CN103762574B - The non-same famous prime minister's cross-line impedance ground distance protecting method of double-circuit line - Google Patents

Abstract

The invention discloses a kind of non-same famous prime minister's cross-line impedance ground distance protecting method of double-circuit line.First measure double-circuit lines on the same pole road I and return the faulted phase voltage of route protection installation place, faulted 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; calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road; then calculate double-circuit lines on the same pole road I and return the line fault impedance to earth fault of the route protection installation place; judge that whether line fault impedance magnitude is less than impedance magnitude of adjusting; if less than, then send trip signal.This method only uses single-ended single back line electric parameters, it is not necessary to introduce another loop line road electric parameters, and performance is not by the impact of power system operation mode.This method takes into account the impact of zero-sequence mutual inductance and earth fault point voltage between line, eliminates the impact on double-circuit lines on the same pole Lu Feitong famous prime minister's cross-line impedance ground distance protection performance of zero-sequence mutual inductance between line, transition resistance and load current.

Description

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

Technical field

The present invention relates to Relay Protection Technology in Power System field, concretely relate to a kind of non-same famous prime minister's cross-line impedance ground distance protecting method of double-circuit line.

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 is there is between double-circuit lines on the same pole route; zero-utility theory is produced impact by zero-sequence mutual inductance; and then generation additional impedance; the fault impedance that the additional impedance caused because of zero-sequence mutual inductance can cause protector measuring to arrive is more than physical fault impedance; when causing close protection seting scope place generation earth fault in protection zone, double-circuit lines on the same pole road; there is refused action in protection, and power network safety operation is unfavorable.

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

Summary of the invention

It is an object of the invention to the deficiency overcoming prior art to exist, it is provided that a kind of performance is not affected by zero-sequence mutual inductance, transition resistance and load current between line, it is adaptable to the impedance ground distance method of the non-same famous prime minister's cross-line earth fault of double-circuit line.

For completing above-mentioned purpose, the present invention adopts the following technical scheme that

The non-same famous prime minister's cross-line impedance ground distance protecting method of double-circuit line, 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 currentAnd zero-sequence currentWherein, φ is I loop line road A phase or I loop line road B phase or I loop line road C phase；

(2) protection device calculates the zero-sequence current phase angle α on II loop line road, double-circuit lines on the same pole road:

α=r₁+r₂-π-β

Wherein, $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);$ $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});a_3=b_3=\left|\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right|;$ $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right);$

Z_mFor 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；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole 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；

(3) protection device calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road

(4) protection device calculates double-circuit lines on the same pole road I and returns the route protection installation place line fault impedance Z to earth fault_φ:

$Z_{\mathrm{\φ}}=\frac{\{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\}{Z}_{I1}}{\mathrm{Re}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\mathrm{Im}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)}$

Wherein, Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ is loop line road A phase or I loop line road B phase or I loop line road C phase；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；

(5) protection device judgesWhether setting up, if setting up, then judging that earth fault is positioned at I loop line road, double-circuit lines on the same pole road protection seting scope, protection device sends action trip signal；Wherein, l_setFor I loop line road, double-circuit lines on the same pole road protection seting scope；L is that double-circuit lines on the same pole road I returns line length.

The feature of the present invention and technological achievement:

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 and zero-sequence current; calculate the zero-sequence current phase angle on II loop line road, double-circuit lines on the same pole road; calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road; then calculate double-circuit lines on the same pole road I and return the line fault impedance to earth fault of the route protection installation place; judge line fault impedance magnitude less than whether impedance magnitude of adjusting is set up; if setting up, then send action trip signal.

The inventive method only uses single-ended single back line electric parameters, it is not necessary to introduce another loop line road electric parameters, and performance, not by the impact of power system operation mode, has very strong adaptive capacity when bigger change occurs power system operation mode.The inventive method takes into account the impact of zero-sequence mutual inductance and earth fault point voltage between line; eliminating the impact on double-circuit lines on the same pole Lu Feitong famous prime minister's cross-line impedance ground distance protection performance of zero-sequence mutual inductance between line, transition resistance and load current, protection domain is reliable and stable.

Accompanying drawing explanation

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

Hereafter by the present invention will be further described in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the double-circuit lines on the same pole road transmission system schematic diagram of the application present invention.Protector measuring 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 is I loop line road A phase or I loop line road B phase or I loop line road C phase.

Protection device calculates the zero-sequence current phase angle α on II loop line road, double-circuit lines on the same pole road:

α=r₁+r₂-π-β

Wherein, $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);$ $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});a_3=b_3=\left|\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right|;$ $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right);$

Z_mFor 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；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ is I loop line road A phase or I loop line road B phase or I loop line road C phase.

Protection device calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road

Protection device calculates double-circuit lines on the same pole road I and returns the route protection installation place line fault impedance Z to earth fault_φ:

$Z_{\mathrm{\φ}}=\frac{\{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\}{Z}_{I1}}{\mathrm{Re}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\mathrm{Im}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)}$

Wherein, Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ is I loop line road A phase or I loop line road B phase or I loop line road C phase；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；

Protection device judgesWhether setting up, if setting up, then judging that earth fault is positioned at I loop line road, double-circuit lines on the same pole road protection seting scope, protection device sends action trip signal；Wherein, l_setFor I loop line road, double-circuit lines on the same pole 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, faulted 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; calculate the zero-sequence current on II loop line road, double-circuit lines on the same pole road; then calculate double-circuit lines on the same pole road I and return the line fault impedance to earth fault of the route protection installation place; judge line fault impedance magnitude less than whether impedance magnitude of adjusting is set up; if setting up, then send action trip signal.

The inventive method only uses single-ended single back line electric parameters, it is not necessary to introduce another loop line road electric parameters, and performance, not by the impact of power system operation mode, has very strong adaptive capacity when bigger change occurs power system operation mode.The inventive method takes into account the impact of zero-sequence mutual inductance and earth fault point voltage between line; eliminating the impact on double-circuit lines on the same pole Lu Feitong famous prime minister's cross-line impedance ground distance protection performance of zero-sequence mutual inductance between line, transition resistance and load current, protection domain is reliable and stable.

The foregoing is only the preferred embodiment of the present invention; but protection scope of the present invention is not limited thereto; any those familiar with the art in the technical scope that the invention discloses, the change that can readily occur in or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1. the non-same famous prime minister's cross-line impedance ground distance protecting method of double-circuit line, including 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 currentAnd zero-sequence currentWherein, φ is I loop line road A phase or I loop line road B phase or I loop line road C phase；

(2) protection device calculates the zero-sequence current phase angle α on II loop line road, double-circuit lines on the same pole road:

α=r₁+r₂-π-β

Wherein, $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);$

$b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{10}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});a_3=b_3=\left|\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right|;$

$\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right);$

Z_mFor 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；Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole road；Z_I1Positive sequence impedance for I loop line road, double-circuit lines on the same pole road；φ is I loop line road A phase or I loop line road B phase or I loop line road C phase；

(3) protection device calculates the zero-sequence current on II loop line road, double-circuit lines on the same pole road

(4) protection device calculates double-circuit lines on the same pole road I and returns the route protection installation place line fault impedance Z to earth fault_φ:

$Z_{\mathrm{\φ}}=\frac{\{\mathrm{Re}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Im}\left({\stackrel{\·}{U}}_{\mathrm{I\φ}}\right)\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\}{Z}_{I1}}{\mathrm{Re}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)\mathrm{Im}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})-\mathrm{Re}({\stackrel{\·}{I}}_{I0}+{\stackrel{\·}{I}}_{\mathrm{II}0})\mathrm{Im}\left(Z_{I1}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})\right)}$

Wherein, Z_I0Zero sequence impedance for I loop line road, double-circuit lines on the same pole 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 or I loop line road B phase or I loop line road C phase；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；

(5) protection device judgesWhether setting up, if setting up, then judging that earth fault is positioned at I loop line road, double-circuit lines on the same pole road protection seting scope, protection device sends action trip signal；Wherein, l_setFor I loop line road, double-circuit lines on the same pole road protection seting scope；L is that double-circuit lines on the same pole road I returns line length.