CN104052035A - Same-tower double-circuit line single-phase grounded reactance relay - Google Patents

Abstract

The invention discloses a same-tower double-circuit line single-phase grounded reactance relay. According to the method, the fault phase electric quantity of the protection mounting position of a circuit line of a same-tower double-circuit line I is firstly measured, the zero sequence current of a circuit line of a same-tower double-circuit line II is calculated, then, the influence of the zero sequence current of the circuit line of the same-tower double-circuit line II is calculated, the motion voltage within the protection setting range of the circuit line of the same-tower double-circuit line I is calculated, whether the phase angle of the motion voltage, ahead of the fault phase negative sequence current, within the protection setting range of the circuit line of the same-tower double-circuit line I is from 180 degrees to 360 degrees or not is judged, and if the phase angle is from 180 degrees to 360 degrees, a protecting device sends out a motion trip signal, and trips off breakers at the two ends of the circuit line of the same-tower double-circuit line I. According to the method, the influence of the zero mutual inductance between the lines on the protection motion performance of the same-tower double-circuit line single-phase grounded relay is removed, and the influence of the transition resistance and the load currents on the protection motion performance is avoided.

Description

Analyses for double circuits on same tower single-phase earthing reactance relay

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to a kind of analyses for double circuits on same tower single-phase earthing reactance relay based on single back line single-end electrical quantity.

Background technology

Between analyses for double circuits on same tower line, there is zero-sequence mutual inductance; zero-sequence mutual inductance exerts an influence to zero sequence compensation coefficient; and then generation additional impedance; the additional impedance causing because of zero-sequence mutual inductance can cause protector measuring to fault impedance be greater than physical fault impedance; cause in analyses for double circuits on same tower protection zone while there is single phase ground fault near protection setting range place; there is misoperation in protection, unfavorable to power network safety operation.

Even if analyses for double circuits on same tower occurs through the direct earth fault of shaft tower, at the lower regional transition resistance of soil resistivity also near 10 Ω; The local transition resistance higher in resistivity can reach 30 Ω, or even higher.Transition resistance is non-vanishing makes fault impedance that protective device calculates except the fault impedance component that comprises reaction true fault distance, has also comprised the additional impedance producing because of transition resistance.The additional impedance that transition resistance produces is resistance sense or is capacitance-resistance and easily causes impedance ground distance protection tripping or steady-state.Protection malfunction or tripping, can bring great loss to safe operation of power system, even likely can threaten the stability of electric power system.

Single phase ground fault accounts for the more than 80% of analyses for double circuits on same tower fault type; the protection problem of single-phase high resistance earthing fault is never solved preferably, studies a kind of performance and is not subject to the analyses for double circuits on same tower single phase ground fault relay protecting method that between line, zero-sequence mutual inductance and transition resistance affect to have very important engineering using value.

Summary of the invention

The object of the invention is to overcome the deficiency that prior art exists, provide a kind of performance not to be subject to the analyses for double circuits on same tower single-phase earthing reactance relay based on single back line single-end electrical quantity that between transition resistance, load current and line, zero-sequence mutual inductance affects.

The technical scheme adopting that the present invention solves its technical problem is:

1. analyses for double circuits on same tower single-phase earthing reactance relay, is characterized in that: comprise following sequential steps:

(1) protector measuring analyses for double circuits on same tower I returns the fault phase voltage of route protection installation place fault phase electric current fault phase negative-sequence current and zero-sequence current wherein, φ is I loop line road A phase, I loop line road B phase, I loop line road C phase;

(2) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road

${\stackrel{.}{I}}_{\mathrm{II}0}=\frac{(l_{\mathrm{set}}{Z}_{n0}-(l-l_{\mathrm{set}})Z_{m0}){\stackrel{.}{I}}_{I0}}{(2l-l_{\mathrm{set}})Z_{n0}+(l-l_{\mathrm{set}})(Z_{m0}+Z_{I0}+Z_m)}$

Wherein, Z _m0for the zero sequence system equivalent impedance of this side of analyses for double circuits on same tower I loop line road protection installation place; Z _n0for the zero sequence system equivalent impedance of analyses for double circuits on same tower I loop line road offside protection installation place; Z _mfor the zero-sequence mutual inductance between analyses for double circuits on same tower I loop line road and analyses for double circuits on same tower II loop line road; L is that analyses for double circuits on same tower I returns line length; Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; l _setfor analyses for double circuits on same tower I returns route protection setting range;

(3) protective device calculates analyses for double circuits on same tower I and returns route protection setting range l _setthe operation voltage at place

${\stackrel{.}{U}}_{\mathrm{op}}\left(l_{\mathrm{set}}\right)={\stackrel{.}{U}}_{\mathrm{I\φ}}-\frac{Z_{I1}{l}_{\mathrm{set}}}{l}({\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{.}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{.}{I}}_{\mathrm{II}0})$

Wherein, Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; φ is I loop line road A phase, I loop line road B phase, I loop line road C phase; for fault phase voltage; for fault phase electric current; for zero-sequence current; Z _mfor the zero-sequence mutual inductance between analyses for double circuits on same tower I loop line road and analyses for double circuits on same tower II loop line road; L is that analyses for double circuits on same tower I returns line length;

(4) protective device judges that analyses for double circuits on same tower I returns route protection setting range l _setthe operation voltage at place leading fault phase negative-sequence current phase angle drop in [180 °, 360 °] scope and whether set up, if set up, protective device sends action trip signal, two ends, tripping analyses for double circuits on same tower I loop line road circuit breaker.

The technical program is compared with background technology, and its tool has the following advantages:

The fault phase electric parameters that the inventive method utilizes analyses for double circuits on same tower I to go back to route protection installation place is calculated the zero-sequence current on analyses for double circuits on same tower II loop line road, take into account the impact of analyses for double circuits on same tower II loop line road zero-sequence current, calculate the operation voltage that analyses for double circuits on same tower I goes back to route protection setting range place, judge that the phase angle that analyses for double circuits on same tower I returns the leading fault phase negative-sequence current of operation voltage at route protection setting range place drops on [180 °, 360 °] whether set up in scope, if set up, protective device sends action trip signal, two ends, tripping analyses for double circuits on same tower I loop line road circuit breaker.In the inventive method algorithm model, consider the impact of zero-sequence mutual inductance between line, eliminated the impact of zero-sequence mutual inductance on analyses for double circuits on same tower single phase ground fault relaying protection performance between line.The angle relationship that the inventive method is returned according to analyses for double circuits on same tower I between operation voltage and the fault phase negative-sequence current at route protection setting range place forms protection criterion, has overcome the impact on Perfomance of protective relaying of transition resistance and load current.

Brief description of the drawings

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

Fig. 1 is application analyses for double circuits on same tower transmission system schematic diagram of the present invention.

Embodiment

Fig. 1 is application analyses for double circuits on same tower transmission system schematic diagram of the present invention.In Fig. 1, PT is voltage transformer; CT is current transformer.Protector measuring analyses for double circuits on same tower I returns the fault phase voltage of route protection installation place fault phase electric current fault phase negative-sequence current and zero-sequence current wherein, φ is I loop line road A phase, I loop line road B phase, I loop line road C phase.

Protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road

${\stackrel{.}{I}}_{\mathrm{II}0}=\frac{(l_{\mathrm{set}}{Z}_{n0}-(l-l_{\mathrm{set}})Z_{m0}){\stackrel{.}{I}}_{I0}}{(2l-l_{\mathrm{set}})Z_{n0}+(l-l_{\mathrm{set}})(Z_{m0}+Z_{I0}+Z_m)}$

Wherein, Z _m0for the zero sequence system equivalent impedance of this side of analyses for double circuits on same tower I loop line road protection installation place; Z _n0for the zero sequence system equivalent impedance of analyses for double circuits on same tower I loop line road offside protection installation place; Z _mfor the zero-sequence mutual inductance between analyses for double circuits on same tower I loop line road and analyses for double circuits on same tower II loop line road; L is that analyses for double circuits on same tower I returns line length; Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; l _setfor analyses for double circuits on same tower I returns route protection setting range.

Protective device calculates analyses for double circuits on same tower I and returns route protection setting range l _setthe operation voltage at place

${\stackrel{.}{U}}_{\mathrm{op}}\left(l_{\mathrm{set}}\right)={\stackrel{.}{U}}_{\mathrm{I\φ}}-\frac{Z_{I1}{l}_{\mathrm{set}}}{l}({\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{.}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{.}{I}}_{\mathrm{II}0})$

Wherein, Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; φ=I loop line road A phase, I loop line road B phase, I loop line road C phase; for fault phase voltage; for fault phase electric current; for fault phase negative-sequence current; for zero-sequence current.

Protective device calculates analyses for double circuits on same tower I and returns route protection setting range l _setthe operation voltage at place leading fault phase negative-sequence current phase angle judgement whether drop in (180 °, 360 °) scope and set up, if set up, protective device sends action trip signal, two ends, tripping analyses for double circuits on same tower I loop line road circuit breaker.

The fault phase electric parameters that the inventive method utilizes analyses for double circuits on same tower I to go back to route protection installation place is calculated the zero-sequence current on analyses for double circuits on same tower II loop line road, take into account the impact of analyses for double circuits on same tower II loop line road zero-sequence current, calculate the operation voltage that analyses for double circuits on same tower I goes back to route protection setting range place, judge that the phase angle that analyses for double circuits on same tower I returns the leading fault phase negative-sequence current of operation voltage at route protection setting range place drops on [180 °, 360 °] whether set up in scope, if set up, protective device sends action trip signal, two ends, tripping analyses for double circuits on same tower I loop line road circuit breaker.In the inventive method algorithm model, consider the impact of zero-sequence mutual inductance between line, eliminated the impact of zero-sequence mutual inductance on analyses for double circuits on same tower single phase ground fault relaying protection performance between line.The angle relationship that the inventive method is returned according to analyses for double circuits on same tower I between operation voltage and the fault phase negative-sequence current at route protection setting range place forms protection criterion, has overcome the impact on Perfomance of protective relaying of transition resistance and load current.

The above, only for preferred embodiment of the present invention, therefore can not limit according to this scope of the invention process, the equivalence of doing 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. analyses for double circuits on same tower single-phase earthing reactance relay, is characterized in that: comprise following sequential steps:

(1) protector measuring analyses for double circuits on same tower I returns the fault phase voltage of route protection installation place fault phase electric current fault phase negative-sequence current and zero-sequence current wherein, φ is I loop line road A phase, I loop line road B phase, I loop line road C phase;

(2) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road

${\stackrel{.}{I}}_{\mathrm{II}0}=\frac{(l_{\mathrm{set}}{Z}_{n0}-(l-l_{\mathrm{set}})Z_{m0}){\stackrel{.}{I}}_{I0}}{(2l-l_{\mathrm{set}})Z_{n0}+(l-l_{\mathrm{set}})(Z_{m0}+Z_{I0}+Z_m)}$

Wherein, Z _m0for the zero sequence system equivalent impedance of this side of analyses for double circuits on same tower I loop line road protection installation place; Z _n0for the zero sequence system equivalent impedance of analyses for double circuits on same tower I loop line road offside protection installation place; Z _mfor the zero-sequence mutual inductance between analyses for double circuits on same tower I loop line road and analyses for double circuits on same tower II loop line road; L is that analyses for double circuits on same tower I returns line length; Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; l _setfor analyses for double circuits on same tower I returns route protection setting range;

(3) protective device calculates analyses for double circuits on same tower I and returns route protection setting range l _setthe operation voltage at place

${\stackrel{.}{U}}_{\mathrm{op}}\left(l_{\mathrm{set}}\right)={\stackrel{.}{U}}_{\mathrm{I\φ}}-\frac{Z_{I1}{l}_{\mathrm{set}}}{l}({\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{.}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{.}{I}}_{\mathrm{II}0})$

Wherein, Z _i0for the zero sequence impedance on analyses for double circuits on same tower I loop line road; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; φ is I loop line road A phase, I loop line road B phase, I loop line road C phase; for fault phase voltage; for fault phase electric current; for zero-sequence current; Z _mfor the zero-sequence mutual inductance between analyses for double circuits on same tower I loop line road and analyses for double circuits on same tower II loop line road; L is that analyses for double circuits on same tower I returns line length;

(4) protective device judges that analyses for double circuits on same tower I returns route protection setting range l _setthe operation voltage at place leading fault phase negative-sequence current phase angle drop in [180 °, 360 °] scope and whether set up, if set up, protective device sends action trip signal, two ends, tripping analyses for double circuits on same tower I loop line road circuit breaker.