CN102096022A - Traveling wave failure distance measurement method for electric power circuit - Google Patents

Abstract

The invention provides a traveling wave failure distance measurement method for an electric power circuit, which comprises the following steps of: (1) measuring initially, namely measuring time difference delta T that an initial traveling wave surge caused by a failure reaches both ends M and N of the circuit when the circuit fails internally, and solving the distance from a bus at the M end to a failure point F, wherein L is the length of the circuit, v is the propagation velocity of a traveling wave, the delta T is equal to the difference of TM and TN and the distance is used as a reference value; and (2) verifying and correcting, namely measuring time difference delta t between a first forward traveling wave surge of the bus at the M end and a reflection traveling wave surge of the failure point after the failure occurs, and solving the distance from the bus to the failure point F, wherein if delta D which is equal to the absolute value of (DMF-DMF*) is less than or equal to 1 kilometer, the distance from the bus at the M end to the failure point F is DMF*, and if the delta D is more than 1 kilometer, the distance from the bus at the M end to the failure point F is DMF. By the method, the traveling wave failure distance measurement of the electric power circuit is realized, and the reliability and the accuracy of the traveling wave distance measurement are improved; and after the failure of the circuit occurs, the failure point can be determined without the searching for a long time, so the power supply reliability is improved, and the method has a wide application prospect.

Description

Power circuit traveling wave fault location method

Technical field

The invention belongs to the protecting electrical power system technical field, particularly a kind of power circuit traveling wave fault location method.

Background technology

Determine the position of failure point of power circuit quickly and accurately, can accelerate the reparation of permanent fault, in time remove a hidden danger, safety and stability and the economical operation that guarantees electric system had crucial meaning to avoid the generation once more of a large amount of transient faults.

Power circuit traveling wave fault location technology is paid close attention to by the relay protection professional because of having advantages such as distance accuracy is high and applied widely always.As far back as the 1950's, just develop the traveling wave fault location device of basic patterns such as A, B, C, D abroad, but, do not applied eventually because of there being problems such as poor reliability, formation is complicated and cost an arm and a leg.

The eighties in 20th century, both at home and abroad in early days on the basis of A type travelling wave ranging principle, proposed collection protection and range finding for the capable pitch of waves of one from protection philosophy.But because location algorithm is unreliable and the restriction of site test condition, the row pitch of waves is not further developed from protection.

Early 1990s, China has proposed to utilize the modern traveling wave fault location technology of current temporary state component, thereby has promoted the commercialized development of power circuit travelling wave ranging technology.

Theoretical analysis and practical application show that although the capable ripple principle of D type both-end can on-line automaticly provide the range finding result, its reliability and accuracy are subjected to the influence of given line length and time dissemination system.When given line length exists when undesired than mistake or time dissemination system work, D type travelling wave ranging result is incredible.On the other hand, although A type single-ended traveling wave principle has higher accuracy, be difficult to provide automatically correct range finding result owing to location algorithm is immature.As seen, all there are certain defective in the existing A type single-ended traveling wave principle and the travelling wave ranging of the capable ripple principle of D type both-end.

Summary of the invention

The object of the present invention is to provide a kind of accurate traveling wave fault location method that can overcome above-mentioned defective, be applicable to power circuit.Its technical scheme is:

A kind of power circuit traveling wave fault location method is characterized in that adopting following steps:

(1) preliminary survey: represent Route Length with L, v represents the row velocity of wave propagation, and during the line-internal fault, the initial row wave of measuring the fault generation is rushed to the mistiming Δ T=T that reaches circuit two ends M, N _M-T _N, try to achieve M and hold bus to be to the distance of trouble spot F And with D _MFAs reference value;

(2) checking and revise: measure first direct wave and the mistiming Δ t between the F reflected traveling wave of trouble spot of recording after fault produces, try to achieve M and hold the distance of bus to trouble spot F

If Δ D=|D _MF-D _MF ^*|≤1km, assert that then M end bus is D to the distance of trouble spot F _MF ^*, otherwise assert that M end bus is D to the distance of trouble spot F _MF

Realize the another kind of power circuit traveling wave fault location method of the object of the invention, it is characterized in that adopting following steps:

(1) preliminary survey: represent Route Length with L, v represents the row velocity of wave propagation, and during the line-internal fault, the initial row wave of measuring the fault generation is rushed to the mistiming Δ T=T that reaches circuit two ends M, N _M-T _N, try to achieve N and hold bus to be to the distance of trouble spot F

And with D _NFAs reference value;

(2) checking and revise: measure fault and produce mistiming Δ t ' between the N end bus reflection wave that first backward-travelling wave that back M end records and trouble spot F transmission come, try to achieve N and hold the distance of bus to trouble spot F

If Δ D=|D _NF-D _NF ^*|≤1km, assert that then N end bus is D to the distance of trouble spot F _NF ^*, otherwise assert that N end bus is D to the distance of trouble spot F _NF

Principle of work is: for the capable ripple principle of D type, its reliability and accuracy are subjected to the influence of given line length and time dissemination system.When given line length exists when undesired than mistake or time dissemination system work, D type travelling wave ranging result is incredible.Although A type single-ended traveling wave principle has higher accuracy, be difficult to provide automatically correct range finding result owing to location algorithm is immature.A type single-ended traveling wave principle and the capable ripple principle of D type both-end are optimized combination, utilize the accuracy of A type single-ended traveling wave principle, the reliability of D type single-ended traveling wave principle, carry out bigness scale with D type both-end principle, carry out verification with A type principle, can improve the reliability and the accuracy of fault localization largely.

The present invention has compared with prior art improved the reliability and the accuracy of power circuit traveling wave fault location largely.Behind line failure, need not the expensive time to get final product the localization of faults, improved power supply reliability, have a extensive future.

Description of drawings

Fig. 1 is a fault transient travelling wave communication process of the present invention.

Fig. 2 is the fault traveling wave surge that the M termination is received in the running example.

Fig. 3 is the fault traveling wave surge that the N termination is received in the running example.

Among the figure: T _MAnd T _NBe respectively fault initial row wave and be rushed to the moment that reaches M end and N end measurement point, T _M2And T _N2Being respectively fault initial row wave gushes by the moment that arrives M end and N end measurement point after the reflection once of trouble spot again, T ' _M2And T ' _N2Be respectively fault initial row wave and gush the moment that once arrives M end and N end measurement point by the reflection of opposite end bus.

Embodiment

The present invention is made the following instructions with certain running example below in conjunction with accompanying drawing:

B phase earth fault takes place in certain 220kV circuit MN, and the transient state travelling wave current waveform at circuit two ends (sample frequency is 1MHz) is respectively shown in Fig. 2,3.Length L=the 64.3km of known line, row velocity of wave propagation v=297m/ μ s.

Step 1, preliminary survey: circuit two ends measurement point is experienced the moment (microsecond number) that fault initial row wave gushes and is respectively T _M=680652 μ s, T _N=680617 μ s, M end bus to the distance of trouble spot F is

N end bus is to the distance of trouble spot F

And with D _MF, D _NFAs reference value;

Step 2, checking and revise: measure fault first direct wave that back M end records and the mistiming t=248 μ s between the F reflected traveling wave of trouble spot take place, measure the mistiming t '=184 μ s between the N end bus reflection wave that the M end records after the fault first backward-travelling wave and trouble spot F transmission come, try to achieve M and hold the distance of bus to trouble spot F

N end bus is to the distance of trouble spot F

Because Δ D=|D _MF-D _MF ^*|=0.5km≤1km (or Δ D=|D _NF-D _NF ^*|=0.4km≤1km), assert that then trouble spot F is respectively 36.8km and 27.3km apart from M end bus and N end bus.

Empirical tests physical fault point is apart from M end 37km, and the bigness scale error is 300m, and the error after the correction is 200m.

Claims (2)

1. power circuit traveling wave fault location method is characterized in that adopting following steps:

(1) preliminary survey: represent Route Length with L, v represents the row velocity of wave propagation, and during the line-internal fault, the initial row wave of measuring the fault generation is rushed to the mistiming Δ T=T that reaches circuit two ends M, N _M-T _N, try to achieve M and hold bus to be to the distance of trouble spot F And with D _MFAs reference value;

(2) checking and revise: measure first direct wave and the mistiming Δ t between the F reflected traveling wave of trouble spot of recording after fault produces, try to achieve M and hold the distance of bus to trouble spot F

If Δ D=|D _MF-D _MF ^*|≤1km, assert that then M end bus is D to the distance of trouble spot F _MF ^*, otherwise assert that M end bus is D to the distance of trouble spot F _MF

2. power circuit traveling wave fault location method is characterized in that adopting following steps:

(1) preliminary survey: represent Route Length with L, v represents the row velocity of wave propagation, and during the line-internal fault, the initial row wave of measuring the fault generation is rushed to the mistiming Δ T=T that reaches circuit two ends M, N _M-T _N, try to achieve N and hold bus to be to the distance of trouble spot F

And with D _NFAs reference value;

(2) checking and revise: measure fault and produce mistiming Δ t ' between the N end bus reflection wave that first backward-travelling wave that back M end records and trouble spot F transmission come, try to achieve N and hold the distance of bus to trouble spot F

If Δ D=|D _NF-D _NF ^*|≤1km, assert that then N end bus is D to the distance of trouble spot F _NF ^*, otherwise assert that N end bus is D to the distance of trouble spot F _NF

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