CN103207346A - Power transmission line fault phase selection method - Google Patents

Abstract

The invention discloses a power transmission line fault phase selection method. The method comprises firstly measuring the three-phase current sudden changes at the mounting position of a current transformer of a power transmission line in real time, and then performing the fault phase selection according to the fact that the ratio between each two changes has different mathematical characteristics under different types of power transmission line faults. The power transmission line fault phase selection method is provided with high phase selection sensitivity at a weak power side and even under the conditions that a single phase ground fault through highresistance occurs and the system operation mode changes a lot, thereby being capable of providing correct and accurate fault phase information for distance protection and the correct action of automatic reclosing.

Description

The transmission line malfunction phase-selecting method

Technical field

The present invention relates to electric power system fault and select the phase technical field, specifically relate to a kind of transmission line malfunction phase-selecting method.

Background technology

Sudden change amount phase-selecting method comprises that difference of phase currents selects phase, the choosing of phase voltage sudden change amount mutually and the comprehensive phase-selecting method of electric current and voltage sudden change amount.At the light current source, difference of phase currents selects phase insufficient sensitivity height; At the forceful electric power source, it is not enough that phase voltage sudden change amount selects phase sensitivity to exist; Better select sensitivity mutually though the comprehensive phase-selecting method of electric current and voltage sudden change amount all has at light current source and forceful electric power source, select in three phase short circuit fault that sensitivity exists not enough aspect the phase.

Transmission line malfunction selects correct operation that the phase correctness concerning transmission line distance protecting and auto recloser whether; has very material impact to strengthening relay protection of transmission line action correctness and reliability; therefore, research is a kind of takes place all have enough height under the big situation of change at single-phase high resistance ground, light current source and system operation mode and selects the transmission line malfunction phase-selecting method of sensitivity mutually to have very important meaning.

Summary of the invention

The objective of the invention is to overcome the deficiency that prior art exists, provide a kind of and take place all have the transmission line malfunction phase-selecting method that enough height select sensitivity mutually under the big situation of change at single-phase high resistance ground, light current source and system operation mode.

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

The transmission line malfunction phase-selecting method, its main points are, include following steps:

(1) provides a kind of protective device, A, B, the C difference of phase currents of this protector measuring transmission line of electricity current transformer installation place

(2) protective device calculates according to its electric parameters that measures

With

And set setting valve ξ, carry out fault according to following criterion then and select phase;

(3) if satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}>\mathrm{\ξ}$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}>\mathrm{\ξ},$ Then be judged as transmission line of electricity A phase earth fault;

If satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}=1$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}>\mathrm{\ξ}$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}>\mathrm{\ξ},$ Then be judged as transmission line of electricity B phase earth fault;

If satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}>\mathrm{\ξ}$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}>\mathrm{\ξ}$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1,$ Then be judged as transmission line of electricity C phase earth fault;

(4) if satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}=2$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=2,$ Then be judged as transmission line of electricity BC phase-to phase fault;

If satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}=2$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}=2$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase-to phase fault;

If satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=2$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}=2$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase-to phase fault;

(5) if satisfy $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}=1$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_A-\mathrm{\Δ}{\stackrel{\·}{I}}_B|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1$ And $\frac{|\mathrm{\Δ}{\stackrel{\·}{I}}_B-\mathrm{\Δ}{\stackrel{\·}{I}}_C|}{|\mathrm{\Δ}{\stackrel{\·}{I}}_C-\mathrm{\Δ}{\stackrel{\·}{I}}_A|}=1,$ Then be judged as transmission line of electricity ABC fault;

(6) if satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2,$ Then be judged as transmission line of electricity BC phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase fault earth fault again.

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

The inventive method has different mathematical features according to the ratio in twos of difference between the three-phase current sudden change amount and carries out fault and select phase under different transmission line malfunction types; the inventive method all has the sufficiently high sensitivity mutually of selecting under single-phase high resistance ground, light current source and system operation mode take place than big situation of change, can be distance protection and automatic reclosing correct operation correct fault phase information reliably is provided.

Description of drawings

Fig. 1 is for using circuit transmission system synoptic diagram of the present invention.

Embodiment

According to Figure of description technical scheme of the present invention is done further detailed presentations below.

Fig. 1 is for using circuit transmission system synoptic diagram of the present invention.Protective device is measured A, B, the C three-phase current sudden change amount of transmission line of electricity current transformer installation place in real time

Calculate

With

Set setting valve ξ.

Utilize

With

Between in twos ratio under different transmission line malfunction types, have different mathematical features and carry out fault and select phase, concrete fault selects the phase criterion as follows:

(1) if satisfies $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}>\mathrm{\&xi;},$ Then be judged as transmission line of electricity A phase earth fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}>\mathrm{\&xi;},$ Then be judged as transmission line of electricity B phase earth fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity C phase earth fault;

(2) if satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=2,$ Then be judged as transmission line of electricity BC phase-to phase fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase-to phase fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase-to phase fault;

(3) if satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity ABC fault;

(4) if satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2,$ Then be judged as transmission line of electricity BC phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase fault earth fault again.

The inventive method has different mathematical features according to the ratio in twos of difference between the three-phase current sudden change amount and carries out fault and select phase under different transmission line malfunction types; the inventive method all has the sufficiently high sensitivity mutually of selecting under single-phase high resistance ground, light current source and system operation mode take place than big situation of change, can be distance protection and automatic reclosing correct operation correct fault phase information reliably is provided.

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

Claims (1)

1. the transmission line malfunction phase-selecting method is characterized in that, comprises the steps:

(1) provides a kind of protective device, A, B, the C difference of phase currents of this protector measuring transmission line of electricity current transformer installation place

(2) protective device calculates according to its electric parameters that measures

With

And set setting valve ξ, carry out fault according to following criterion then and select phase;

(3) if satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}>\mathrm{\&xi;},$ Then be judged as transmission line of electricity A phase earth fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}>\mathrm{\&xi;},$ Then be judged as transmission line of electricity B phase earth fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}>\mathrm{\&xi;}$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity C phase earth fault;

(4) if satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=2,$ Then be judged as transmission line of electricity BC phase-to phase fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase-to phase fault;

If satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}=2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase-to phase fault;

(5) if satisfy $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity ABC fault;

(6) if satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2,$ Then be judged as transmission line of electricity BC phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}=1,$ Then be judged as transmission line of electricity CA phase fault earth fault again;

If satisfy $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}<2$ And $\sqrt{3}<\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}<2$ And $\frac{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_B-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C|}{|\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_C-\mathrm{\&Delta;}{\stackrel{\&CenterDot;}{I}}_A|}=1,$ Then be judged as transmission line of electricity AB phase fault earth fault again.

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