CN114137361A - Power distribution network single-phase earth fault line selection method - Google Patents

Power distribution network single-phase earth fault line selection method Download PDF

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Publication number
CN114137361A
CN114137361A CN202111426019.9A CN202111426019A CN114137361A CN 114137361 A CN114137361 A CN 114137361A CN 202111426019 A CN202111426019 A CN 202111426019A CN 114137361 A CN114137361 A CN 114137361A
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zero sequence
phase
fault
bus
line
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张志华
刘健
师琛
张英
王毅钊
邵文权
刘浩
吴子豪
王辰曦
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National Network Xi'an Environmental Protection Technology Center Co ltd
Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd
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Electric Power Research Institute of State Grid Shanxi Electric Power Co Ltd
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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
    • 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
    • G01R31/50Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/52Testing for short-circuits, leakage current or ground faults

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Abstract

The invention discloses a single-phase earth fault line selection method for a power distribution network, which comprises the following steps: selecting a fault phase; acquiring and obtaining bus zero-sequence voltage and all line zero-sequence currents at each preset stage; calculating the zero sequence voltage change rate and the zero sequence current change rate of each adjacent disturbance stage in the fault phase grounding working process and the disturbance increment correlation of the zero sequence voltage and the zero sequence current based on the acquired bus zero sequence voltage and all line zero sequence currents; when the criterion is established, the line is a fault line, otherwise, the line is a sound line. The method provided by the invention can realize reliable judgment of the single-phase earth fault line of the resonant power distribution network.

Description

Power distribution network single-phase earth fault line selection method
Technical Field
The invention belongs to the technical field of single-phase earth fault processing of a power distribution network, and particularly relates to a single-phase earth fault line selection method of the power distribution network.
Background
The medium-voltage distribution network adopts a small-current grounding mode and the connection of the arc suppression coil can reduce the single-phase grounding fault current level, so that the single-phase grounding line selection is difficult, and serious accidents caused by the continuous existence of grounding arcs are frequent.
At present, many research results are obtained in the aspect of fault line selection of the power distribution network, such as: in a steady state quantity method, a transient state quantity method, an injection method and the like, because the arc suppression coil can only compensate power frequency capacitive current, in order to reliably extinguish the arc, the methods all need to adopt tripping measures, and have adverse effects on the power supply reliability. In summary, a new method for selecting a single-phase earth fault of a power distribution network is needed.
Disclosure of Invention
The invention aims to provide a single-phase earth fault line selection method for a power distribution network, so as to solve one or more technical problems. The method provided by the invention can realize reliable judgment of the single-phase earth fault line of the resonant power distribution network.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a single-phase earth fault line selection method for a power distribution network, which comprises the following steps:
step 1, monitoring neutral point voltage of grounding transformer and three-phase voltage value of bus
Figure BDA0003378462990000011
When the bus zero sequence voltage amplitude U(0)Greater than protection setting value U0setThen, the zero sequence voltage of the bus is acquired
Figure BDA0003378462990000012
All linesZero sequence current of road
Figure BDA0003378462990000013
Selecting a fault phase; wherein, i is 1,2, …, k, i is the line number, total k lines;
step 2, switching on the action of the grounding switch of the fault phase bus, and acquiring and obtaining the zero sequence voltage of the bus
Figure BDA0003378462990000014
Zero sequence current of all lines
Figure BDA0003378462990000015
Switching on the resistance switch in the neutral point of the power distribution network, and switching on the resistance R in the neutral point of the power distribution networkgAcquiring and obtaining bus zero sequence voltage
Figure BDA0003378462990000016
Zero sequence current of all lines
Figure BDA0003378462990000017
The action of the fault phase bus grounding switch is switched off, and bus zero sequence voltage is acquired
Figure BDA0003378462990000018
Zero sequence current of all lines
Figure BDA0003378462990000019
Neutral point middle resistance RgThe circuit switch acts to open the gate, and the zero sequence voltage of the bus is acquired and obtained
Figure BDA0003378462990000021
Zero sequence current of all lines
Figure BDA0003378462990000022
Step 3, calculating the zero sequence voltage change rate K of each adjacent disturbance stage in the fault phase grounding working process based on the bus zero sequence voltage and all the line zero sequence currents obtained in the step 2U,nZero sequence current change rate KIi,nAnd zero sequence voltage, zero sequence current disturbance increment correlation ρUI_i,n(ii) a When criterion is rhoUI_i,3<Krel_1*0.30||ρUI_i,4>Krel_2When the line i is a fault line when the line i is established, or else, the line i is a sound line; wherein the content of the first and second substances,
Figure BDA0003378462990000023
Figure BDA0003378462990000024
n is the perturbation phase, Krel_1、Krel_2Is a reliability factor.
A further improvement of the method of the present invention is that, in step 1, the step of selecting the faulty phase specifically includes:
according to phase voltage amplitude UA、UB、UCAnd (4) selecting the fault phase by using a related fault phase selection principle.
A further development of the process according to the invention consists in that, in step 1, U0set=KUNWherein, UNAnd K is a selected coefficient.
The method of the invention is further improved in that the value of K is 15%.
The method of the invention is further improved in that n takes on values of 1,2, 3 and 4.
The process of the invention is further improved in that Krel_1Taking 1.10-1.3.
The process of the invention is further improved in that Krel_2Taking 0.80-0.90.
Compared with the prior art, the invention has the following beneficial effects:
in the method provided by the invention, the reliable judgment of the single-phase earth fault line of the resonant power distribution network can be realized by utilizing the fault phase-to-earth multi-disturbance feature fused resonant earth power distribution network fault line selection method; and (1) the redundancy of fault line selection is improved by multiple disturbances, the transition resistance is improved, and the comprehensive utilization of multiple disturbances in the fault phase grounding and disconnection processes is realized. (2) The fault information characteristics are enhanced by using the mutual matching switching of the resistors in the grounding and neutral points of the fault phase bus to implement multiple times of disturbance, the incremental change characteristics of zero sequence voltage and current of a fault line are obviously different from those of any sound line, and the accuracy of fault line selection is greatly improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic flow chart of a single-phase earth fault line selection method for a power distribution network according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a line selection system according to an embodiment of the present invention;
FIG. 3 is a timing diagram illustrating ground disturbance fault detection according to an embodiment of the present invention;
fig. 4 is a schematic flow chart of a fault line selection method for a resonant grounded power distribution network by using a fault-phase-to-ground multi-disturbance feature according to an embodiment of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The invention is described in further detail below with reference to the accompanying drawings:
example 1
Referring to fig. 1, a method for selecting a single-phase ground fault of a power distribution network according to an embodiment of the present invention includes the following steps:
step 1, monitoring neutral point voltage of grounding transformer and three-phase voltage value of bus
Figure BDA0003378462990000041
When the bus zero sequence voltage amplitude U(0)Greater than protection setting value U0setThen, the zero sequence voltage of the bus is acquired
Figure BDA0003378462990000042
Zero sequence current of all lines
Figure BDA0003378462990000043
Selecting a fault phase; wherein, i is 1,2, …, k, i is the line number, total k lines;
step 2, switching on the action of the grounding switch of the fault phase bus, and acquiring and obtaining the zero sequence voltage of the bus
Figure BDA0003378462990000044
Zero sequence current of all lines
Figure BDA0003378462990000045
Switching on the resistance switch in the neutral point of the power distribution network, and switching on the resistance R in the neutral point of the power distribution networkgAcquiring and obtaining bus zero sequence voltage
Figure BDA0003378462990000046
Zero sequence current of all lines
Figure BDA0003378462990000047
The action of the fault phase bus grounding switch is switched off, and bus zero sequence voltage is acquired
Figure BDA0003378462990000048
Zero sequence current of all lines
Figure BDA0003378462990000049
Neutral point middle resistance RgThe circuit switch acts to open the gate, and the zero sequence voltage of the bus is acquired and obtained
Figure BDA00033784629900000410
Zero sequence current of all lines
Figure BDA00033784629900000411
Step 3, calculating the zero sequence voltage change rate K of each adjacent disturbance stage in the fault phase grounding working process based on the bus zero sequence voltage and all the line zero sequence currents obtained in the step 2U,nZero sequence current change rate KIi,nAnd zero sequence voltage, zero sequence current disturbance increment correlation ρUI_i,n(ii) a When criterion is rhoUI_i,3<Krel_1*0.30||ρUI_i,4>Krel_2When the line i is a fault line when the line i is established, or else, the line i is a sound line; wherein the content of the first and second substances,
Figure BDA00033784629900000412
Figure BDA00033784629900000413
n is the perturbation phase, Krel_1、Krel_2Is a reliability factor.
The method disclosed by the embodiment of the invention is a resonant grounded power distribution network fault line selection method by utilizing fault phase grounding multi-disturbance feature fusion, and can realize reliable judgment of a single-phase grounded fault line of a resonant power distribution network. Compared with the prior art, the method has the advantages that at least: (1) the multiple disturbance improves the redundancy of fault line selection, improves the transition resistance, and realizes the comprehensive utilization of the multiple disturbance in the fault phase grounding and disconnecting processes. (2) The fault information characteristics are enhanced by using the mutual matching switching of the resistors in the grounding and neutral points of the fault phase bus to implement multiple times of disturbance, the incremental change characteristics of zero sequence voltage and current of a fault line are obviously different from those of any sound line, and the accuracy of fault line selection is greatly improved.
Example 2
The single-phase earth fault line selection method for the power distribution network comprises the following steps:
(1) real-time monitoring neutral point voltage of grounding transformer and three-phase voltage value of bus
Figure BDA0003378462990000051
When the bus zero sequence voltage amplitude U(0)Less than protection setting value U0setReturning to the calculation; when the bus zero sequence voltage amplitude U(0)Greater than protection setting value U0setAnd when the single-phase ground fault occurs, the line selection device is started.
(2) Collecting bus zero sequence voltage
Figure BDA0003378462990000052
Zero sequence current of all lines
Figure BDA0003378462990000053
i is the line number, and k lines are total. According to phase voltage amplitude UA、UB、UCThe fault phase is selected by utilizing the related fault phase selection principle, and the fault phase bus grounding switch K1And (5) closing the switch.
(3) Grounding switch K for fault phase bus1After closing, the zero sequence voltage of the bus is collected for the second time
Figure BDA0003378462990000054
Zero sequence current of all lines
Figure BDA0003378462990000055
i is the line number, and k lines are total.
(4) Switching resistance K in neutral point of power distribution network2The action is switched on, and a middle resistor R is put into a neutral point of the power distribution networkg. Neutral point input medium resistance RgThen, the zero sequence voltage of the bus is collected for the third time
Figure BDA0003378462990000056
Zero sequence current of all lines
Figure BDA0003378462990000057
i is the line number, and k lines are total.
(5) Grounding switch K for fault phase bus1And (5) opening the brake. Grounding switch K for fault phase bus1After action brake opening, the zero sequence voltage of the bus is collected for the fourth time
Figure BDA0003378462990000058
Zero sequence current of all lines
Figure BDA0003378462990000059
i is the line number, and k lines are total.
(6) Neutral point middle resistance RgLoop switch K2And (5) opening the brake. Exiting neutral resistance RgAnd then, collecting the zero sequence voltage of the bus for the fifth time
Figure BDA00033784629900000510
Zero sequence current of all lines
Figure BDA00033784629900000511
i is the line number, and k lines are total.
(7) Calculating the zero sequence voltage change rate K of each adjacent disturbance stage in the fault phase grounding working processU,nZero sequence current change rate KIi,nAnd simultaneously calculating the disturbance increment correlation rho of zero sequence voltage and zero sequence currentUI_i,nAnd judging whether the criterion is satisfied, when the criterion rho is satisfiedUI_i,3<Krel_1*0.30||ρUI_i,4>Krel_2When x 3.60 is established, the line i is a faulty line, otherwise it is a healthy line. Finishing line selection; wherein the content of the first and second substances,
Figure BDA00033784629900000512
Figure BDA00033784629900000513
n is a disturbance stage; u shape0set=KUNWherein U isNThe rated voltage of the bus is adopted, and the general value of K is 15 percent; n is 1,2, 3 or 4; krel_1、Krel_2For a reliability factor, Krel_1Taking 1.10-1.3, Krel_2Taking 0.80-0.90.
The embodiment of the invention provides a fault line selection method for a resonance grounding power distribution network by utilizing fault phase grounding multiple disturbance feature fusion, which fully utilizes increment change features of zero sequence voltage and current of a fault line in a multiple disturbance process of power distribution network fault phase grounding, constructs fault line selection criterion by utilizing multiple disturbance increment change features fusion, can realize reliable judgment of a single-phase grounding fault line of the resonance power distribution network, and further improves the adaptability of fault line selection transition resistance of the resonance grounding power distribution network.
The principle analysis of the technical scheme of the embodiment of the invention comprises the following steps: the fault phase grounding type (also called as active transfer type) arc extinguishing system opens up a new way for timely and reliably extinguishing single-phase grounding electric arc, can extinguish the electric arc without tripping, can not influence continuous power supply during transient grounding, and is already applied to domestic and foreign electric power systems. The fault phase grounding type arc quenching system can generate larger disturbance to the single-phase grounding characteristic of the system in the working process, and can provide more obvious electrical quantity characteristic for single-phase grounding fault line selection. Based on the analysis, the method provided by the embodiment of the invention integrates the relative change characteristics of the multiple-disturbance zero-sequence voltage and the multiple-disturbance zero-sequence current on the basis of the increment change characteristics of the zero-sequence voltage and the zero-sequence current in the multiple-disturbance process after single-phase grounding, constructs the fault line selection scheme with the multiple-disturbance characteristic integration, and further improves the adaptability of the fault line selection transition resistance of the resonant grounded power distribution network. Specifically, the embodiment of the invention provides a fault line selection method for a resonant grounded power distribution network by utilizing fusion of fault phase grounding multiple disturbance characteristics, which mainly aims at the problem of processing single-phase ground faults of the resonant power distribution network, multiple disturbances are implemented by mutually matching and switching resistors in a fault phase bus grounding and a neutral point, fault line selection is realized by utilizing change characteristics of zero sequence voltage and zero sequence current, and in the multiple disturbance process of power distribution network fault phase grounding, the incremental change characteristics of zero sequence voltage and current of a fault line are obviously different from those of any sound line.
Example 3
Referring to fig. 2 to 4, a resonant grounded power distribution network using the active fault grounding device shown in fig. 2; performing a ground disturbance cooperative action according to the timing sequence shown in fig. 3; as shown in fig. 4, an embodiment of the present invention provides a fault line selection method for a resonant grounded power distribution network by using fault phase grounding multiple disturbance feature fusion, including the following steps:
(1) real-time monitoring neutral point voltage of grounding transformer and three-phase voltage value of bus
Figure BDA0003378462990000061
When the bus zero sequence voltage amplitude U(0)Less than protection setting value U0setThen return to the calculation (U)0set=KUNWherein U isNIs the rated voltage of the bus, and K generally takes a value of 15%); when the bus zero sequence voltage amplitude U(0)Greater than protection setting value U0setAnd when the single-phase ground fault occurs, the line selection device is started.
(2) Collecting bus zero sequence voltage
Figure BDA0003378462990000071
Zero sequence current of all lines
Figure BDA0003378462990000072
Wherein i is a line number, and k lines are total. According to phase voltage amplitude UA、UB、UCThe fault phase is selected by utilizing the related fault phase selection principle, and the fault phase bus grounding switch K1And (5) closing the switch.
(3) Grounding switch K for fault phase bus1After closing, the zero sequence voltage of the bus is collected for the second time
Figure BDA0003378462990000073
Zero sequence current of all lines
Figure BDA0003378462990000074
Wherein i is a line number, and k lines are total.
(4) Switching resistance K in neutral point of power distribution network2The action is switched on, and a middle resistor R is put into a neutral point of the power distribution networkg. Neutral point input medium resistance RgThen, the zero sequence voltage of the bus is collected for the third time
Figure BDA0003378462990000075
Zero sequence current of all lines
Figure BDA0003378462990000076
Wherein i is a line number, and k lines are total.
(5) Grounding switch K for fault phase bus1And (5) opening the brake. Grounding switch K for fault phase bus1After action brake opening, the zero sequence voltage of the bus is collected for the fourth time
Figure BDA0003378462990000077
Zero sequence current of all lines
Figure BDA0003378462990000078
Wherein i is a line number, and k lines are total.
(6) Neutral point middle resistance RgLoop switch K2And (5) opening the brake. Exiting neutral resistance RgAnd then, collecting the zero sequence voltage of the bus for the fifth time
Figure BDA0003378462990000079
Zero sequence current of all lines
Figure BDA00033784629900000710
Wherein i is a line number, and k lines are total.
(7) Calculating the zero sequence voltage change rate K of each adjacent disturbance stage in the fault phase grounding working processU,n
Figure BDA00033784629900000711
Figure BDA00033784629900000712
Rate of change of zero sequence current KIi,n
Figure BDA00033784629900000713
Wherein n is 1,2, …, 4. Simultaneously calculating the disturbance increment correlation rho of zero sequence voltage and zero sequence currentUI_i,n
Figure BDA00033784629900000714
Figure BDA00033784629900000715
And judging whether the criterion is satisfied, when the criterion rho is satisfiedUI_i,3<Krel_1*0.30、ρUI_i,4>Krel_2*3.60(Krel_1、Krel_2For a reliability factor, Krel_1Taking 1.10-1.3, Krel_2Taking any one of 0.80-0.90) as a right line, the line i is a fault line, otherwise, the line is a sound line.
According to the fault line selection method for the resonant grounded power distribution network with the fused fault phase grounding multi-disturbance characteristics, provided by the embodiment of the invention, multi-disturbance is implemented by mutually matching switching of the grounding of the fault phase bus and the resistance in the neutral point, the fault line selection is realized by utilizing the change characteristics of the zero-sequence voltage and the zero-sequence current, the fault information characteristics are enhanced by utilizing the input of the resistance in the neutral point, the zero-sequence current amplitude of the fault line is obviously increased after the bus grounding switch is opened, and is obviously different from a healthy line, so that the accuracy of the fault line selection is greatly improved. And secondly, the redundancy of fault line selection is improved through multiple disturbances, the transition resistance is improved, and the comprehensive utilization of multiple disturbances in the fault phase grounding and disconnecting processes is realized.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (7)

1. A single-phase earth fault line selection method for a power distribution network is characterized by comprising the following steps:
step 1, monitoring neutral point voltage of grounding transformer and three-phase voltage value of bus
Figure FDA0003378462980000011
When the bus zero sequence voltage amplitude U(0)Greater than protection setting value U0setThen, the zero sequence voltage of the bus is acquired
Figure FDA0003378462980000012
Zero sequence current of all lines
Figure FDA0003378462980000013
Selecting a fault phase; wherein, i is 1,2, …, k, i is the line number, total k lines;
step 2, switching on the action of the grounding switch of the fault phase bus, and acquiring and obtaining the zero sequence voltage of the bus
Figure FDA0003378462980000014
Zero sequence current of all lines
Figure FDA0003378462980000015
Switching a resistance in a neutral point of a distribution networkActing closing, and putting neutral resistor R into neutral point of distribution networkgAcquiring and obtaining bus zero sequence voltage
Figure FDA0003378462980000016
Zero sequence current of all lines
Figure FDA0003378462980000017
The action of the fault phase bus grounding switch is switched off, and bus zero sequence voltage is acquired
Figure FDA0003378462980000018
Zero sequence current of all lines
Figure FDA0003378462980000019
Neutral point middle resistance RgThe circuit switch acts to open the gate, and the zero sequence voltage of the bus is acquired and obtained
Figure FDA00033784629800000110
Zero sequence current of all lines
Figure FDA00033784629800000111
Step 3, calculating the zero sequence voltage change rate K of each adjacent disturbance stage in the fault phase grounding working process based on the bus zero sequence voltage and all the line zero sequence currents obtained in the step 2U,nZero sequence current change rate KIi,nAnd zero sequence voltage, zero sequence current disturbance increment correlation ρUI_i,n(ii) a When criterion is rhoUI_i,3<Krel_1*0.30||ρUI_i,4>Krel_2When the line i is a fault line when the line i is established, or else, the line i is a sound line; wherein the content of the first and second substances,
Figure FDA00033784629800000112
n is the perturbation phase, Krel_1、Krel_2Is a reliability factor.
2. The method according to claim 1, wherein in step 1, the step of selecting the faulty phase specifically comprises:
according to phase voltage amplitude UA、UB、UCAnd (4) selecting the fault phase by using a related fault phase selection principle.
3. The single-phase earth fault line selection method for the power distribution network according to claim 1, wherein in step 1,
U0set=KUN
wherein, UNAnd K is a selected coefficient.
4. The single-phase earth fault line selection method for the power distribution network according to claim 3, wherein the value of K is 15%.
5. The single-phase earth fault line selection method for the power distribution network according to claim 1, wherein the value of n is 1,2, 3 and 4.
6. The single-phase earth fault line selection method for the power distribution network according to claim 1, wherein K isrel_1Taking 1.10-1.3.
7. The single-phase earth fault line selection method for the power distribution network according to claim 1, wherein K isrel_2Taking 0.80-0.90.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115343658A (en) * 2022-10-19 2022-11-15 广东电网有限责任公司佛山供电局 Grounding state identification method and device based on resistance type strain sensor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115343658A (en) * 2022-10-19 2022-11-15 广东电网有限责任公司佛山供电局 Grounding state identification method and device based on resistance type strain sensor
CN115343658B (en) * 2022-10-19 2023-01-24 广东电网有限责任公司佛山供电局 Grounding state identification method and device based on resistance type strain sensor

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