CN103762560B - The non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line - Google Patents

Abstract

The invention discloses a kind of non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line, first it measure double-circuit line I and return the faulted phase voltage of route protection installation place, faulted phase current and zero-sequence current, calculate the zero-sequence current on double-circuit line II loop line road, utilize the phase angle estimation I loop line road earth fault voltage phase angle of I loop line road zero-sequence current and II loop line road zero-sequence current sum, then judge that the phase corner of voltage leading I loop line road earth fault point voltage at the protection seting scope of I loop line road is at [165 °, 15 °] in the range of whether set up, if setting up, then protection device sends action trip signal.The inventive method only uses single-ended single back line electric parameters; performance is not affected by power system operation mode; eliminating the impact on double-circuit lines on the same pole Lu Feitong famous prime minister's cross-line earthing reactance distance relay performance of zero-sequence mutual inductance between line, transition resistance and load current, protection domain is reliable and stable.

Description

The non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line

Technical field

The present invention relates to a kind of Force system technical field of relay protection, concretely relate to a kind of double-circuit line non-of the same name Phase cross-line earthing reactance distance protecting method.

Background technology

Double-circuit lines on the same pole road has that floor space is few, cost is low, connects operation of power networks reliable and stable, it has also become A kind of common transmission line of electricity connected mode of power system.Zero-sequence mutual inductance, zero-sequence mutual inductance pair is there is between double-circuit lines on the same pole route Zero-utility theory produces impact, and then produces additional impedance, and the additional impedance caused because of zero-sequence mutual inductance can cause protection device Measure the fault impedance arrived and be more than physical fault impedance, close protection seting scope in causing protection zone, double-circuit lines on the same pole road When place occurs earth fault, there is misoperation in protection, unfavorable to power network safety operation.

Even if double-circuit lines on the same pole road occurs to be directly grounded fault through shaft tower, in soil resistivity lower ground district's transition Resistance is also near 10 Ω；The local transition resistance higher in resistivity is up to 30 Ω or the highest.Transition resistance is not zero Make the calculated fault impedance of protection device in addition to comprising the fault impedance component of reaction true fault distance, further comprises The additional impedance produced because of transition resistance.The additional impedance that transition resistance produces is that resistance sense or easily cause in capacitance-resistance connects Ground impedance distance protection tripping or steady-state.Protective relaying maloperation or tripping, can bring great to safe operation of power system Loss, it could even be possible to the stability of power system can be threatened.

Summary of the invention

The invention provides a kind of non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line, which overcome background The deficiencies in the prior art described in technology.

The present invention solves being the technical scheme is that of its technical problem

The non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line, it is characterised in that include following sequential steps:

Step 1, protector measuring double-circuit lines on the same pole road I returns the faulted phase voltage of route protection installation place Faulted phase currentAnd zero-sequence currentWherein: φ is I loop line road A phase, I loop line road B phase, I loop line road C phase；

Step 2, protection device calculates the zero-sequence current phase angle α=r on II loop line road, double-circuit lines on the same pole road₁+r₂-π-β；

Wherein: $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),a_3=b_3=\left|\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right|,\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right);$ Z_mFor 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；Z_I0For parallel lines on same tower The zero sequence impedance on double-circuit line I loop line road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ=I loop line road A Phase, I loop line road B phase, I loop line road C phase；

Step 3, protection device calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road ${\stackrel{\·}{I}}_{\mathrm{II}0}={\stackrel{\·}{I}}_{I0}(\cos \mathrm{\α}+j\sin \mathrm{\α});$

Step 4, protection device calculates ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ LeadingPhase corner Whether set up in the range of [-165 °, 15 °], if setting up, then protection device sends action trip signal；Wherein: l_setFor same bar And frame double-circuit line I loop line road protection seting scope, l is that double-circuit lines on the same pole road I returns line length.

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, fault Phase current and zero-sequence current, calculate the zero-sequence current phase angle on II loop line road, double-circuit lines on the same pole road, calculates parallel lines on same tower double back The zero-sequence current on circuit II loop line road, utilizes double-circuit lines on the same pole road I loop line road zero-sequence current and double-circuit lines on the same pole road The phase angle estimation I loop line road earth fault voltage phase angle of II loop line road zero-sequence current sum, calculates I loop line road protection seting model Enclose the voltage at place, then judge the phase angle of voltage leading I loop line road earth fault point voltage at the protection seting scope of I loop line road Whether fall and set up in the range of [-165 °, 15 °], if setting up, then protection device sends action trip signal.The inventive method is only Use single-ended single back line electric parameters, it is not necessary to introducing another loop line road electric parameters, performance is not by Operation of Electric Systems side The impact of formula, has the strongest adaptation ability when power system operation mode occurs bigger change.The inventive method meter and line Between zero-sequence mutual inductance and the impact of earth fault point voltage, eliminate zero-sequence mutual inductance between line, transition resistance and load current to same bar And the impact of the non-same famous prime minister's cross-line earthing reactance distance protection performance of frame double-circuit line, protection domain is reliable and stable.

Accompanying drawing explanation

The invention will be further described with embodiment below in conjunction with the accompanying drawings.

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

Refer to Fig. 1, in Fig. 1 PT be voltage transformer 2, CT be current transformer 3.Transmission line of electricity is protected by protection device 1 Protect the current waveform that the voltage waveform summation current transformer 3 that the voltage transformer 2 of installation place obtained obtained to adopt respectively Sample obtains voltage, current instantaneous value.

Voltage, current instantaneous value that sampling is obtained by protection device 1 utilize Fourier algorithm to calculate double-circuit lines on the same pole Road I returns the faulted phase voltage of route protection installation placeFaulted phase currentAnd zero-sequence currentWherein, φ=I loop line road A phase, I loop line road B phase, I loop line road C phase.

And then, protection device 1 calculates the zero-sequence current phase angle α=r on II loop line road, double-circuit lines on the same pole road₁+r₂-π-β；

Wherein: $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),a_3=b_3=\left|\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right|,\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right);$ Z_mFor 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；Z_I0For parallel lines on same tower The zero sequence impedance on double-circuit line I loop line road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ=I loop line road A Phase, I loop line road B phase, I loop line road C phase；

And then, protection device 1 calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road ${\stackrel{\·}{I}}_{\mathrm{II}0}={\stackrel{\·}{I}}_{I0}(\cos \mathrm{\α}+j\sin \mathrm{\α});$

Finally, protection device 1 calculates ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ LeadingPhase corner Whether set up in the range of [-165 °, 15 °], if setting up, then protection device sends action trip signal；Wherein: l_setFor same bar And frame double-circuit line I loop line road protection seting scope, l is that double-circuit lines on the same pole road I returns line length.

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, fault Phase current and zero-sequence current, calculate the zero-sequence current phase angle on II loop line road, double-circuit lines on the same pole road, calculates parallel lines on same tower double back The zero-sequence current on circuit II loop line road, utilizes double-circuit lines on the same pole road I loop line road zero-sequence current and double-circuit lines on the same pole road The phase angle estimation I loop line road earth fault voltage phase angle of II loop line road zero-sequence current sum, then judges that I returns route protection whole Whether the phase corner determining the leading I loop line of voltage at scope road earth fault point voltage sets up in the range of [-165 ° 15 °], if becoming Vertical, then protection device sends action trip signal.The inventive method only uses single-ended single back line electric parameters, it is not necessary to introduce another One loop line road electric parameters, performance is not affected by power system operation mode, occurs bigger at power system operation mode There is during change the strongest adaptation ability.Between the inventive method meter and line, zero-sequence mutual inductance and the impact of earth fault point voltage, disappear Except between line zero-sequence mutual inductance, transition resistance and load current to double-circuit lines on the same pole Lu Feitong famous prime minister's cross-line earthing reactance distance The impact of actuating of relay performance, protection domain is reliable and stable.

The above, only present pre-ferred embodiments, therefore the scope that the present invention implements can not be limited according to this, i.e. depend on The equivalence change that the scope of the claims of the present invention and description are made with modify, all should still belong in the range of the present invention contains.

Claims (1)

1. the non-same famous prime minister's cross-line earthing reactance distance protecting method of double-circuit line, it is characterised in that include following sequential steps:

Step 1, protector measuring double-circuit lines on the same pole road I returns the faulted phase voltage of route protection installation placeFault phase Electric currentAnd zero-sequence currentWherein: φ is I loop line road A phase, I loop line road B phase, I loop line road C phase；

Step 2, protection device calculates the zero-sequence current phase angle α=r on II loop line road, double-circuit lines on the same pole road₁+r₂-π-β；

Wherein: $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),a_3=b_3=\left|\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right|,\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right);$ Z_mFor 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；Z_I0For parallel lines on same tower The zero sequence impedance on double-circuit line I loop line road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ=I loop line road A Phase, I loop line road B phase, I loop line road C phase；

Step 3, protection device calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road ${\stackrel{\·}{I}}_{\mathrm{II}0}={\stackrel{\·}{I}}_{I0}(\cos \mathrm{\α}+j\sin \mathrm{\α});$

Step 4, protection device calculates ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ LeadingPhase corner [- 165 °, 15 °] in the range of whether set up, if setting up, then protection device sends action trip signal；Wherein: l_setFor parallel lines on same tower Double-circuit line I loop line road protection seting scope, l is that double-circuit lines on the same pole road I returns line length.