CN111896842A - Power distribution network arc high-resistance fault section positioning method based on interval slope - Google Patents

Power distribution network arc high-resistance fault section positioning method based on interval slope Download PDF

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Publication number
CN111896842A
CN111896842A CN202010732977.8A CN202010732977A CN111896842A CN 111896842 A CN111896842 A CN 111896842A CN 202010732977 A CN202010732977 A CN 202010732977A CN 111896842 A CN111896842 A CN 111896842A
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fault
interval
positioning
slope
arc high
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Inventor
谢伟
张恒旭
杨建平
石访
朱征
张弛
方陈
时志雄
刘舒
韦明杰
沈冰
鲍伟
魏新迟
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Shandong University
State Grid Shanghai Electric Power Co Ltd
East China Power Test and Research Institute Co Ltd
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Shandong University
State Grid Shanghai Electric Power Co Ltd
East China Power Test and Research Institute Co Ltd
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Priority to AU2020327344A priority patent/AU2020327344B2/en
Priority to PCT/CN2020/135704 priority patent/WO2022021740A1/en
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08Locating faults in cables, transmission lines, or networks
    • G01R31/081Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08Locating faults in cables, transmission lines, or networks
    • G01R31/088Aspects of digital computing
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52Outage or fault management, e.g. fault detection or location

Abstract

The invention relates to a power distribution network arc high-resistance fault section positioning method based on interval slope, which comprises a fault detection process and a fault positioning process, wherein in the fault detection process, a corresponding interval slope absolute value is obtained according to collected zero-sequence current, whether each period of the zero-sequence current has arc high-resistance fault characteristics or not is sequentially judged based on the interval slope absolute value, the period with the arc high-resistance fault characteristics is recorded as a fault period, and when the continuous number of the fault periods is greater than a set value, the fault positioning process is started; in the fault positioning process, fault section positioning is carried out based on the synchronous zero-sequence current and the zero-sequence voltage waveform of each measuring point. Compared with the prior art, the method has the advantages of reliability, effectiveness and the like.

Description

Power distribution network arc high-resistance fault section positioning method based on interval slope
Technical Field
The invention relates to a power distribution network fault positioning method, in particular to a power distribution network arc light high-resistance fault section positioning method based on an interval slope.
Background
Arc high resistance fault is a common fault form of a power distribution network, and generally, an overhead line is in contact with a high-impedance grounding medium due to disconnection/falling to the ground or tree obstacles, so that a single-phase grounding fault is formed. Common high-impedance grounding media comprise cement, sand, soil, rubber, asphalt, trees and the like, the fault resistance is different from hundreds of ohms to dozens of kilohms, the fault current is extremely weak even within 1 ampere, and therefore the traditional overcurrent protection device of the power distribution network and the like are difficult to detect. Because a reliable connection cannot be made between the wire and the ground medium and an air gap is present all the time (except for water resistance), high resistance faults often achieve electrical connection of the line conductor and the ground medium with an arc. The long-term existence of the arc high-resistance fault easily causes fire, and brings great threat to the safety of personnel and facilities. The extremely weak characteristics of the fault, the interference of load current and background noise, the nonlinearity of the arc, the difference of the nonlinearity under different grounding media and the like all bring challenges to the reliable detection and accurate positioning of the fault.
High resistance faults generally result from contact of the conductor with a high impedance grounded medium caused by an overhead line break or a tree break, which is generally unreliable, and air gaps are commonly present between the conductor and the grounded medium or within the grounded medium. Therefore, when a high-resistance ground fault occurs, the high-resistance ground fault is generally electrically connected with the ground through an arc forming network, so that nonlinear waveform distortion is generated in both fault current and zero-sequence current. The waveform distortion of the zero sequence current can be described by a slope. However, calculating the slope directly by derivation or difference is clearly highly susceptible to signal noise, which may result from background noise, measurement errors, or invalid distortions due to arcing.
Therefore, accurate and quick section positioning of the fault is an important aspect for improving the power supply reliability of the power distribution network.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a reliable and effective method for positioning the arc high-resistance fault section of the power distribution network based on the interval slope.
The purpose of the invention can be realized by the following technical scheme:
a power distribution network arc high resistance fault section positioning method based on interval slope comprises a fault detection process and a fault positioning process,
in the fault detection process, acquiring a corresponding interval slope absolute value according to the acquired zero sequence current, sequentially judging whether each period of the zero sequence current has arc high-resistance fault characteristics or not based on the interval slope absolute value, recording the periods with the arc high-resistance fault characteristics as fault periods, and starting the fault positioning process when the continuous number of the fault periods is greater than a set value;
in the fault positioning process, fault section positioning is carried out based on the synchronous zero-sequence current and the zero-sequence voltage waveform of each measuring point.
Further, the fault detection process includes the following steps:
11) acquiring zero sequence current, obtaining the maximum and minimum values of the current for each period of the zero sequence current, and positioning to the minimum value point N of the interval slope absolute value corresponding to the period based on the maximum and minimum values of the current1And N2And will be the point N of the previous cycle2As N0Composition interval [ N0,N2];
12) For half period interval [ N0,N1]Obtaining the minimum value point nminJudging whether the minimum value point simultaneously meets the following two criteria, if so, executing the step 13), otherwise, returning to the step 11) to judge the next period:
a) demarcating the first nminIs nmin0Which satisfies:
Figure BDA0002603866530000021
wherein the content of the first and second substances,
Figure BDA0002603866530000022
Figure BDA0002603866530000023
and
Figure BDA0002603866530000024
is a section (N)0,nmin) And (n)min,N1) Maximum absolute value of slope of inner interval, Kset1As a sensitivity coefficient, Numc1And Numc2Respectively, are sampling points n satisfying the following formulac1And nc2The number of (2):
Figure BDA0002603866530000025
Figure BDA0002603866530000026
b) except for nmin0Besides, the rest minimum value points nminSatisfies the following conditions:
Figure BDA0002603866530000027
wherein, Kset2Is a sensitivity coefficient;
13) in half period interval [ N1,N2]The judgment process of the step 12) is adopted, if the two half-period intervals meet the two criteria, the period is judged to have the arc high-resistance fault characteristic and is marked as a fault period;
14) and when the continuous number of the fault periods is larger than a set value, starting the fault positioning process.
Further, the absolute value of the interval slope is expressed as:
Figure BDA0002603866530000031
wherein the content of the first and second substances,
Figure BDA0002603866530000032
is at nsThe slope of the interval of points is such that,
Figure BDA0002603866530000033
to represent
Figure BDA0002603866530000034
The interval used is of length l and is nsIs a midpoint, n represents a point in the interval, i0And (n) is the zero sequence current at the point n.
Further, before the absolute value of the interval slope is calculated, the sampled zero sequence current is processed by adopting an improved robust local regression smoothing method based on the Graves criterion.
Further, the improved robust local regression smoothing method based on the grassbrix criterion specifically includes:
fitting the zero sequence current into a polynomial according to a set fitting error, introducing an iterative screening thought and an abnormal value screening principle of a Grubbs method, and performing weight coefficient w on the fitting erroriAnd the fitting coefficient alpha is iteratively updated.
Further, in step 2), in the interval [ N ]0+d,N1-d]Obtaining minimum value point nminWherein d is an oscillation elimination parameter.
Preferably, the sensitivity coefficient Kset1The value range of (A) is 0.80-0.85.
Preferably, the sensitivity coefficient Kset2The value range of (A) is 0.08-0.12.
Further, the fault locating process includes the following steps:
21) zero sequence current i for a certain measurement point0iIts positioning characteristic quantity in a certain half period interval:
Figure BDA0002603866530000035
wherein the content of the first and second substances,
Figure BDA0002603866530000036
Figure BDA0002603866530000038
to locate the feature quantity, cdirIs a coefficient;
22) based on adjacent positioning characteristic quantities
Figure BDA0002603866530000039
Determines the fault location.
Further, the coefficient cdirIs determined according to grounding modes of different neutral points and is determined by u0bThe interval slope curve is calculated to obtain:
Figure BDA0002603866530000037
wherein u is0bIs the zero sequence voltage at the bus.
Compared with the prior art, the invention has the following beneficial effects:
1. the method adopts the absolute value of the interval slope as the judgment basis of the arc high-resistance fault characteristics, can overcome the influence of noise on the description of the distortion characteristics, and improves the fault detection accuracy.
2. When the absolute value of the slope of the interval is calculated, the noise influence is further eliminated based on least square linear fitting and by combining the Grabbs rule and the robust local regression smoothing theory.
3. The invention further determines the fault section from the original fault detection and line selection of the arc high-resistance fault, realizes the accurate and rapid section positioning of the fault and provides information support for section selection tripping and fault recovery.
Drawings
FIG. 1 is a plot of absolute slope for a segment according to the present invention, wherein (1a) is under no fault and (1b) is under fault;
FIG. 2 is a schematic diagram showing the effectiveness of LLSF and Grubbs-RLRS in describing the characteristics of the interval slope curve, wherein (2a) is the zero sequence current waveform of the measured high-resistance fault, (2b) is the derivative curve, (2c) is the interval slope curve (non-absolute value), (2d) is the interval slope absolute value curve and the distortion detection;
FIG. 3 is a schematic flow chart of the present invention.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
As shown in fig. 3, this embodiment provides a method for positioning an arc high-resistance fault section of a power distribution network based on a section slope, where the method includes a fault detection process and a fault positioning process, in the fault detection process, a corresponding section slope absolute value is obtained according to an acquired zero-sequence current, whether each cycle of the zero-sequence current has an arc high-resistance fault feature is sequentially determined based on the section slope absolute value, a cycle having the arc high-resistance fault feature is recorded as a fault cycle, and when the number of consecutive fault cycles is greater than a set value, the fault positioning process is started; in the fault positioning process, fault section positioning is carried out based on the synchronous zero-sequence current and the zero-sequence voltage waveform of each measuring point.
First, interval slope curve
High resistance faults generally result from contact of the conductor with a high impedance grounded medium caused by an overhead line break or a tree break, which is generally unreliable, and air gaps are commonly present between the conductor and the grounded medium or within the grounded medium. Therefore, when a high-resistance ground fault occurs, the high-resistance ground fault is generally electrically connected with the ground through an arc forming network, so that nonlinear waveform distortion is generated in both fault current and zero-sequence current.
The waveform distortion of the zero sequence current can be described by a slope. However, calculating the slope directly by derivation or difference is clearly highly susceptible to signal noise, which may result from background noise, measurement errors, or invalid distortions due to arcing. To overcome the effect of this noise on the distortion characterization, the interval slope is calculated based on a least squares linear fit.
For a measured zero sequence current signal i0(n) at nsThe interval slope of the points is expressed as
Figure BDA0002603866530000051
And calculated based on least squares linear fit (1 initial least square fit), the absolute value of which
Figure BDA0002603866530000052
Expressed as:
Figure BDA0002603866530000053
wherein the content of the first and second substances,
Figure BDA0002603866530000054
is at nsThe slope of the interval of points is such that,
Figure BDA0002603866530000055
to represent
Figure BDA0002603866530000056
The interval used is of length l and is nsIs a midpoint, n represents a point in the interval, i0(n) is the zero sequence current at point n; let l be NT8 and NTRepresenting the number of samples in a power frequency cycle.
For the sine waveform of zero sequence current, the absolute value of interval slope
Figure BDA0002603866530000057
The minimum point is reached at the current maximum and minimum values, as in figure (1a), showing a "double Λ" shape at each cycle. For distorted waveforms, as shown in figure (1b),
Figure BDA0002603866530000058
and the minimum value point is reached near the maximum distortion point, so that the interval slope absolute value curve of the distorted waveform shows a double-M shape in a power frequency period. This feature can be used to distinguish most failure events from non-failure events.
However, due to the arc extinction phenomenon in the fault process and the serious measurement error caused by the high-resistance fault current amplitude being sometimes much smaller than the effective range, the zero-sequence current waveform is affected by short-time irregular distortion such as impulse noise, and the distortion is difficult to be effectively filtered by the traditional low-pass filter or wavelet filter. Therefore, preferably, before calculating the slope of the interval, an improved Robust Local Regression Smoothing (RLRS) method based on the Grubbs criterion is used for the interval
Figure BDA0002603866530000059
The sampled data in (1) is processed.
For point nsWill belong to the interval
Figure BDA00026038665300000510
Zero sequence current i in0(n) is represented by
Figure BDA00026038665300000511
Based on RLRS theory, m-order polynomial is established
Figure BDA00026038665300000512
To pair
Figure BDA00026038665300000513
The fit was performed with the fit error expressed as:
Figure BDA00026038665300000514
wherein, wiRepresents a weight coefficient, initially set to 1; based on RLRS, i.e. a set of α ═ α needs to be foundjI j ═ 0, 1,. m }, so that ξ is minimal. Let ξ' ═ 0, so that the calculated α can be expressed as:
α=(NTWN)-1NTWI (3)
wherein the content of the first and second substances,
Figure BDA0002603866530000061
and is
Figure BDA0002603866530000062
Figure BDA0002603866530000063
Is a diagonal matrix, Wi,i=wi
Figure BDA0002603866530000064
And is
Figure BDA0002603866530000065
Nonlinear distortion wave relative to fault zero-rest periodAnd the ineffective distortion with larger influence, such as impulse noise, has the characteristics of faster change and shorter duration. Introducing an iterative screening thought and an abnormal value screening principle of a Grubbs method to wiAnd alpha iterative update. The normalized residual for the Grubbs criterion is expressed as:
Figure BDA0002603866530000066
wherein ═ tonei|w i1 and i ═ 0, 1.., m };
Figure BDA0002603866530000067
expectation of representation, standard deviation of STD (). Updating wiThe following were used:
Figure BDA0002603866530000068
wherein G isp,NThe threshold value when the confidence coefficient is p is expressed, and p is generally 90-99.5%. In the present method, p is set to 90%; n denotes w in the current intervaliThe number of sampling points is 1. Gp,iTaking values at different p and N, we refer to the grabbs table. No w after the calculation of (2) to (5)iWhen the value is set from 1 to 0, use
Figure BDA0002603866530000069
Computing
Figure BDA00026038665300000610
Finally, the interval slope absolute value curve can be calculated point by point
Figure BDA00026038665300000611
And can also be calculated once every several points
Figure BDA00026038665300000612
And a curve is obtained by interpolation to reduce the amount of calculation. The effect of the overall LLSF-Grubbs-RLRS procedure can be illustrated by FIG. 2. As shown in FIG. 2aIf only a low pass filter is used, when the cut-off frequency f iscWhen the cut-off frequency is low, the influence of the impulse noise is rather enlarged, and thus the problem cannot be solved by using only a low-pass filter. Fig. 2b shows the derivative curve of the zero sequence current, and it can be seen by comparison that the interval slope curve calculated based on the linear least square has better noise fluctuation resistance, as shown in fig. 2 c. In addition, fig. 2c also demonstrates the role of the Grubbs-RLRS method in eliminating the impact of impulse noise, thereby enabling the interval slope absolute value curve to correctly exhibit the "double M" shaped characteristic.
Second, fault detection
On the basis of the interval slope calculation, the following process can be adopted for high-resistance fault detection:
the method comprises the following steps: as shown in fig. 2d, for each period of the zero sequence current, the maximum and minimum value points are calculated by FFT and are respectively positioned to the minimum value point N of the absolute value of the slope of the interval nearby the maximum and minimum value points1And N2。N0Is N of the previous cycle2And (4) point.
Step two: for half period interval [ N0,N1],nminIs the interval [ N0+d,N1-d]2d is to avoid the absolute value calculation
Figure BDA00026038665300000613
May be present in the vicinity of the zero crossing. The half-cycle interval [ N ] can be called if and only if the following two criteria are met0,N1]The nonlinear characteristic of high-resistance fault is as follows:
1) demarcating the first nminIs nmin0It should satisfy:
Figure BDA0002603866530000071
wherein the content of the first and second substances,
Figure BDA0002603866530000072
and is
Figure BDA0002603866530000073
And
Figure BDA0002603866530000074
is a section (N)0,nmin) And (n)min,N1) Inner maximum (see fig (2 d)); kset1The sensitivity coefficient is set to be 0.80-0.85 so as to ensure the sensitivity and the safety of detection at the same time. Numc1And Numc2Are respectively the sampling points n satisfying the formulas (7) and (8)c1And nc2The number of (2).
Figure BDA0002603866530000075
Figure BDA0002603866530000076
2) Considering the Grubbs-RLRS filter residue in case of very strong noise, [ N [ ]0+d,N1-d]There may be more than one nmin. At this time, except nmin0And the rest nminIt should satisfy:
Figure BDA0002603866530000077
wherein, Kset2The sensitivity coefficient is also set to 0.10.
Step three: in half period interval [ N1,N2]In the period of half period [ N ]0,N1]The same judgment process is carried out. If the two half-period intervals are judged to have the nonlinear characteristic of high-resistance fault, the period is marked as a fault period.
Step four: and (4) judging the steps from one step to three step by period, if a plurality of continuous periods are marked as 'fault periods', judging that the high-resistance fault occurs, and starting a fault positioning process.
Third, fault location
Based on measurements after high impedance fault is detectedThe synchronous zero-sequence current and zero-sequence voltage waveforms of the point, if there is no zero-sequence voltage, the zero-sequence voltage u at the bus is used0bAnd as a reference voltage, performing a fault section positioning process. Zero sequence current i for a certain measurement point0iThe positioning characteristic quantity of the positioning device in a certain half-period interval is represented as follows:
Figure BDA0002603866530000078
wherein the content of the first and second substances,
Figure BDA0002603866530000079
cdiris a coefficient of u0bThe interval slope curve is calculated to obtain:
Figure BDA00026038665300000710
wherein, cdirFurther by dividing by
Figure BDA00026038665300000711
Or
Figure BDA00026038665300000712
Is normalized, and d represents the differential. In addition, when a cycle is not designated as a "fault cycle", it is two "half cycles" of
Figure BDA0002603866530000081
Are all 0.
Based on the characteristic quantity, for three neutral point grounding modes, before fault point
Figure BDA0002603866530000082
Far greater than 0, after the fault point
Figure BDA0002603866530000083
Equal to or less than 0. When the transition resistance is extremely large and the zero-sequence current is extremely small, the ratio and the influence of the active component will change, and at the moment, the fault pointAfter that
Figure BDA0002603866530000084
Will be slightly larger than 0 but in most cases still much smaller than before the fault point
Figure BDA0002603866530000085
The characteristic quantity of the positioning of the adjacent half period can be passed
Figure BDA0002603866530000086
Determines the fault location.
It should be noted that, in a resonant grounded system, when the fault current is extremely small, the zero sequence current of each measurement point is affected by the active component in the system and the phase relationship changes. In this case, it is preferable that the air conditioner,
Figure BDA0002603866530000087
Figure BDA0002603866530000088
more suitably, therefore, for a resonant grounded system, two types of c are required for segment positioningdirAnd (6) judging.
The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (10)

1. A power distribution network arc high resistance fault section positioning method based on interval slope is characterized by comprising a fault detection process and a fault positioning process,
in the fault detection process, acquiring a corresponding interval slope absolute value according to the acquired zero sequence current, sequentially judging whether each period of the zero sequence current has arc high-resistance fault characteristics or not based on the interval slope absolute value, recording the periods with the arc high-resistance fault characteristics as fault periods, and starting the fault positioning process when the continuous number of the fault periods is greater than a set value;
in the fault positioning process, fault section positioning is carried out based on the synchronous zero-sequence current and the zero-sequence voltage waveform of each measuring point.
2. The method for positioning the arc high-resistance fault section of the power distribution network based on the interval slope as claimed in claim 1, wherein the fault detection process comprises the following steps:
11) acquiring zero sequence current, obtaining the maximum and minimum values of the current for each period of the zero sequence current, and positioning to the minimum value point N of the interval slope absolute value corresponding to the period based on the maximum and minimum values of the current1And N2And will be the point N of the previous cycle2As N0Composition interval [ N0,N2];
12) For half period interval [ N0,N1]Obtaining the minimum value point nminJudging whether the minimum value point simultaneously meets the following two criteria, if so, executing the step 13), otherwise, returning to the step 11) to judge the next period:
a) demarcating the first nminIs nmin0Which satisfies:
Figure FDA0002603866520000011
wherein the content of the first and second substances,
Figure FDA0002603866520000012
Figure FDA0002603866520000013
and
Figure FDA0002603866520000014
is a section (N)0,nmin) And (n)min,N1) Interval of innerMaximum absolute value of slope, Kset1As a sensitivity coefficient, Numc1And Numc2Respectively, are sampling points n satisfying the following formulac1And nc2The number of (2):
Figure FDA0002603866520000015
Figure FDA0002603866520000016
b) except for nmin0Besides, the rest minimum value points nminSatisfies the following conditions:
Figure FDA0002603866520000021
wherein, Kset2Is a sensitivity coefficient;
13) in half period interval [ N1,N2]The judgment process of the step 12) is adopted, if the two half-period intervals meet the two criteria, the period is judged to have the arc high-resistance fault characteristic and is marked as a fault period;
14) and when the continuous number of the fault periods is larger than a set value, starting the fault positioning process.
3. The method for positioning the arc high-resistance fault section of the power distribution network based on the interval slope as claimed in claim 2, wherein the absolute value of the interval slope is represented as:
Figure FDA0002603866520000022
wherein the content of the first and second substances,
Figure FDA0002603866520000023
is at nsThe slope of the interval of points is such that,
Figure FDA0002603866520000024
to represent
Figure FDA0002603866520000025
The interval used is of length l and is nsIs a midpoint, n represents a point in the interval, i0And (n) is the zero sequence current at the point n.
4. The method for positioning the arc high-resistance fault section of the power distribution network based on the interval slope as claimed in claim 2, wherein the sampled zero-sequence current is processed by using an improved robust local regression smoothing method based on the Graves criterion before calculating the absolute value of the interval slope.
5. The arc high-resistance fault section positioning method for the power distribution network based on the interval slope as claimed in claim 4, wherein the improved robust local regression smoothing method based on the Grabbs criterion is specifically as follows:
fitting the zero sequence current into a polynomial according to a set fitting error, introducing an iterative screening thought and an abnormal value screening principle of a Grubbs method, and performing weight coefficient w on the fitting erroriAnd the fitting coefficient alpha is iteratively updated.
6. The method for positioning arc high-resistance fault sections of power distribution networks based on interval slopes as claimed in claim 2, wherein in the step 2), in the interval [ N ]0+d,N1-d]Obtaining minimum value point nminWherein d is an oscillation elimination parameter.
7. The method for positioning arc high-resistance fault section of power distribution network based on interval slope as claimed in claim 2, wherein the sensitivity coefficient K isset1The value range of (A) is 0.80-0.85.
8. The method for positioning arc high-resistance fault section of power distribution network based on interval slope as claimed in claim 2, wherein the sensitivity coefficient K isset2Is in the range of 0.08 to0.12。
9. The arc high resistance fault section positioning method for the power distribution network based on the interval slope as claimed in claim 1, wherein the fault positioning process comprises the following steps:
21) zero sequence current i for a certain measurement point0iIts positioning characteristic quantity in a certain half period interval:
Figure FDA0002603866520000031
wherein the content of the first and second substances,
Figure FDA0002603866520000032
Figure FDA0002603866520000033
to locate the feature quantity, cdirIs a coefficient;
22) based on adjacent positioning characteristic quantities
Figure FDA0002603866520000034
Determines the fault location.
10. The method for positioning arc high-resistance fault sections of power distribution networks based on interval slope as claimed in claim 9, wherein the coefficient c isdirIs determined according to grounding modes of different neutral points and is determined by u0bThe interval slope curve is calculated to obtain:
Figure FDA0002603866520000035
wherein u is0bIs the zero sequence voltage at the bus.
CN202010732977.8A 2020-07-27 2020-07-27 Power distribution network arc high-resistance fault section positioning method based on interval slope Pending CN111896842A (en)

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CN202010732977.8A CN111896842A (en) 2020-07-27 2020-07-27 Power distribution network arc high-resistance fault section positioning method based on interval slope
AU2020327344A AU2020327344B2 (en) 2020-07-27 2020-12-11 Method for locating arcing high-impedance fault section in power distribution network based on interval slope
PCT/CN2020/135704 WO2022021740A1 (en) 2020-07-27 2020-12-11 Interval slope-based arcing high impedance fault section positioning method for power distribution network

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