CN107394757B - A kind of preceding fault-free recognition methods of power distribution network phase-to phase fault coincidence - Google Patents
A kind of preceding fault-free recognition methods of power distribution network phase-to phase fault coincidence Download PDFInfo
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- CN107394757B CN107394757B CN201710824220.XA CN201710824220A CN107394757B CN 107394757 B CN107394757 B CN 107394757B CN 201710824220 A CN201710824220 A CN 201710824220A CN 107394757 B CN107394757 B CN 107394757B
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- 238000010891 electric arc Methods 0.000 description 7
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
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- Locating Faults (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The present invention discloses a kind of preceding fault-free recognition methods of power distribution network phase-to phase fault coincidence: the three-phase voltage instantaneous sampling value u of acquisition route lines in parallel compensation capacitor between failure acquires between being overlapped early period and is extremely overlapped early period after distribution network line breaks downφ(k), route beginning phase current iφ_l(k), shunt capacitor phase current iφ_c(k), phase voltage difference u is calculatedφφ(k), route phase current iφ(k), phase differential current iφφ(k) and its simultaneously first-order difference value di is calculatedφφ(k), wherein φ=A, B, C；Utilize phase voltage difference uφφ(k) and phase differential current iφφ(k) equation u is identifiedφφ(k)=Rf.Aφφ1(k)+p.Aφφ2(k) fault loop substitutional resistance R is calculatedfWith fault distance p parameter, data window is then sequentially elapsed, obtains the sequence of identified parametersFault-free identical criterion before being overlapped using phase-to phase faultIt carries out malfunction identification and is then judged to alternate transient fault and failure blow-out, reclosing multiple action when criterion is persistently set up；If criterion is invalid, lasting judgement differentiates that the time reaches up to maximum, is judged to permanent fault at this time, reclosing is not overlapped.The present invention effectively improves the success rate of alternate coincidence.
Description
Technical field
The present invention relates to system for distribution network of power relay protection field more particularly to a kind of distribution line phase-to phase fault weights
Fault-free recognition methods before closing.
Background technique
It is most in the short trouble (including the single-line to ground fault in small current neutral grounding system) of China's power distribution network
(70%~90%) is transient fault, can eliminate power distribution network overwhelming majority transient fault using automatic reclosing to mention
Distribution network reliability when high phase-to phase fault.But fault electric arc when for part transient fault (arc resistance failure) due to being overlapped
Not extinguishing will lead to unsuccessful reclosing.Therefore, the identification of unfaulty conditions avoids coinciding with substantive permanent fault before being overlapped
It is of great significance for distribution network line reclosing successful reclosing rate.
China's electric system is influenced by " weight Generation Side, light confession/distribution side " idea for a long time, and distribution protection scheme is often
It only emphasizes to guarantee the safety of power grid itself and simplifies relaying configuration, usually only need substation exit side and load end side
It configures three-step charging and uses single reclosing mode.When Distribution Network Frame abortive haul network phase-to phase fault, protection act tripping,
Close a floodgate again through constant time lag, if close a floodgate when transient fault disappear and insulation recovery normally if closing success continue to power；It is another
Aspect is closed a floodgate if fault point does not disappear in second short circuit when closing a floodgate, and trips no longer be overlapped again, especially once outlet is protected
Tripping means that whole appearance or branch line all have a power failure again, and scope of power outage is big and the time that restores electricity is long.Power distribution network at present
Phase-to phase fault using arc resistance failure as principal mode, on the one hand blow-out is directly resulted in using definite-time coincidence system slow
Arc resistance failure reclosing failure, and coincides with the similar of permanent fault, second short circuit will be brought to impact to system；On the other hand right
In the quick arc resistance failure of blow-out, then the open-phase operation time will be extended, and be equivalent to and artificially extend power off time.
Summary of the invention
It is overlapped preceding fault-free recognition methods using power distribution network phase-to phase fault the purpose of the present invention is to provide a kind of, to solve
Above-mentioned technical problem.The present invention utilizes end voltage, electric current and the route beginning current information of power distribution network parallel capacitor
The calculating of electric arc substitutional resistance when progress phase-to phase fault is realized using the amplitude and variation characteristic of arc resistance to alternate electric arc
The capture at failure and blow-out moment, to realize that power distribution network phase-to phase fault property identification provides good thinking.The present invention is abundant
Using the temporal signatures of the voltage of parallel capacitor, electric current after the tripping of power distribution network phase-to phase fault three-phase, establishes failure phase and return
The identification equation about arc resistance and abort situation on road is carried out according to the amplitude of the arc resistance of calculating and change rate feature
On the other hand nature of trouble identification, the alternate arc resistance failure of one side reliable recognition accurately capture transient fault blow-out
Moment, and then realize the reliable recognition of unfaulty conditions before alternate coincidence, for the adaptive reclosing technology for realizing phase-to phase fault
Important evidence is provided.
In order to achieve the above object, the present invention is achieved by the following scheme:
A kind of preceding fault-free recognition methods of power distribution network phase-to phase fault coincidence, comprising the following steps:
(1) to the three-phase voltage wink of lines in parallel compensation capacitor between coincidence early period after acquisition distribution network line breaks down
When sampled value uφ(k), route beginning three-phase current iφ_l(k), shunt capacitor group three-phase current iφ_c(k), it is poor to calculate phase voltage
uφφ(k), route phase current iφ(k)=[iφ_l(k)-iφ_c(k)], phase differential current iφφ(k) and its first-order difference diφφ(k)=
[iφφ(k)-iφφ(k-1)]/Ts；Wherein φ=A, B, C, TsFor the sampling period；
(2) phase voltage difference u is utilizedφφ(k) and phase differential current iφφ(k) construction is about fault loop substitutional resistance RfAnd failure
Distance p parameter identifies equation uφφ(k)=Rf.Aφφ1(k)+p.Aφφ2(k), wherein Aφφ1(k)、Aφφ2(k) for by iφφ(k)、
diφφ(k) and route impedance Rl, inductance LlIt determines, establishes redundant equation group with the data redundancy data window of 5ms and calculate failure
Circuit substitutional resistance RfWith fault distance p, data window is then sequentially elapsed, obtains the sequence of identified parameters
(3) fault-free identical criterion before being overlapped using phase-to phase faultMalfunction examination is carried out, when criterion is held
When continuous establishment, then alternate transient fault is judged to and failure blow-out, reclosing multiple action；If criterion is invalid,
Lasting judgement differentiates that the time reaches up to maximum, is judged to permanent fault at this time, reclosing is not overlapped；
Wherein,M is calculated result sequence length；RsetTo adjust threshold.
Further, m takes 10~20.
Further, RsetTake the Ω of 50 Ω~100.
Further, Aφφ1(k)=0.5iφφ(k), Aφφ2(k)=[Rl.iφφ(k)+Ll.diφφ(k)]。
The present invention proposes that a kind of power distribution network phase-to phase fault is overlapped fault-free method of discrimination, makes full use of fault electric arc to coincidence
The fault signature of period constructs the identical criterion using electric arc circuit substitutional resistance feature, improves the alternate event of existing power distribution network
The adaptive ability for hindering reclosing, further increases the success rate of alternate coincidence.
Compared with prior art, there is following remarkable advantage:
(1) fault characteristic information after power distribution network phase-to phase fault to before being overlapped is made full use of.
(2) this method is conducive to using the effective identification for being able to carry out the malfunction before power distribution network phase-to phase fault is overlapped
Improve the success rate being overlapped.
Detailed description of the invention
Fig. 1 is power distribution network BC phase-to phase fault equivalent network；
Fault-free identification process figure before being overlapped when Fig. 2 is power distribution network phase-to phase fault；
Specific embodiment
It please refers to shown in Fig. 1 to Fig. 2, fault-free recognition methods before a kind of power distribution network phase-to phase fault of the present invention is overlapped, including
Following steps:
(1) calculating of three-phase electrical quantity acquisition and characteristic quantity
Power distribution network bus bar side voltage transformer secondary side voltage in Fig. 1 is by low-pass filtering, sampling holding processing, acquisition
Distribution network line is extremely overlapped the three-phase voltage instantaneous value u of lines in parallel compensation capacitor between early period after breaking downφ(k)(uA
(k)、uB(k)、uC(k)), three-phase line beginning electric current iφ_l(k)(iA_l(k)、iB_l(k)、iC_l(k)), three phase parallel capacitor
Phase current iφ_c(k)(iA_c(k)、iB_c(k)、iC_c(k)) phase voltage difference u, is calculatedφφ(k)(uAB(k)=uA(k)-uB(k)、uBC
(k)=uB(k)-uC(k)、uCA(k)=uC(k)-uA(k)), phase current residual quantity iφφ(k)(iAB(k)=[iA_l(k)-iA_c(k)]-
[iB_l(k)-iB_c(k)]、iBC(k)=[iB_l(k)-iB_c(k)]-[iC_l(k)-iC_c(k)]、iCA(k)=[iC_l(k)-iA_c
(k)]-[iA_l(k)-iA_c(k)]).Wherein φ=A, B, C.The first-order difference di of three-phase spill current is calculated simultaneouslyφφ(k)=[iφφ
(k)-iφφ(k-1)]/Ts(diAB(k)=[iAB(k)-iAB(k-1)]/Ts, diBC(k)=[iBC(k)-iBC(k-1)]/Ts、diCA
(k)=[iCA(k)-iCA(k-1)]/Ts).In formula, TsFor the sampling period.
(2) fault loop substitutional resistance RfWith the identification of fault distance p parameter
According to fault loop substitutional resistance R under phase voltage difference and phase differential current construction continued time domainfWith fault distance p parameter
Identification equation:
Establish the parameter linear identification equation group u under its discrete sample signalsφφ(k)=Rf.Aφφ1(k)+p.Aφφ2(k)
(φ=A, B, C),
Aφφ1(k)、Aφφ2(k) for by iφφ(k)、diφφ(k) and route impedance Rl, inductance LlIt determines: Aφφ1(k)=
0.5iφφ(k), Aφφ2(k)=[Rl.iφφ(k)+Ll.diφφ(k)]。
Redundant equation group is established using the redundant data window under the sample variance data of 5ms and calculates fault loop substitutional resistance
RfWith fault distance p, i.e., an estimates of parameters is obtained with the sampled value of a period of time, that is, be described as shaped like [Rf,p].[Aφφ1,
Aφφ2]T=[uφφ] redundant equation,
Then data window is sequentially elapsed, the sequence of identified parameters is obtained
Formula (2), k0To calculate data starting point, N is power frequency period sampling number.
It is illustrated by taking power distribution network BC phase-to phase fault shown in Fig. 2 as an example.It corresponds to the failure Xiang Duan electricity under continued time domain
Relationship is as follows between pressure, electric current
uB(t)=p.Rl.iB(t)+p.Ll.diB(t)/dt+ukB(t) (3)
uC(t)=p.Rl.iC(t)+p.Ll.diC(t)/dt+ukC(t) (4)
In formula (3), formula (4), ukB(t)、ukBIt (t) is respectively B phase, C phase fault point voltage.
By above (3), (4) Shi Ke get:
ukBC(t)=ukB(t)-ukC(t)
=[uB(t)-uC(t)]-[p.Rl.(iB(t)-iC(t))+p.Ll.(diB(t)/dt-diC(t)/dt)] (5)
=uBC(t)-p.Rl.iBC(t)-p.Ll.diBC(t)/dt
ukBC(t)=ukB(t)-ukC(t)=Rf.iB(t)=0.5Rf.iBC(t) (6)
In formula (5), ukBC(t) poor for phase-to phase fault loop voltage.
It can be obtained by formula (5), (6)
uBC(t)-p.Rl.iBC(t)-p.Ll.diBC(t)/dt=0.5Rf.iBC(t) (7)
Arrange to obtain formula (8)
uBC(t)=p.Rl.iBC(t)+p.Ll.diBC(t)/dt+0.5Rf.iBC(t)
=Rf.[0.5iBC(t)]+p.[Rl.iBC(t)+Ll.diBC(t)/dt] (8)
=Rf.ABC1(t)+p.ABC2(t)
It just can be obtained shaped like parameter identification equation shown in formula (1) using corresponding discrete sample signals, establish phase later
The redundant equation answered calculates the sequence of identified parameters
(3) fault-free identification before phase-to phase fault is overlapped
There is nonlinearity feature in its fault electric arc circuit substitutional resistance of arcing phase, and most electric arcs can
It is instantaneous to extinguish；And substantive permanent fault (as broken) is approximately a stationary value in its transition resistance, feature can realize electricity accordingly
The differentiation of arc transient fault and substantive permanent fault.In addition, arc resistance failure after arc extinction, is equivalent to through infinite serious offense
The permanent fault of resistance is crossed, transition resistance value and arcing phase calculated value significant difference is calculated, utilizes fault electric arc circuit etc.
Value resistance calculations value also can be realized property judgment.
Upper feature construction hinders identical criterion accordinglyMalfunction examination is carried out, whereinm
For calculated result sequence length, it can use 10~20；RsetTo adjust threshold, can adjust as 50~100 Ω.When criterion is persistently set up
When, then it is judged to alternate transient fault and failure blow-out, reclosing multiple action；If criterion is invalid, persistently sentence
It is disconnected to differentiate that the time reaches up to maximum, it is judged to permanent fault at this time, reclosing is not overlapped.In addition, can also be using combination originally
The calculated result of abort situation in method carries out the confirmation that position occurs for distribution network failure.
Fault-free recognition methods before power distribution network phase-to phase fault proposed by the present invention is overlapped, first with route beginning electric current,
The voltage and current temporal signatures of shunt capacitor group carry out the identification of fault loop substitutional resistance, utilize distinguishing for substitutional resistance
Know the identification that result carries out phase-to phase fault state, provides important evidence to implement the coincidence of phase-to phase fault fault-free.This method tool
There is the advantages that simple possible, calculation amount is small, fault-free before the phase-to phase fault suitable for the power distribution network with shunt capacitor group is overlapped
Identification.
Claims (4)
- Fault-free recognition methods before 1. a kind of power distribution network phase-to phase fault is overlapped, which comprises the following steps:(1) it is instantaneously adopted after acquisition distribution network line breaks down to the three-phase voltage of lines in parallel compensation capacitor between coincidence early period Sample value uφ(k), route beginning three-phase current iφ_l(k), shunt capacitor group three-phase current iφ_c(k), phase voltage difference u is calculatedφφ (k), route phase current iφ(k)=[iφ_l(k)-iφ_c(k)], phase differential current iφφ(k) and its first-order difference diφφ(k)=[iφφ (k)-iφφ(k-1)]/Ts；Wherein φ=A, B, C, TsFor the sampling period；(2) phase voltage difference u is utilizedφφ(k) and phase differential current iφφ(k) construction is about fault loop substitutional resistance RfWith fault distance p Parameter identifies equation uφφ(k)=Rf.Aφφ1(k)+p.Aφφ2(k), wherein Aφφ1(k)、Aφφ2(k) by iφφ(k)、diφφ(k) with And route impedance Rl, inductance LlIt determines, establishes redundant equation group with the data redundancy data window of 5ms and calculate fault loop equivalence Resistance RfWith fault distance p, data window is then sequentially elapsed, obtains the sequence of identified parameters(3) fault-free identical criterion before being overlapped using phase-to phase faultCarry out malfunction examination, when criterion continue at Immediately, then it is judged to alternate transient fault and failure blow-out, reclosing multiple action；If criterion is invalid, continue Judgement is judged to permanent fault, reclosing is not overlapped until maximum differentiation time arrival at this time；Wherein,M is calculated result sequence length；RsetTo adjust threshold.
- Fault-free recognition methods before 2. a kind of power distribution network phase-to phase fault according to claim 1 is overlapped, which is characterized in that m Take 10~20.
- Fault-free recognition methods before 3. a kind of power distribution network phase-to phase fault according to claim 1 is overlapped, which is characterized in that RsetTake the Ω of 50 Ω~100.
- Fault-free recognition methods before 4. a kind of power distribution network phase-to phase fault according to claim 1 is overlapped, which is characterized in that Aφφ1(k)=0.5iφφ(k), Aφφ2(k)=[Rl.iφφ(k)+Ll.diφφ(k)]。
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| CN108899864B (en) * | 2018-06-21 | 2019-07-30 | 许继电气股份有限公司 | The adaptive reclosing method of distribution line and nature of trouble recognition methods |
| CN111157844A (en) * | 2020-01-06 | 2020-05-15 | 许昌许继软件技术有限公司 | Distribution line self-adaptive reclosing method and fault property identification method and device |
| CN112332385B (en) * | 2020-10-28 | 2022-07-12 | 西安工程大学 | Detection type permanent fault discrimination method before inter-phase coincidence of power distribution network |
| CN112909901B (en) * | 2021-01-25 | 2022-09-09 | 南京国电南自电网自动化有限公司 | Power distribution network line adaptive reclosing method and storage medium |
| CN114280499A (en) * | 2021-12-21 | 2022-04-05 | 国能榆林能源有限责任公司 | Electric leakage detection method for coal mine underground power supply system and coal mine underground power supply system |
| CN117239670B (en) * | 2023-11-14 | 2024-01-26 | 昆明理工大学 | Single-phase self-adaptive reclosing method and system for wind power alternating current outgoing line |
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| CN101316036B (en) * | 2008-07-16 | 2011-06-08 | 天津大学 | Self-adapting three-phase reclosure decision method of ultra-high voltage electric power line with shunt reactor |
| CN101860000B (en) * | 2010-05-14 | 2012-06-13 | 河南电力试验研究院 | Quick identification method for permanent fault before single-phase reclosing of power transmission line |
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