CN103219711A - Grounding fault distance protecting method of double circuit lines on same tower - Google Patents

Abstract

The invention discloses a grounding fault distance protecting method of double circuit lines on the same tower. The grounding fault distance protecting method of the double circuit lines on the same tower comprises the steps of estimating the phase of voltages of a grounding fault point by using a fault syntropy zero sequence current phase, directly calculating a fault distance x according to the fact that the voltage drop of a protecting mounting portion to the grounding fault point is in linear relation with the fault distance, and comparing the size relationship of the fault distance x and a protection setting range xset. If a I circuit line of the double circuit lines on the same tower is in single-phase grounding fault, and the fault distance x is smaller than the protection setting range xset, the I circuit line of the double circuit lines on the same tower is protected to send an action tripping signal. If a II circuit line of the double circuit lines on the same tower is in single-phase grounding fault, and the fault distance x is smaller than the protection setting range xset, the II circuit line of the double circuit lines on the same tower is protected to send the action tripping signal. According to the grounding fault distance protecting method of the double circuit lines on the same tower, a symmetrical component method and a six-sequence component method are used comprehensively, and accurate measuring of the fault distance of the single-phase grounding fault of the single circuit line of the double circuit lines on the same tower is achieved.

Description

A kind of double-circuit lines on the same pole road earth fault distance protecting method

Technical field

The present invention relates to the relay protection of power system technical field, specifically relate to a kind of double-circuit lines on the same pole road earth fault distance protecting method.

Background technology

The additional impedance that transition resistance produces can have a strong impact on the performance of double-circuit lines on the same pole road earth fault distance protection.Earth fault distance protection tripping when if the resistance sense that is the additional impedance that transition resistance produces causes in the protection zone earth fault easily; If producing, earth fault distance protection that the additional impedance that transition resistance produces is capacitance-resistance when causing protection zone external ground fault easily surmounts.

The existence of zero-sequence mutual inductance between double-circuit lines on the same pole road direct-to-ground capacitance and line produces a very large impact the zero sequence compensation coefficient, and then the protection range of earth fault distance protection is exerted an influence, and causes protection tripping or super scope malfunction easily.Therefore, existing double-circuit lines on the same pole road earth fault distance protection can't be satisfied the requirement of electrical network.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, a kind of double-circuit lines on the same pole road earth fault distance protecting method is provided.The inventive method is taken into account the influence to double-circuit lines on the same pole road earth fault distance protection performance of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance; utilize the fault distance of the single back line single phase ground fault on single-end electrical quantity realization double-circuit lines on the same pole road accurately to measure; measurement result is not subjected to the influence of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance, is applicable to double-circuit lines on the same pole road earth fault distance protection function.

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

(1) the fault phase voltage on the I loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current

Identical with fault to zero-sequence current

Wherein, φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.The fault phase voltage on the II loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current

Identical with fault to zero-sequence current

Wherein, φ=II loop line road A phase, II loop line road B phase, II loop line road C phase.

(2) single phase ground fault takes place in the I loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3Z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}$

Wherein,

Be I loop line road fault phase voltage;

Be I loop line road fault phase current;

Be I loop line road zero-sequence current;

Be II loop line road zero-sequence current;

For I loop line road fault identical to zero-sequence current; z _I1, z _I0Be respectively unit length I loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in I loop line road; φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.

(3) single phase ground fault takes place in the II loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3Z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}$

Wherein,

Be II loop line road fault phase voltage;

Be II loop line road fault phase current; Be II loop line road zero-sequence current;

Be I loop line road zero-sequence current;

For II loop line road fault identical to zero-sequence current; z _II1, z _II0Be respectively unit length II loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in II loop line road; φ=II loop line road A phase, II loop line road B phase, II loop line road C phase.

(4) if the I loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x less than protection setting range x _Set, then the I loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal; If the II loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x are less than protection setting range x _Set, then the II loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal.

Characteristics of the present invention and technological achievement:

The inventive method is taken into account the influence to double-circuit lines on the same pole road earth fault distance protection performance of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance; utilize the fault distance of the single back line single-phase fault on single-end electrical quantity realization double-circuit lines on the same pole road accurately to measure; measurement result is not subjected to the influence of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance, is applicable to double-circuit lines on the same pole road earth fault distance protection function.

Description of drawings

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

Embodiment

Below in conjunction with embodiment the present invention is carried out more detailed description.

The fault phase voltage on the I loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current Identical with fault to zero-sequence current

Wherein, φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.The fault phase voltage on the II loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current

Identical with fault to zero-sequence current

Wherein, φ=II loop line road A phase, II loop line road B phase, II loop line road C phase.

Single phase ground fault takes place in the I loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3Z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}$

Wherein,

Be I loop line road fault phase voltage;

Be I loop line road fault phase current;

Be I loop line road zero-sequence current;

Be II loop line road zero-sequence current;

For I loop line road fault identical to zero-sequence current; z _I1, z _I0Be respectively unit length I loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in I loop line road; φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.

Single phase ground fault takes place in the II loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3Z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}$

Wherein, Be II loop line road fault phase voltage;

Be II loop line road fault phase current;

Be II loop line road zero-sequence current;

Be I loop line road zero-sequence current; For II loop line road fault identical to zero-sequence current; z _II1, z _II0Be respectively unit length II loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in II loop line road; φ=II loop line road A phase, II loop line road B phase, II loop line road C phase.

Fault distance x that protective device comparison aforementioned calculation obtains and protection setting range x _SetMagnitude relationship, if the I loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x are less than protection setting range x _Set, then the I loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal; If the II loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x are less than protection setting range x _Set, then the II loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal.

The inventive method is taken into account the influence to double-circuit lines on the same pole road earth fault distance protection performance of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance; utilize the fault distance of the single back line single-phase fault on single-end electrical quantity realization double-circuit lines on the same pole road accurately to measure; measurement result is not subjected to the influence of zero-sequence mutual inductance between line, line mutual-ground capacitor and transition resistance, is applicable to double-circuit lines on the same pole road earth fault distance protection function.

The above only is a 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. a double-circuit lines on the same pole road earth fault distance protecting method comprises the following steps:

(1) the fault phase voltage on the I loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current

Identical with fault to zero-sequence current

Wherein, φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.The fault phase voltage on the II loop line road on the double-circuit lines on the same pole road of protector measuring protection installation place

, the fault phase current

, zero-sequence current Identical with fault to zero-sequence current

Wherein, φ=II loop line road A phase, II loop line road B phase, II loop line road C phase,

(2) single phase ground fault takes place in the I loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3Z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+3{\stackrel{\·}{I}}_{I0}(\frac{z_{I0}-z_{I1}}{3z_{I1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}}+\frac{{\stackrel{\·}{I}}_{\mathrm{II}0}}{{\stackrel{\·}{I}}_{I0}}(\frac{z_{m0}}{3z_{I1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{I1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{I\φT}0}\right)}$

Wherein,

Be I loop line road fault phase voltage;

Be I loop line road fault phase current;

Be I loop line road zero-sequence current;

Be II loop line road zero-sequence current;

For I loop line road fault identical to zero-sequence current; z _I1, z _I0Be respectively unit length I loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in I loop line road; φ=I loop line road A phase, I loop line road B phase, I loop line road C phase,

(3) single phase ground fault takes place in the II loop line road on double-circuit lines on the same pole road, and the electric parameters of utilizing protection to measure is calculated fault distance:

$x=\frac{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{II\φ}}\right)\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}{\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3Z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Im}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)-\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{II\φ}}+3{\stackrel{\·}{I}}_{\mathrm{II}0}(\frac{z_{\mathrm{II}0}-z_{\mathrm{II}1}}{3z_{\mathrm{II}1}}+\frac{z_{P0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{{\stackrel{\·}{I}}_{I0}}{{\stackrel{\·}{I}}_{\mathrm{II}0}}(\frac{z_{m0}}{3z_{\mathrm{II}1}}+\frac{z_{M0}{Y}_{b0}}{2}\frac{z_{m0}}{3z_{\mathrm{II}1}})))\mathrm{Re}\left({\stackrel{\·}{I}}_{\mathrm{II\φT}0}\right)}$

Wherein,

Be II loop line road fault phase voltage;

Be II loop line road fault phase current; Be II loop line road zero-sequence current;

Be I loop line road zero-sequence current; For II loop line road fault identical to zero-sequence current; z _II1, z _II0Be respectively unit length II loop line road positive sequence, zero sequence impedance; z _M0Be zero-sequence mutual inductance between the line on I loop line road and II loop line road; z _M0II loop line road system zero sequence equivalent impedance for the protection installation place; z _P0I loop line road system zero sequence equivalent impedance for the protection installation place; Y _B0Be the total zero sequence admittance in II loop line road; φ=II loop line road A phase, II loop line road B phase, II loop line road C phase,

(4) if the I loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x less than protection setting range x _Set, then the I loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal; If the II loop line road single phase ground fault on double-circuit lines on the same pole road and fault distance x are less than protection setting range x _Set, then the II loop line road on double-circuit lines on the same pole road is protected and is started to do trip signal.