CN105203903A - Electric transmission line phase-to-phase fault direction recognizing method based on dynamic data window - Google Patents

Abstract

The invention discloses an electric transmission line phase-to-phase fault direction recognizing method based on a dynamic data window. The method comprises the steps that a fault phase-to-phase voltage sampling value, a fault phase-to-phase current sampling value and a fault phase-to-phase negative sequence voltage sampling value at each sampling time at an electric transmission line protective installation position are measured, the length of the dynamic data window is calculated, a fault phase-to-phase electric quantity sampling valve of the length of the dynamic data window is utilized for calculating whether electric line phase-to-phase short-circuit fault direction criterion is set up or not; if yes, it is judged that the electric transmission line positive direction has a phase-to-phase short-circuit fault. Only fault phase-to-phase electric quantity sampling values of the data window within a 1/4 period are used for operation, the algorithm principle is simple, the program is easy to achieve, the number of needed data windows is small, the calculation quantity is small, and the operation speed is high. According to the method, a recognition result is not affected by an electric system running way or a fault position or the transmission resistance or the load current or the other factors, and the electric transmission line phase-to-phase fault direction can be judged accurately.

Description

Based on dynamic data window electric transmission line phase fault discriminating direction method

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to a kind of based on dynamic data window electric transmission line phase fault discriminating direction method.

Background technology

In actual electric network, trouble spot may be positioned at transmission line of electricity in the other direction, also may be positioned at transmission line of electricity positive dirction.If trouble spot is positioned at transmission line of electricity in the other direction, then protected circuit protective relaying device is failure to actuate, but by the protective relaying device action of adjacent lines by fault isolation.If trouble spot is positioned at transmission line of electricity positive dirction, then by the protective relaying device action of protected circuit, the fault on protected circuit is isolated.Existing transmission line of electricity discriminating direction element mainly contains zero sequence power direction element, negative-sequence power direction element and zero-sequence direction component, negative-sequence direction component, zero sequence power direction element, negative-sequence power direction element and zero-sequence direction component, electric parameters used by negative-sequence direction component algorithm are all phasor, the data window of a whole ripple is needed to participate in computing, relate to comparatively complicated Fourier algorithm computing, therefore conventional transmission lines road discriminating direction element real-time is not strong.If when fault is positioned at protected circuit opposite direction near-end; phase current power frequency variation, negative-sequence current and zero-sequence current protection criterion can rapid actions; now conventional transmission lines road discriminating direction element cannot in time by protective relaying device locking; cause the misoperation of protected circuit protective relaying device; fault coverage is caused to expand; the stabilization of power grids is impacted, is unfavorable for power network safety operation.

Summary of the invention

The object of the invention is to the deficiency overcoming prior art existence, provide a kind of based on dynamic data window electric transmission line phase fault discriminating direction method.Voltage sample value between the fault phase that the inventive method measures each sampling instant of line protection installation place, negative sequence voltage sampled value between current sampling data and fault phase between fault phase; calculate dynamic data window length; electrical quantity sampling value computing electric power line phase fault direction criterion between the fault phase of a dynamic data window length is utilized whether to set up; if set up, then judge transmission line of electricity positive dirction generation phase fault.The inventive method only need use be less than 1/4 cycle data window fault phase between electrical quantity sampling value participate in computing, algorithm principle is simple, and program realizes easily, and desired data window is few, and calculated amount is little, fast operation.The inventive method differentiates result not by the impact of the factors such as power system operation mode, abort situation, transition resistance and load current, accurately can differentiate the fault direction of electric transmission line phase fault.

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

Based on dynamic data window electric transmission line phase fault discriminating direction method, it is characterized in that, comprise following sequential steps:

(1) negative sequence voltage sampled value between current sampling data and fault phase between voltage sample value, fault phase between the fault phase of each sampling instant of protective device Real-time Collection line protection installation place;

(2) protective device calculates dynamic data window length wherein, z ₁for unit length electric transmission line positive sequence impedance; Arg (z ₁) be unit length electric transmission line positive sequence impedance z ₁phase angle; N is every cycle sampling number;

(3) protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{\left|z_1\right|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{\left|z_1\right|}<0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-2\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t\right)}{\left|z_1\right|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t\right)}{\left|z_1\right|}<0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault;

(4) protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{\left|z_1\right|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{\left|z_1\right|}>0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-2\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t\right)}{\left|z_1\right|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t\right)}{\left|z_1\right|}>0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault;

Wherein, u _{φ φ}(t), u _{φ φ}voltage sample value between the fault phase that (t-Δ t) is respectively t, t-Δ t sampling instant; u _{φ φ 2}(t-L Δ t), u _{φ φ 2}negative sequence voltage sampled value between the fault phase that (t-L Δ t-Δ t) is respectively t-L Δ t, t-L Δ t-Δ t sampling instant; i _{φ φ}(t), i _{φ φ}(t-Δ t), i _{φ φ}current sampling data between the fault phase that (t-2 Δ t) is respectively t, t-Δ t, t-2 Δ t sampling instant; Δ t is sampling interval duration; l ₁, r ₁be respectively unit length electric transmission line positive sequence inductance, positive sequence resistance; φ φ=AB, BC, CA are alternate; | z ₁| be unit length electric transmission line positive sequence impedance z ₁amplitude.

The present invention compared with prior art, has following positive achievement:

Voltage sample value between the fault phase that the inventive method measures each sampling instant of line protection installation place, negative sequence voltage sampled value between current sampling data and fault phase between fault phase; calculate dynamic data window length; electrical quantity sampling value computing electric power line phase fault direction criterion between the fault phase of a dynamic data window length is utilized whether to set up; if set up, then judge transmission line of electricity positive dirction generation phase fault.The inventive method only need use be less than 1/4 cycle data window fault phase between electrical quantity sampling value participate in computing, algorithm principle is simple, and program realizes easily, and desired data window is few, and calculated amount is little, fast operation.The inventive method differentiates result not by the impact of the factors such as power system operation mode, abort situation, transition resistance and load current, accurately can differentiate the fault direction of electric transmission line phase fault.

Accompanying drawing explanation

Fig. 1 is application multi-line power transmission system schematic of the present invention.

Embodiment

According to Figure of description, technical scheme of the present invention is expressed in further detail below.

Fig. 1 is application multi-line power transmission system schematic of the present invention.In Fig. 1, CVT is voltage transformer (VT), CT is current transformer.Negative sequence voltage sampled value between current sampling data and fault phase between voltage sample value, fault phase between the fault phase of each sampling instant of protective device Real-time Collection line protection installation place.

Protective device unit of account length electric transmission line positive sequence impedance z ₁phase angle Arg (z ₁).

Protective device unit of account length electric transmission line positive sequence impedance z ₁amplitude | z ₁|.

Protective device calculates dynamic data window length wherein, N is every cycle sampling number.

Protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{\left|z_1\right|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{\left|z_1\right|}<0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-2\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t\right)}{\left|z_1\right|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t\right)}{\left|z_1\right|}<0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault.

Protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{\left|z_1\right|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{\left|z_1\right|}>0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-2\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t\right)}{\left|z_1\right|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t-\mathrm{\&Delta;}t\right)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}\left(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t\right)}{\left|z_1\right|}>0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault.

Wherein, u _{φ φ}(t), u _{φ φ}voltage sample value between the fault phase that (t-Δ t) is respectively t, t-Δ t sampling instant; u _{φ φ 2}(t-L Δ t), u _{φ φ 2}negative sequence voltage sampled value between the fault phase that (t-L Δ t-Δ t) is respectively t-L Δ t, t-L Δ t-Δ t sampling instant; i _{φ φ}(t), i _{φ φ}(t-Δ t), i _{φ φ}current sampling data between the fault phase that (t-2 Δ t) is respectively t, t-Δ t, t-2 Δ t sampling instant; Δ t is sampling interval duration; l ₁, r ₁be respectively unit length electric transmission line positive sequence inductance, positive sequence resistance; φ φ=AB, BC, CA are alternate.

Voltage sample value between the fault phase that the inventive method measures each sampling instant of line protection installation place, negative sequence voltage sampled value between current sampling data and fault phase between fault phase; calculate dynamic data window length; electrical quantity sampling value computing electric power line phase fault direction criterion between the fault phase of a dynamic data window length is utilized whether to set up; if set up, then judge transmission line of electricity positive dirction generation phase fault.The inventive method only need use be less than 1/4 cycle short-data windows fault phase between electrical quantity sampling value participate in computing, algorithm principle is simple, and realize easily, desired data window is few, and calculated amount is little, fast operation.The inventive method differentiates result not by the impact of the factors such as power system operation mode, abort situation, transition resistance and load current, accurately can differentiate the fault direction of electric transmission line phase fault.

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., based on dynamic data window electric transmission line phase fault discriminating direction method, comprise following sequential steps:

(1) negative sequence voltage sampled value between current sampling data and fault phase between voltage sample value, fault phase between the fault phase of each sampling instant of protective device Real-time Collection line protection installation place;

(2) protective device calculates dynamic data window length wherein, z ₁for unit length electric transmission line positive sequence impedance; Arg (z ₁) be unit length electric transmission line positive sequence impedance z ₁phase angle; N is every cycle sampling number;

(3) protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{|z_1|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{|z_1|}<0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-2\mathrm{\&Delta;}t)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{|z_1|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{|z_1|}<0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault;

(4) protective device judges $u_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{|z_1|}-u_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{|z_1|}>0$ Whether set up, if set up, then judge $\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-2\mathrm{\&Delta;}t)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t)}{|z_1|}-\&lsqb;l_1\frac{i_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)-i_{\mathrm{\&phi;}\mathrm{\&phi;}}(t-\mathrm{\&Delta;}t)}{\mathrm{\&Delta;}t}+r_1{i}_{\mathrm{\&phi;}\mathrm{\&phi;}}\left(t\right)\&rsqb;\frac{u_{\mathrm{\&phi;}\mathrm{\&phi;}2}(t-L\mathrm{\&Delta;}t-\mathrm{\&Delta;}t)}{|z_1|}>0$ Whether set up, if set up, then protective device judges transmission line of electricity positive dirction generation phase fault;

Wherein, u _{φ φ}(t), u _{φ φ}voltage sample value between the fault phase that (t-Δ t) is respectively t, t-Δ t sampling instant; u _{φ φ 2}(t-L Δ t), u _{φ φ 2}negative sequence voltage sampled value between the fault phase that (t-L Δ t-Δ t) is respectively t-L Δ t, t-L Δ t-Δ t sampling instant; i _{φ φ}(t), i _{φ φ}(t-Δ t), i _{φ φ}current sampling data between the fault phase that (t-2 Δ t) is respectively t, t-Δ t, t-2 Δ t sampling instant; Δ t is sampling interval duration; l ₁, r ₁be respectively unit length electric transmission line positive sequence inductance, positive sequence resistance; φ φ=AB, BC, CA are alternate; | z ₁| be unit length electric transmission line positive sequence impedance z ₁amplitude.