CN104062553B - Double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement - Google Patents

Abstract

The invention discloses a kind of double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement.First the inventive method is measured double-circuit lines on the same pole road I and is returned the fault phase electric parameters of route protection installation place and calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road; then linear search method is adopted; going back to route protection installation place from double-circuit lines on the same pole road I; it is incremented by successively with fixed step size; calculate the single-ended position error of every bit on I loop line road, double-circuit lines on the same pole road successively; until double-circuit lines on the same pole road I returns total track length, choosing the minimum point of single-ended position error is trouble point.The inventive method takes into account the impact of zero-sequence mutual inductance between line, eliminates the zero-sequence mutual inductance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision between line；And the impact of consideration Single-phase Ground Connection Failure voltage in algorithm model, eliminate the transition resistance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision, there is significantly high range accuracy.

Description

Double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement

Technical field

The present invention relates to Relay Protection Technology in Power System field, concretely relate to the double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement of zero-sequence mutual inductance and transition resistance impact between a kind of anti-line.

Background technology

Dividing from range finding electric parameters used, the method for fault localization can be divided into two big classes: both-end distance measuring and single end distance measurement.Two-terminal Fault Location method is the method utilizing transmission line of electricity two ends electric parameters to determine transmission line malfunction position, and it requires over passage and obtains opposite end electric parameters, therefore that the dependency of passage is strong, is also subject to the impact of both-end sampling value synchronization in actually used.Single end distance measurement method is a kind of method that the voltage x current data merely with transmission line of electricity one end determine transmission line malfunction position, an end data is only needed due to it, without communication and data synchronizer, operating cost is low and algorithmic stability, therefore obtains in mid & low-voltage line and applies widely.At present, method of single end distance measurement is broadly divided into two classes, and a class is traveling wave method, another kind of for impedance method.Traveling wave method utilizes the transmission character of fault transient travelling wave to find range, and precision is high, is not affected by the method for operation, excessive resistance etc., but requires significantly high to sample rate, it is necessary to special wave recording device, does not obtain substantial application at present.Impedance method utilizes the voltage after fault, the magnitude of current to calculate the impedance of fault loop, find range according to the characteristic that line length is directly proportional to impedance, range measurement principle is simple and reliable, but when being applied to double-circuit lines on the same pole road singlephase earth fault one-end fault ranging, range accuracy is subject between trouble point transition resistance and line zero-sequence mutual inductance, and impact is serious.There is zero-sequence mutual inductance between double-circuit lines on the same pole route, zero-utility theory can be produced impact by zero-sequence mutual inductance, and then causes impedance method range measurement bigger error.If there is single-phase high-impedance in double-circuit lines on the same pole road, by zero-sequence mutual inductance between line and high transition resistance combined influence, impedance method range measurement is usually beyond total track length or without range measurement, fault location information accurately cannot be provided, cause line fault line walking difficulty, be unfavorable for that fault quickly discharges quick-recovery fast with line powering.

Summary of the invention

It is an object of the invention to the deficiency overcoming prior art to exist, it is provided that the double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement of zero-sequence mutual inductance and transition resistance impact between a kind of anti-line.

This invention address that being the technical scheme is that of its technical problem

Double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement, it includes following sequential steps:

(1) protector measuring double-circuit lines on the same pole road I returns the faulted phase voltage of route protection installation placeFaulted phase currentFault phase negative-sequence currentAnd zero-sequence currentWherein, φ is I loop line road A phase, I loop line road B phase or I loop line road C phase；

(2) protection device chooses fault distance initial value is l_x, calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road

${\stackrel{\·}{I}}_{II0}=\frac{(l_x{Z}_{n0}-(l-l_x\left)Z_{m0}\right){\stackrel{\·}{I}}_{I0}}{(2l-l_x)Z_{n0}+(l-l_x)(Z_{m0}+Z_{I0}+Z_m)}$

Wherein, Z_m0Zero sequence system equivalent impedance for this protection installation place, side, I loop line road, double-circuit lines on the same pole road；Z_n0The zero sequence system equivalent impedance of installation place is protected for I loop line road, double-circuit lines on the same pole road offside；Z_mFor the zero-sequence mutual inductance between I loop line road, double-circuit lines on the same pole road and II loop line road, double-circuit lines on the same pole road；L is that double-circuit lines on the same pole road I returns line length；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；

(3) calculate double-circuit lines on the same pole road I and return route protection installation place l_xThe single-ended position error ε (l of point_x):

$\mathrm{\ϵ}\left(l_x\right)=\left|\frac{\mathrm{Im}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}{\mathrm{Re}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}-\frac{\mathrm{Im}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}{\mathrm{Re}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}\right|$

Wherein, Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；ForReal part；ForImaginary part；ForReal part；ForImaginary part；

(4) fault distance initial value l_xGradually increase with step delta l, return step (2), calculate the single-ended position error ε (l of every bit on I loop line road, double-circuit lines on the same pole road successively_x), until double-circuit lines on the same pole road I returns total track length, choose single-ended position error ε (l_x) minimum point is trouble point.

The technical program is compared with background technology, and it has the advantage that

First the inventive method is measured double-circuit lines on the same pole road I and is returned the faulted phase voltage of route protection installation place, faulted phase current, fault phase negative-sequence current and zero-sequence current, the I fault phase electric parameters going back to route protection installation place in double-circuit lines on the same pole road is utilized to calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road, then linear search method is adopted, going back to route protection installation place from double-circuit lines on the same pole road I, it is incremented by successively with fixed step size, calculate the single-ended position error of every bit on I loop line road, double-circuit lines on the same pole road successively, until double-circuit lines on the same pole road I returns total track length, choose single-ended position error ε (l_x) minimum point is trouble point.The inventive method takes into account the impact of zero-sequence mutual inductance between line, eliminates the zero-sequence mutual inductance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision between line；The inventive method algorithm model considers the impact of Single-phase Ground Connection Failure voltage, eliminates the transition resistance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision, there is significantly high range accuracy.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described.

Fig. 1 is the double-circuit lines on the same pole road transmission system schematic diagram of the application present invention.

Detailed description of the invention

Fig. 1 is the double-circuit lines on the same pole road transmission system schematic diagram of the application present invention.In Fig. 1, PT is voltage transformer；CT is current transformer.Protector measuring double-circuit lines on the same pole road I returns the faulted phase voltage of route protection installation placeFaulted phase currentFault phase negative-sequence currentAnd zero-sequence currentWherein, φ is I loop line road A phase, I loop line road B phase or I loop line road C phase.

It is l that protection device chooses fault distance initial value_x, calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road

${\stackrel{\·}{I}}_{II0}=\frac{(l_x{Z}_{n0}-(l-l_x\left)Z_{m0}\right){\stackrel{\·}{I}}_{I0}}{(2l-l_x)Z_{n0}+(l-l_x)(Z_{m0}+Z_{I0}+Z_m)}---\left(1\right)$

Wherein, Z_m0Zero sequence system equivalent impedance for this protection installation place, side, I loop line road, double-circuit lines on the same pole road；Z_n0The zero sequence system equivalent impedance of installation place is protected for I loop line road, double-circuit lines on the same pole road offside；Z_mFor the zero-sequence mutual inductance between I loop line road, double-circuit lines on the same pole road and II loop line road, double-circuit lines on the same pole road；L is that double-circuit lines on the same pole road I returns line length；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road.

Calculate double-circuit lines on the same pole road I and return route protection installation place l_xThe single-ended position error ε (l of point_x):

$\mathrm{\ϵ}\left(l_x\right)=\left|\frac{\mathrm{Im}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}{\mathrm{Re}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}-\frac{\mathrm{Im}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}{\mathrm{Re}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}\right|---\left(2\right)$

Wherein, Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；Z_mFor the zero-sequence mutual inductance between I loop line road, double-circuit lines on the same pole road and II loop line road, double-circuit lines on the same pole road；L is that double-circuit lines on the same pole road I returns line length；ForReal part；ForImaginary part；ForReal part；ForImaginary part.

Fault distance initial value l_xGradually increase with step delta l, recycle formula (1) and formula (2) calculates the single-ended position error ε (l of every bit on I loop line road, double-circuit lines on the same pole road successively_x), until double-circuit lines on the same pole road I returns total track length, choose single-ended position error ε (l_x) minimum point is trouble point.

First the inventive method is measured double-circuit lines on the same pole road I and is returned the faulted phase voltage of route protection installation place, faulted phase current, fault phase negative-sequence current and zero-sequence current, the I fault phase electric parameters going back to route protection installation place in double-circuit lines on the same pole road is utilized to calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road, then linear search method is adopted, going back to route protection installation place from double-circuit lines on the same pole road I, it is incremented by successively with fixed step size, calculate the single-ended position error of every bit on I loop line road, double-circuit lines on the same pole road successively, until double-circuit lines on the same pole road I returns total track length, choose single-ended position error ε (l_x) minimum point is trouble point.The inventive method takes into account the impact of zero-sequence mutual inductance between line, eliminates the zero-sequence mutual inductance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision between line；The inventive method algorithm model considers the impact of Single-phase Ground Connection Failure voltage, eliminates the transition resistance impact on double-circuit lines on the same pole road singlephase earth fault single end distance measurement precision, there is significantly high range accuracy.

The above, be only present pre-ferred embodiments, therefore can not limit scope of the invention process according to this, and the equivalence namely made according to the scope of the claims of the present invention and description changes and modifies, and all should still belong in the scope that the present invention contains.

Claims (1)

1. double-circuit lines on the same pole road singlephase earth fault method of single end distance measurement, it is characterised in that: include following sequential steps:

(1) protector measuring double-circuit lines on the same pole road I returns the faulted phase voltage of route protection installation placeFaulted phase currentFault phase negative-sequence currentAnd zero-sequence currentWherein, φ is I loop line road A phase, I loop line road B phase or I loop line road C phase；

(2) protection device chooses fault distance initial value is l_x, calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road

${\stackrel{\·}{I}}_{II0}=\frac{(l_x{Z}_{n0}-(l-l_x\left)Z_{m0}\right){\stackrel{\·}{I}}_{I0}}{(2l-l_x)Z_{n0}+(l-l_x)(Z_{m0}+Z_{I0}+Z_m)}$

Wherein, Z_m0Zero sequence system equivalent impedance for this protection installation place, side, I loop line road, double-circuit lines on the same pole road；Z_n0The zero sequence system equivalent impedance of installation place is protected for I loop line road, double-circuit lines on the same pole road offside；Z_mFor the zero-sequence mutual inductance between I loop line road, double-circuit lines on the same pole road and II loop line road, double-circuit lines on the same pole road；L is that double-circuit lines on the same pole road I returns line length；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；

(3) calculate double-circuit lines on the same pole road I and return route protection installation place l_xThe single-ended position error ε (l of point_x):

$\mathrm{\ϵ}\left(l_x\right)=|\frac{\mathrm{Im}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}{\mathrm{Re}\left({\stackrel{\·}{I}}_{I\mathrm{\φ}2}\right)}-\frac{\mathrm{Im}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}{\mathrm{Re}({\stackrel{\·}{U}}_{I\mathrm{\φ}}-\frac{Z_{I1}{l}_x}{l}({\stackrel{\·}{I}}_{I\mathrm{\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{II0}\left)\right)}|$

Wherein, Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；ForImaginary part；ForReal part；ForReal part；ForImaginary part；

(4) fault distance initial value l_xGradually increase with step delta l, return step (2), calculate the single-ended position error ε (l of every bit on I loop line road, double-circuit lines on the same pole road successively_x), until double-circuit lines on the same pole road I returns total track length, choose single-ended position error ε (l_x) minimum point is trouble point.