CN104090213A - Double-circuit-line non-same-name phase overline ground fault positioning method - Google Patents

Abstract

The invention discloses a double-circuit-line non-same-name phase overline ground fault positioning method. The method comprises the steps that firstly, fault phase voltages, fault phase voltage break variables, fault phase currents, fault phase current break variables, zero sequence currents and two-normal-phase voltages at the protection mounting position of a same-tower double-circuit line circuit line I are measured, the zero sequence current phase angle of a same-tower double-circuit line circuit line II is calculated, the zero sequence current of the same-tower double-circuit line circuit line II is calculated, the fault phase voltage of the same-tower double-circuit line circuit line I in normal running is calculated, and the characteristic that the voltage break variable amplitude value is monotonically increased from the protection mounting position of double circuit lines to the non-same-name phase overline ground fault point is utilized for precisely positioning a double-circuit-line non-same-name phase overline ground fault. On the basis of the principle, the influence of inter-line zero mutual inductance, transition resistance and load currents on the positioning precision is removed, no distance measurement dead area exists, and when an electric system running mode is changed greatly, the higher positioning precision is still achieved.

Description

The localization method of the non-same famous prime minister's cross-line earth fault of double-circuit line

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 localization method of double-circuit line based on the actual measurement of adjacent lines zero-sequence current.

Background technology

Divide from the electric parameters used of finding range, the method for fault localization can be divided into two large classes: both-end distance measuring and single end distance measurement.Two-terminal Fault Location method is to utilize transmission line of electricity two ends electric parameters to determine the method for transmission line malfunction position, and it need to obtain opposite end electric parameters by passage, therefore strong to the dependence of passage, is also subject to the impact of both-end sampling value synchronization in actual use.Single end distance measurement method is only to utilize the electric current and voltage data of transmission line of electricity one end to determine a kind of method of transmission line malfunction position, because it only needs an end data, need not communication and data synchronizer, operating cost is low and algorithm stable, therefore in mid & low-voltage line, has obtained application widely.At present, method of single end distance measurement is mainly divided into two classes, and a class is traveling wave method, and another kind of is impedance method.Traveling wave method utilizes the transmission character of fault transient travelling wave to find range, and precision is high, not affected by the method for operation, excessive resistance etc., but very high to sampling rate requirement, needs special wave recording device, does not obtain at present substantial application.Impedance method is utilized the voltage after fault, the impedance that the magnitude of current calculates fault loop, the characteristic being directly proportional to impedance according to line length is found range, range measurement principle is simple and reliable, but while being applied to analyses for double circuits on same tower singlephase earth fault one-end fault ranging, distance accuracy is subject to zero-sequence mutual inductance between trouble spot transition resistance and line to be affected serious.Between analyses for double circuits on same tower line, have zero-sequence mutual inductance, zero-sequence mutual inductance can exert an influence to zero sequence compensation coefficient, and then causes impedance method range finding resultant error bigger than normal.If there is single-phase high resistance earthing fault in analyses for double circuits on same tower, be subject to zero-sequence mutual inductance and high transition resistance combined influence between line, impedance method range finding result usually exceeds total track length or without range finding result, abort situation information accurately cannot be provided, cause line fault line walking difficulty, be unfavorable for fault discharge and the fast quick-recovery of line powering fast.

Summary of the invention

The object of the invention is to overcome the deficiency that prior art exists; provide a kind of protection forward to export while there is non-same famous prime minister's cross-line earth fault without range finding dead band; distance accuracy is not subject to the impact of zero-sequence mutual inductance between line, transition resistance and load current, utilizes double-circuit line protection installation place to realize the non-same famous prime minister's cross-line earth fault localization method of double-circuit line to this characteristic of voltage jump amount amplitude monotone increasing of non-same famous prime minister's cross-line earth fault.

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

The localization method of the non-same famous prime minister's cross-line earth fault of double-circuit line, it comprises 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 voltage jump amount fault phase electric current fault phase jump-value of 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 is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA phase;

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

(3) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road ${\stackrel{\·}{I}}_{\mathrm{II}0}={\stackrel{\·}{I}}_{I0}(\cos \mathrm{\α}+j\sin \mathrm{\α});$ Wherein, j is complex operator;

(4) φ phase voltage when protective device calculating analyses for double circuits on same tower I loop line road is normally moved wherein, φ ρ δ is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA phase; J is complex operator;

(5) to choose fault distance initial value be l to protective device _x, with fixed step size Δ, l increases progressively, and calculates successively the constant-voltage bit function of every bit on analyses for double circuits on same tower I loop line road $g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|,$ Until analyses for double circuits on same tower I returns total track length; Wherein, 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; J is complex operator;

(6) protective device is chosen constant-voltage bit function on analyses for double circuits on same tower I loop line road

$g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|$ While reaching minimum value, corresponding point is the non-same famous prime minister's cross-line earth fault of analyses for double circuits on same tower.

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

The inventive method is only used single-ended single back line electric parameters, does not need to introduce another loop line road electric parameters, and positioning precision is not subject to the impact of power system operation mode, still has very high positioning precision in the time that larger change occurs power system operation mode.The inventive method is taken into account the impact of zero-sequence mutual inductance between line, has eliminated the impact of zero-sequence mutual inductance on positioning precision between line.The inventive method utilizes double-circuit line protection installation place to realize the non-same famous prime minister's cross-line earth fault of double-circuit line location to this characteristic of voltage jump amount amplitude monotone increasing of non-same famous prime minister's cross-line earth fault; in principle, eliminated the impact on positioning precision of transition resistance and load current, protection forward exports while there is non-same famous prime minister's cross-line earth fault without range finding dead band.

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 figure, PT is voltage transformer (VT), and 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 voltage jump amount fault phase electric current fault phase jump-value of 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 is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA 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, $r_1={\sin }^{-1}\left(\frac{a_3{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);$ $r_2={\sin }^{-1}\left(\frac{a_1{b}_2-a_2{b}_1}{\sqrt{{\left(a_3{b}_1\right)}^2+{\left(a_1{b}_3\right)}^2}}\right);$ $a_1=\mathrm{Re}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);$ $b_1=\mathrm{Im}\left(\frac{{\stackrel{\·}{U}}_{\mathrm{I\φ}}}{Z_{I1}}\right);$ $a_2=\mathrm{Re}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});$ $b_2=\mathrm{Im}({\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0});$ $a_3=b_3=\left|\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right|;$ $\mathrm{\β}=\mathrm{Arg}\left(\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{I0}\right);$ Z _mfor 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.

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

Fault phase voltage φ phase voltage when protective device calculating analyses for double circuits on same tower I loop line road is normally moved wherein, φ ρ δ is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA phase.

Analyses for double circuits on same tower occurs after non-same famous prime minister's cross-line earth fault, and fault phase voltage when non-same famous prime minister's cross-line earth fault point voltage equals analyses for double circuits on same tower I loop line road and normally moves, equals φ phase voltage and double-circuit line protection installation place is to the voltage jump amount amplitude monotone increasing of non-same famous prime minister's cross-line earth fault, utilizes this voltage magnitude distribution character to propose the non-same famous prime minister's cross-line earth fault fixed-position searching step of double-circuit line as follows:

(1) to choose fault distance initial value be l to protective device _x, with fixed step size Δ, l increases progressively, and calculates successively the constant-voltage bit function of every bit on analyses for double circuits on same tower I loop line road $g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|,$ Until analyses for double circuits on same tower I returns total track length; Wherein, 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; Wherein, j is complex operator.

(2) protective device is chosen constant-voltage bit function on analyses for double circuits on same tower I loop line road

$g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|$ While reaching minimum value, corresponding point is the non-same famous prime minister's cross-line earth fault of analyses for double circuits on same tower.

The inventive method is only used single-ended single back line electric parameters, does not need to introduce another loop line road electric parameters, and positioning precision is not subject to the impact of power system operation mode, still has very high positioning precision in the time that larger change occurs power system operation mode.The inventive method is taken into account the impact of zero-sequence mutual inductance between line, has eliminated the impact of zero-sequence mutual inductance on positioning precision between line.The inventive method utilizes double-circuit line protection installation place to realize the non-same famous prime minister's cross-line earth fault of double-circuit line location to this characteristic of voltage jump amount amplitude monotone increasing of non-same famous prime minister's cross-line earth fault; in principle, eliminated the impact on positioning precision of transition resistance and load current, protection forward exports while there is non-same famous prime minister's cross-line earth fault without range finding dead band.

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. the localization method of the non-same famous prime minister's cross-line earth fault of double-circuit line, 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 voltage jump amount fault phase electric current fault phase jump-value of 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 is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA phase;

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

(3) protective device calculates the zero-sequence current on analyses for double circuits on same tower II loop line road ${\stackrel{\·}{I}}_{\mathrm{II}0}={\stackrel{\·}{I}}_{I0}(\cos \mathrm{\α}+j\sin \mathrm{\α});$ Wherein, j is complex operator;

(4) φ phase voltage when protective device calculating analyses for double circuits on same tower I loop line road is normally moved wherein, φ ρ δ is I loop line road ACB phase or I loop line road BAC phase or I loop line road CBA phase; J is complex operator;

(5) to choose fault distance initial value be l to protective device _x, with fixed step size Δ, l increases progressively, and calculates successively the constant-voltage bit function of every bit on analyses for double circuits on same tower I loop line road $g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|,$ Until analyses for double circuits on same tower I returns total track length; Wherein, 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; J is complex operator;

(6) protective device is chosen constant-voltage bit function on analyses for double circuits on same tower I loop line road $g\left(l_x\right)=\left|\right|{\mathrm{\Δ}\stackrel{\·}{U}}_{\mathrm{I\φ}}-Z_{I1}\frac{l_x}{l}(\mathrm{\Δ}{\stackrel{\·}{I}}_{\mathrm{I\φ}}+\frac{Z_{I0}-Z_{I1}}{Z_{I1}}{\stackrel{\·}{I}}_{I0}+\frac{Z_m}{{3Z}_{I1}}{\stackrel{\·}{I}}_{\mathrm{II}0})|-|-j\frac{{\stackrel{\·}{U}}_{\mathrm{I\ρ}}-{\stackrel{\·}{U}}_{\mathrm{I\δ}}}{\sqrt{3}}\left|\right|$ While reaching minimum value, corresponding point is the non-same famous prime minister's cross-line earth fault of analyses for double circuits on same tower.