily, and without the need to adopting searching algorithm directly to calculate fault distance, range finding speed is fast, real-time.

The foregoing is only 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 change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1. utilize and realize line single-phase earth fault single-terminal location method along line drop real part distribution character, it is characterized in that: comprise the steps:

(1) provide a kind of protective device, it includes the electric measurement module, data processing module and the data outputting module that sequentially connect, and electric measurement module measures the faulted phase voltage of line protection installation place fault phase negative sequence voltage faulted phase 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 voltage drop of line protection installation place to Single-phase Ground Connection Failure real part

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

Wherein, z ₁for unit length electric transmission line positive sequence impedance; z ₀for unit length power transmission line zero-sequence impedance; for faulted phase voltage real part; for faulted phase voltage imaginary part; for $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Imaginary part; ${\mathrm{Re}[z}_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)]$ For $z_1({\stackrel{\·}{I}}_{\mathrm{\φ}}+\frac{z_0-z_1}{z_1}{\stackrel{\·}{I}}_0)$ Real part; $\mathrm{Re}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)$ Represent $-\frac{{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Real part; $\mathrm{Im}\left(\frac{-{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}\right)$ Represent $-\frac{{\stackrel{\·}{U}}_{\mathrm{\φ}2}}{z_1}$ Imaginary part;

(3) data processing module utilizes 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:

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

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