CN104953566A - Voltage protection method for non-homonymic phase overline grounding fault of double-circuit line with full transient action characteristic - Google Patents

Abstract

The invention discloses a voltage protection method for a non-homonymic phase overline grounding fault of a double-circuit line with a full transient action characteristic. The method only needs the electrical amount of a single-end single-circuit line, and the electrical quantity of another circuit line is not needed to be introduced, so that the action performance is not affected by the operating mode of a power system; when the operating mode of the power system is changed to a greater extent, the power system is extremely high in applicability. According to the method, the influence caused by the interline zero-sequence mutual inductance is metered, so that the influence of the interline zero-sequence mutual inductance on the protection action performance is eliminated. In the method, the voltage of the line before fault is not needed to be memorized, and retaining loop for the voltage of the line before fault is not needed to be set, so that the hardware design of a relay protection device is simplified. The operating characteristic circle of the method passes through a third quadrant, and the origin of coordinates is positioned in the operating characteristic circle, so that no protection dead zone exists in the non-homonymic phase overline grounding fault of a positive outlet, and no mis-operation is caused in the non-homonymic phase overline grounding fault of a negative outlet.

Description

There is the non-same famous prime minister's cross-line earth fault voltage protection method of double-circuit line of full transient state operating characteristics

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to a kind of non-same famous prime minister's cross-line earth fault voltage protection method of double-circuit line with full transient state operating characteristics.

Background technology

Analyses for double circuits on same tower has that floor space is few, cost is low, connects operation of power networks reliable and stable, has become a kind of common transmission line connected mode of electric power system.Zero-sequence mutual inductance is there is between analyses for double circuits on same tower line; zero-sequence mutual inductance has an impact to zero-utility theory; and then generation additional impedance; the additional impedance caused because of zero-sequence mutual inductance can cause protector measuring to fault impedance be greater than physical fault impedance; when causing close protection seting scope place generation earth fault in analyses for double circuits on same tower protection zone; there is misoperation in protection, unfavorable to power network safety operation.

Even if analyses for double circuits on same tower occur through the direct earth fault of shaft tower, soil resistivity lower ground district's transition resistance also near 10 Ω; The local transition resistance higher in resistivity can reach 30 Ω, or even higher.The non-vanishing fault impedance that protective device is calculated of transition resistance, except 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 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, even likely can threaten the stability of electric power system.

Operating characteristics round edge circle of existing analyses for double circuits on same tower ground distance protection is through the origin of coordinates; because the origin of coordinates is positioned on operating characteristics round edge circle; during protection forward outlet earth fault there is dead band in protection; and along with transition resistance and load current increase, protection forward outlet dead band is larger.Because the origin of coordinates is positioned on operating characteristics round edge circle, there is the possibility of malfunction in protection in the other direction outlet earth fault, and transition resistance is larger, protection easier misoperation during protection opposite direction outlet earth fault.

Owing to there is very strong zero-sequence mutual inductance between analyses for double circuits on same tower line; existing single-phase earthing distance protection cannot obtain the zero-sequence current on another loop line road; the impact of zero-sequence mutual inductance between line cannot be eliminated in algorithm model; by the impact of zero-sequence mutual inductance between line; when traditional single phase ground distance protection is applied to analyses for double circuits on same tower, its protection range will expand greatly; at protection seting scope place usually there is steady-state in fault; make easily misoperation to occur during protection external area error; easily cause the large transfer of trend, cause large area blackout and occur.

Summary of the invention

The object of the invention is to the deficiency overcoming prior art existence, a kind of origin of coordinates is provided to be positioned at operating characteristics circle, unprotect dead band during protection forward outlet non-same famous prime minister's cross-line earth fault, protect not misoperation when exporting non-same famous prime minister's cross-line earth fault in the other direction, without the need to remembering voltage before line fault, loop is kept without the need to arranging voltage before line fault, simplify protective relaying device hardware designs, operating characteristics is all transient state operating characteristics in the whole failure process of the non-same famous prime minister's cross-line earth fault of double-circuit line, performance is not by zero-sequence mutual inductance between line, the non-same famous prime minister's cross-line earth fault voltage protection method of double-circuit line of transition resistance and load current impact.

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

There is the non-same famous prime minister's cross-line earth fault voltage protection method of double-circuit line of full transient state operating characteristics, it is characterized in that, comprise following sequential steps:

(1) protector measuring analyses for double circuits on same tower I returns the faulted phase voltage of route protection installation place faulted phase current and zero-sequence current measure the two normal phase voltages that analyses for double circuits on same tower I goes back to route protection installation place wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; Namely I loop line road φ phase breaks down, and ρ δ is two normal phases; φ ρ δ forms I loop line road ABC three-phase;

(2) protective device calculates the zero-sequence current phase angle α=r on analyses for double circuits on same tower II loop line road ₁+ r ₂-π-β;

Wherein, 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; 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 ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; $a_3=b_3=\left|\frac{Z_m}{3Z_{11}}{\stackrel{\·}{I}}_{I0}\right|,$ For amplitude; $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{11}}{\stackrel{\·}{I}}_{I0}\right),$ For phase angle; $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),$ For ${\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}$ Real part; $b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{.}{I}}_{I0}),$ For ${\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}$ Imaginary part; $a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For real part; $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For imaginary part; r ₁, r ₂for intermediate variable, without physical significance, and $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);{\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right)$ For arcsin function value; ${\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right)$ For arcsin function value;

(3) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road wherein, j is complex operator;

(4) protective device calculates φ phase voltage when analyses for double circuits on same tower I loop line road is normally run wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase;

(5) protective device judges ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop in (-90 °, 90 °) scope and whether set up, if set up, then judge that non-same famous prime minister's cross-line earth fault is positioned at analyses for double circuits on same tower I loop line road protection seting scope, protective device sends action trip signal; Otherwise, if judge ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop in (90 °, 270 °) scope, then protective device sends block signal; Wherein, l _setfor analyses for double circuits on same tower I loop line road protection seting scope, get 0.85 times of analyses for double circuits on same tower I and return line length; 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; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; 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; φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase.

Feature of the present invention and technological achievement:

The inventive method only uses single-ended single back line electric parameters, does not need 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 larger change occurs power system operation mode.The inventive method takes into account the impact of zero-sequence mutual inductance between line, to eliminate between line zero-sequence mutual inductance to the impact of Perfomance of protective relaying.The inventive method, without the need to remembering voltage before line fault, keeping loop without the need to arranging voltage before line fault, simplifying protective relaying device hardware designs.The operating characteristics circle of the inventive method is through third quadrant, and the origin of coordinates is positioned at operating characteristics circle, and unprotect dead band during protection forward outlet non-same famous prime minister's cross-line earth fault, protects not misoperation when exporting non-same famous prime minister's cross-line earth fault in the other direction.The inventive method operating characteristics is all transient state operating characteristics in the whole failure process of the non-same famous prime minister's cross-line earth fault of double-circuit line; there is the ability of very strong anti-transition resistance and load current impact, be applicable to the relaying protection of the whole failure process of the non-same famous prime minister's cross-line earth fault of double-circuit line.

Accompanying drawing explanation

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, and m, n are the two ends numbering of analyses for double circuits on same tower.Protector measuring analyses for double circuits on same tower I returns the faulted phase voltage of route protection installation place faulted phase current and zero-sequence current measure the two normal phase voltages that analyses for double circuits on same tower I goes back to route protection installation place wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; Namely I loop line road φ phase breaks down, and ρ δ is two normal phases; φ ρ δ forms I loop line road ABC three-phase, even φ=A phase, ρ δ=CB phase; If φ=B phase, ρ δ=AC phase; If φ=C phase, ρ δ=BA phase.

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

α＝r ₁+r ₂-π-β

Wherein, 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; 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 ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; $a_3=b_3=\left|\frac{Z_m}{3Z_{11}}{\stackrel{\·}{I}}_{I0}\right|,$ For amplitude; $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{11}}{\stackrel{\·}{I}}_{I0}\right),$ For phase angle; $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),$ For ${\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}$ Real part; $b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{.}{I}}_{I0}),$ For ${\stackrel{.}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}$ Imaginary part; $a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For real part; $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For imaginary part; r ₁, r ₂for intermediate variable, without physical significance, and $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);{\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right)$ For arcsin function value; ${\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right)$ For arcsin function value.

Protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road wherein, j is complex operator.

Protective device calculates φ phase voltage when analyses for double circuits on same tower I loop line road is normally run wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase.

If the non-same famous prime minister's cross-line earth fault of double-circuit line is positioned within protection seting scope, then ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop within (-90 °, 90 °) scope; If the non-same famous prime minister's cross-line earth fault of double-circuit line is positioned at outside protection seting scope, then ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop in (90 °, 270 °) scope, according to this voltage-phase characteristic, the non-same famous prime minister's cross-line earth fault voltage protection criterion of a kind of double-circuit line is proposed as follows:

Protective device judges ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop in (-90 °, 90 °) scope and whether set up, if set up, then judge that non-same famous prime minister's cross-line earth fault is positioned at analyses for double circuits on same tower I loop line road protection seting scope, protective device sends action trip signal; Otherwise, if judge ${\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_{\mathrm{set}}}{l}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})$ Leading angle drop in (90 °, 270 °) scope, then protective device sends block signal; Wherein, l _setfor analyses for double circuits on same tower I loop line road protection seting scope, get 0.85 times of analyses for double circuits on same tower I and return line length; 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; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; 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; φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase.

The inventive method only uses single-ended single back line electric parameters, does not need 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 larger change occurs power system operation mode.The inventive method takes into account the impact of zero-sequence mutual inductance between line, to eliminate between line zero-sequence mutual inductance to the impact of Perfomance of protective relaying.The inventive method, without the need to remembering voltage before line fault, keeping loop without the need to arranging voltage before line fault, simplifying protective relaying device hardware designs.

The operating characteristics circle of the inventive method is through third quadrant, and the origin of coordinates is positioned at operating characteristics circle, and unprotect dead band during protection forward outlet non-same famous prime minister's cross-line earth fault, protects not misoperation when exporting non-same famous prime minister's cross-line earth fault in the other direction.The operating characteristics of the inventive method is all transient state operating characteristics in the whole failure process of the non-same famous prime minister's cross-line earth fault of double-circuit line, has the ability of very strong anti-transition resistance and load current impact.

The foregoing is only 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 change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.

Claims (1)

1. there is the non-same famous prime minister's cross-line earth fault voltage protection method of double-circuit line of full transient state operating characteristics, it is characterized in that, comprise following sequential steps:

(1) protector measuring analyses for double circuits on same tower I returns the faulted phase voltage of route protection installation place faulted phase current and zero-sequence current measure the two normal phase voltages that analyses for double circuits on same tower I goes back to route protection installation place wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; Namely I loop line road φ phase breaks down, and ρ δ is two normal phases; φ ρ δ forms I loop line road ABC three-phase.

(2) protective device calculates the zero-sequence current phase angle α=r on analyses for double circuits on same tower II loop line road ₁+ r ₂-π-β;

Wherein, 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; 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 ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase; $a_3=b_3=\left|\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right|,$ For amplitude; $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{3Z_{I1}}{\stackrel{\·}{I}}_{I0}\right),$ For phase angle; $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),$ For real part; $b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}),$ For imaginary part; $a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For real part; $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right),$ For imaginary part; r ₁, r ₂for intermediate variable, without physical significance, and $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right),r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);$ for arcsin function value; for arcsin function value.

(3) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road wherein, j is complex operator.

(4) protective device calculates φ phase voltage when analyses for double circuits on same tower I loop line road is normally run wherein, φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase.

(5) protective device judges leading angle drop in (-90 °, 90 °) scope and whether set up, if set up, then judge that non-same famous prime minister's cross-line earth fault is positioned at analyses for double circuits on same tower I loop line road protection seting scope, protective device sends action trip signal; Otherwise, if judge leading angle drop in (90 °, 270 °) scope, then protective device sends block signal; Wherein, l _setfor analyses for double circuits on same tower I loop line road protection seting scope, get 0.85 times of analyses for double circuits on same tower I and return line length; 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; Z _i1for the positive sequence impedance on analyses for double circuits on same tower I loop line road; 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; φ ρ δ=I loop line road ACB phase, I loop line road BAC phase, I loop line road CBA phase.