CN103777118B - Negative sequence component is utilized to realize the system of selection of T link fault branch - Google Patents

Abstract

The invention discloses one utilizes negative sequence component to realize the system of selection of T link fault branch.The inventive method measures fault phase negative sequence voltage, the fault phase negative-sequence current of T link three branch protection installation places first respectively; Calculate three branch roads respectively at the fault phase negative sequence voltage of T binding place, utilize Article 3 branch road to deduct the mean value of two other branch road in the fault phase negative sequence voltage sum of T binding place at the fault phase negative sequence voltage of T binding place, obtain voltage difference; Then whether the angle of calculating voltage difference leading Article 3 branch protection installation place fault phase negative-sequence current is less than zero and sets up, if set up, then judges that Article 3 branch road is the fault branch of T link.After the inventive method is applicable to T link unbalanced fault type and T link fault, the fault branch of whole failure process is selected, and selection result by the impact of transition resistance, load current and abort situation, accurately can not judge the fault branch of T link.

Description

Negative sequence component is utilized to realize the system of selection of T link fault branch

Technical field

The present invention relates to Relay Protection Technology in Power System field, specifically relate to one and utilize negative sequence component to realize the system of selection of T link fault branch.

Background technology

When land resource day is becoming tight, T link due to floor area little, cost is low, has become a kind of common multi-line power transmission mode of electric system.The electric parameters such as voltage transformer (VT), current transformer collecting device is not installed at the T binding place place of T link, after causing T link to break down, need first failure judgement point on any bar branch road of T link, and then utilize two ends of electric transmission line fault distance-finding method to carry out fault localization to abort situation.Therefore, to the correctness of fault branch selection result, direct relation the accuracy of T link localization of fault.

The system of selection of tradition T link fault branch utilizes the magnitude relationship Judging fault branch road of three branch roads between the voltage jump amount amplitude of T link T node.When trouble spot is near T link T node, affect by transition resistance, article three, branch road is very little in the voltage jump amount amplitude difference of T link T node, add the impact by voltage transformer (VT), current transformer progress of disease error and harmonic component, there will be fault branch and be less than the voltage jump amount amplitude of normal branch road at T link T node in the voltage jump amount amplitude of T link T node, cause traditional T link fault branch system of selection failure judgement branch road mistake, cause the failure of T link fault localization.

Summary of the invention

The object of the invention is to the deficiency overcoming prior art existence, provide a kind of negative sequence component that utilizes do not affected by transition resistance, load current and abort situation to realize the system of selection of T link fault branch.

For achieving the above object, the inventive method adopts following technical scheme:

Utilize negative sequence component to realize the system of selection of T link fault branch, comprise following sequential steps:

(1) protector measuring T link is at the fault phase negative sequence voltage of m end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in n end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in p end protection installation place fault phase negative-sequence current wherein, φ is A phase or B phase or C phase;

(2) protective device judges ${\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}+{\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that mt branch road is the fault branch of T link; Wherein, φ is A phase or B phase or C phase; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road;

(3) protective device judges ${\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2}+{\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that nt branch road is the fault branch of T link; Wherein, φ is A phase or B phase or C phase; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road;

(4) protective device judges ${\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}+{\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that pt branch road is the fault branch of T link; Wherein, φ is A phase or B phase or C phase; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road.

Beneficial effect of the present invention:

First the inventive method measures fault phase negative sequence voltage, the fault phase negative-sequence current of T link three branch protection installation places; calculate the fault phase negative sequence voltage of three branch roads at T binding place respectively; Article 3 branch road is utilized to deduct the mean value of two other branch road in the fault phase negative sequence voltage sum of T binding place at the fault phase negative sequence voltage of T binding place; obtain voltage difference; then whether the angle of calculating voltage difference leading Article 3 branch protection installation place fault phase negative-sequence current is less than zero and sets up; if set up, then judge that Article 3 branch road is the fault branch of T link.After the inventive method is applicable to T link unbalanced fault type and T link fault, the fault branch of whole failure process is selected, and selection result by the impact of transition resistance, load current and abort situation, accurately can not judge the fault branch of T link.

Accompanying drawing explanation

Fig. 1 is the T link transmission system schematic diagram of application the inventive method.

Embodiment

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

Fig. 1 is the T link transmission system schematic diagram of application the inventive method.In the present embodiment, three branch roads of T link are respectively mt branch road, nt branch road and pt branch road, and t is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads.Protector measuring T link is at the fault phase negative sequence voltage of m end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in n end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in p end protection installation place fault phase negative-sequence current wherein, φ is A phase or B phase or C phase.

Protective device judges ${\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}+{\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that mt branch road is the fault branch of T link.

Protective device judges ${\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2}+{\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that nt branch road is the fault branch of T link.

Protective device judges ${\stackrel{\·}{U}}_{\mathrm{p\φ}2}-l_{\mathrm{pt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{p\φ}2}-0.5({\stackrel{\·}{U}}_{\mathrm{n\φ}2}-l_{\mathrm{nt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{n\φ}2}+{\stackrel{\·}{U}}_{\mathrm{m\φ}2}-l_{\mathrm{mt}}{z}_1{\stackrel{\·}{I}}_{\mathrm{m\φ}2})$ Leading angle be less than zero and whether set up, if set up, then protective device judges that pt branch road is the fault branch of T link.

Wherein, φ is A phase or B phase or C phase; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road.

First the inventive method measures fault phase negative sequence voltage, the fault phase negative-sequence current of T link three branch protection installation places; calculate the fault phase negative sequence voltage of three branch roads at T binding place respectively; Article 3 branch road is utilized to deduct the mean value of two other branch road in the fault phase negative sequence voltage sum of T binding place at the fault phase negative sequence voltage of T binding place; obtain voltage difference; then whether the angle of calculating voltage difference leading Article 3 branch protection installation place fault phase negative-sequence current is less than zero and sets up; if set up, then judge that Article 3 branch road is the fault branch of T link.After the inventive method is applicable to T link unbalanced fault type and T link fault, the fault branch of whole failure process is selected, and selection result by the impact of transition resistance, load current and abort situation, accurately can not judge the fault branch of T link.

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. utilize negative sequence component to realize the system of selection of T link fault branch, it is characterized in that, comprise following sequential steps:

(1) protector measuring T link is at the fault phase negative sequence voltage of m end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in n end protection installation place fault phase negative-sequence current measure the fault phase negative sequence voltage of T link in p end protection installation place fault phase negative-sequence current wherein, φ is A phase or B phase or C phase;

(2) protective device judges leading angle be less than zero and whether set up, if set up, then protective device judges that mt branch road is the fault branch of T link; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road;

(3) protective device judges leading angle be less than zero and whether set up, if set up, then protective device judges that nt branch road is the fault branch of T link; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road;

(4) protective device judges leading angle be less than zero and whether set up, if set up, then protective device judges that pt branch road is the fault branch of T link; Three branch roads of T link are respectively mt branch road, nt branch road and pt branch road; T is the T binding place of three branch road mt branch roads, nt branch road and pt branch roads; z ₁for unit length electric transmission line positive sequence impedance; l _mtfor the length of T link mt branch road; l _ntfor the length of T link nt branch road; l _ptfor the length of T link pt branch road.