CN110703040A - Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference - Google Patents

Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference Download PDF

Info

Publication number
CN110703040A
CN110703040A CN201911010569.5A CN201911010569A CN110703040A CN 110703040 A CN110703040 A CN 110703040A CN 201911010569 A CN201911010569 A CN 201911010569A CN 110703040 A CN110703040 A CN 110703040A
Authority
CN
China
Prior art keywords
fault
phase
difference
phase current
distribution network
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201911010569.5A
Other languages
Chinese (zh)
Inventor
鲁苏延
丁孝华
张蓓蓓
鲁文
时金媛
苏标龙
徐希
张可新
钱玉麟
安新成
袁伟
曹连连
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nari Technology Co Ltd
NARI Nanjing Control System Co Ltd
Original Assignee
Nari Technology Co Ltd
NARI Nanjing Control System Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nari Technology Co Ltd, NARI Nanjing Control System Co Ltd filed Critical Nari Technology Co Ltd
Priority to CN201911010569.5A priority Critical patent/CN110703040A/en
Publication of CN110703040A publication Critical patent/CN110703040A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • 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 discloses a distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference, when a single-phase earth fault occurs in a distribution network, three-phase current data information of each section is acquired from a related current data acquisition device, and the three-phase current mutation of each section is calculated according to the information; then, processing the waveform of the phase current abrupt change quantity of each section by using the proposed waveform difference calculation method to obtain the difference characteristic quantity of each section; and finally, distinguishing upstream and downstream faults and sound sections according to the difference characteristic quantity, and determining a specific fault line according to the power grid topology model. The method is not influenced by a system grounding mode and fault conditions, is not limited by a specific time period and a frequency band after the fault occurs, and has high positioning sensitivity and reliability.

Description

Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference
Technical Field
The invention relates to the field of power system relay protection, in particular to a distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference.
Background
A small-current grounding system is widely adopted in a 10kV medium-voltage distribution network in China, namely two grounding modes of a neutral point grounding without grounding or grounding through an arc suppression coil are adopted. Single-phase earth faults are the most common faults in low-current earthed power distribution networks, exceeding 80% of the total number of faults occurring thereon. After the power distribution system has single-phase earth faults, the three-phase line voltages still keep a symmetrical relation, continuous power supply to loads is not influenced, and therefore the power distribution system still allows the power distribution system to operate with faults for 1-2 hours so as to improve the reliability of power supply. However, if the fault is not eliminated for a long time, a series of more serious consequences such as burning of the electrical equipment can be caused.
Therefore, after a single-phase earth fault occurs in the low-current earth system, a fault point needs to be quickly found and cut off under the condition of ensuring uninterrupted power supply, so as to ensure safe and reliable operation of the power distribution network. However, in China, the distribution network line structure is complex, the neutral point grounding modes are not uniform, the distribution network single-phase grounding fault types are various, the fault rules are usually changeable and difficult to accurately grasp, and meanwhile, the single-phase grounding fault in the low-current grounding system also has the problems of weak steady-state electrical quantity, short transient process and the like which directly influence fault positioning, and the accurate positioning of the distribution network single-phase grounding fault is still very difficult.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems, the invention provides a distribution network single-phase earth fault positioning method based on the difference of the current mutation of the fault phase and the non-fault phase, which can be used for quickly and reliably positioning faults.
The technical scheme is as follows: in order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows: a distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference comprises the following steps:
(1) judging that a single-phase earth fault occurs in the power distribution network, and acquiring three-phase current data of each section from a related current data acquisition device;
(2) calculating the three-phase current abrupt change quantity of each section;
(3) calculating the waveform difference of the phase current mutation quantity between every two phases of each section, and selecting the maximum value from the three results as the characteristic quantity of the phase current mutation quantity difference of the fault phase and the non-fault phase of the section;
(4) comparing the phase current mutation quantity difference characteristic quantities of all sections, judging the section with larger difference characteristic quantity as a fault upstream section, and judging the section with smaller difference characteristic quantity as a sound and fault downstream section;
(5) and (4) determining a specific fault section by combining the power distribution network topological structure according to the judgment result in the step 4.
Further, in step 1, the acquired three-phase current data information of each segment at least includes phase current data of a non-fault normal operation state in two cycles before the fault occurs to phase current data of a fault operation state in three cycles after the fault occurs.
Further, in step 2, a three-phase current sudden change calculation formula after each section fails is shown:
wherein, Δ inRepresents the phase current abrupt change, t, corresponding to the nth sampling point in the period after the fault0At the approximate time of failure, T is the power frequency period, NsIs the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
Further, in step 3, the waveform difference calculation method includes:
wherein d isA-BRepresenting the waveform difference between waveform A and waveform B, iA(n)、iB(N) correspond to the sample values, N, of the waveform A, B at the nth sample point, respectivelysIs the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
Further, in the step 4, the method for defining the size of the difference feature quantity includes: and judging the section with the difference characteristic quantity greater than 70% of the maximum difference characteristic quantity as a fault upstream section, and judging the section with the difference characteristic quantity less than or equal to 70% of the maximum difference characteristic quantity as a sound and fault downstream section.
Further, in step 5, fault location is performed according to the following logic: if the parts previously determined as the upstream sections are all adjacent sections, the part determined as the upstream section, which is positioned at the rearmost end (farthest from the bus) of the topology, is a faulty section; if the sections are determined to be partially distributed or the majority of the sections in the system are determined to be upstream sections, the bus fault is determined to occur.
Has the advantages that: compared with the prior art, the distribution network single-phase earth fault positioning method based on the fault phase non-fault phase current mutation difference has the following remarkable advantages: the analysis and judgment are carried out only through the three-phase current data, and the method can be easily realized under the prior art condition; the fault characteristics of the phase current sudden change quantity are used in the temporary steady-state stage after the single-phase earth fault occurs, the accurate judgment of the fault moment is not relied on, and the influence of a system grounding mode and the single-phase earth fault condition is avoided; the proposed waveform difference calculation method can well distinguish an upstream section from a downstream or healthy section of the single-phase earth fault by combining the waveform of the phase current break variable of the fault non-fault phase of a specific section, and has high positioning reliability.
Drawings
FIG. 1 is a schematic diagram of system current distribution after a single-phase earth fault of a distribution network;
FIG. 2 is a vector diagram of phase voltage step quantities;
fig. 3 is a flow chart of the distribution network single-phase earth fault location of the present invention;
FIG. 4 is a schematic diagram of a PSCAD simulation verification system;
FIG. 5 is a waveform diagram of three-phase current break variables of a fault line in a simulation example;
fig. 6 is a waveform diagram of three-phase current break variables of a non-fault line in a simulation example.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
The invention discloses a distribution network single-phase earth fault positioning method based on phase current mutation difference of fault phases and non-fault phases, and aims to solve the problem of single-phase earth fault positioning of a distribution network.
For the phase current break variable, a distribution network low current grounding system is specifically taken as an example for explanation, and when a single-phase grounding fault occurs, the composition of the current in the system is shown in fig. 1. For the distribution network system before the fault occurs, the phase current of each line in the normal state consists of load current and line-to-ground capacitance current. The amplitude and the phase of the three-phase line current are still kept unchanged after the small current grounding system fails, so that the load current of each phase of the line does not change before and after the fault. Therefore, the phase current variation of each phase of each line is mainly reflected in the variation of the capacitance current to ground.
For each phase of the non-faulted line, the non-faulted phase of the faulted line, and the downstream segment of the faulted phase of the faulted line, the phase current break amount is:
wherein, Δ u is the sudden change of phase voltage of the phase of the line, and C is the capacitance value to ground of the phase of the line.
For the upstream section of the fault phase of the fault line, the phase current abrupt change quantity comprises the change quantity of the capacitance current to the ground, and also comprises the grounding current flowing through the grounding point, namely:
wherein, IkIs the ground current.
Meanwhile, the vector diagram analysis is carried out on the phase voltage abrupt change quantity related to the voltage abrupt change quantity, as shown in fig. 2, the three-phase voltage vector abrupt change quantity vectors of all lines are completely the same after the single-phase earth fault occurs, and the three-phase voltage vector abrupt change quantity vectors are zero sequence voltages, namely delta ua=Δub=Δuc=u0. Therefore, in conjunction with the characteristics associated with the phase voltage abrupt change, the characteristics of the phase current abrupt change may be summarized as follows:
for the non-fault line and the downstream of the fault line, the three-phase voltage sudden change quantity is kept consistent, so the corresponding phase current sudden change quantity is also kept consistent, namely the three-phase current sudden change quantity is equal in amplitude and consistent in waveform.
For the upstream of the fault line, the current abrupt change amount of the phase of the fault phase and the other two non-fault phases on the fault line is obviously different because the grounding current flows to the ground through a fault point on the fault phase.
Based on the characteristics, the single-phase earth fault of the power distribution network can be positioned. Meanwhile, for the phase current sudden change characteristic, the invention provides a waveform difference representation method.
For two waveforms A, B with the same sampling frequency, calculating the amplitude difference of the corresponding sampling points of the two waveforms at the same time and squaring, then accumulating the results in a power frequency period, and finally obtaining a result representing the difference of the two waveforms, as shown in the formula:
wherein N issRepresenting the number of sampling points, i, contained in a power frequency cycleA(n)、iBAnd (n) respectively corresponding to the sampling values of the two different waveforms at the nth sampling point.
By utilizing the waveform difference representation method in combination with phase current mutation fault characteristic analysis, the invention provides a distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference, as shown in fig. 3, the specific steps are as follows:
(1) after the single-phase earth fault of the power distribution network is judged, three-phase current data information of each section is obtained from a related current data acquisition device;
the obtained three-phase current data information of each section at least comprises phase current data of a non-fault normal operation state in two periods before the fault occurs to phase current data of a fault operation state in three periods after the fault occurs.
(2) Calculating the three-phase current abrupt change quantity of each section;
and calculating the three-phase current break variable corresponding to the second period after the fault of each section by the following formula:
wherein, Δ inThe phase current abrupt change quantity, t, corresponding to the nth sampling point of the second period after the fault is shown0At the approximate fault time, T is the power frequency period,Nsis the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
(3) Calculating the waveform difference of the phase current mutation quantity between every two phases of each section, and selecting the largest value from the three results as the characteristic quantity of the phase current mutation quantity difference of the fault non-fault phase of the section;
the waveform difference calculation method comprises the following steps:
wherein d isA-BRepresenting the waveform difference between waveform A and waveform B, iA(n)、iB(N) correspond to the sample values, N, of the waveform A, B at the nth sample point, respectivelysIs the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
(4) Comparing the difference characteristic quantities of phase current abrupt change quantities of all sections, judging the section with larger difference characteristic quantity as a fault upstream section, and judging the section with smaller difference characteristic quantity as a sound and fault downstream section;
the definition method of the difference characteristic quantity comprises the following steps: and judging the section with the difference characteristic quantity greater than 70% of the maximum difference characteristic quantity as a fault upstream section, and judging the section with the difference characteristic quantity less than or equal to 70% of the maximum difference characteristic quantity as a sound and fault downstream section.
(5) And (4) determining a specific fault section by combining the power distribution network topological structure according to the judgment result in the step 4.
Fault location is carried out according to the following logic, specifically: if the parts previously determined as the upstream sections are all adjacent sections, the part determined as the upstream section, which is positioned at the rearmost end (farthest from the bus) of the topology, is a faulty section; if a section determined to be an upstream section is partially dispersed or a majority of sections in the system are determined to be upstream sections, then a bus fault is considered to have occurred.
To further prove the correctness of the method of the present invention, a PSCAD simulation model as shown in FIG. 4 was established, i.e., a main transformer of a 35kV substation wired via Y/D was configured with a 10kV system in the form of a single bus, in which 8 different sections including the fault section were set up in total. In addition, the grounding mode of the system is adjusted in a mode that a grounding transformer is connected to a bus, and the grounding mode of the whole system is determined to be ungrounded or grounded through an arc suppression coil by changing the grounding mode of the star-shaped side of the grounding transformer.
The specific simulation and line equipment parameters are as follows:
the system frequency is 50Hz, the simulation duration is 2s, the section 2 generates C-phase single-phase ground fault in the middle section at the moment of 0.5s, the phase current sampling points are all arranged at the front end of each section, the simulation and sampling frequency is 50kHz, wherein:
a circuit: the line types in the system comprise pure overhead, pure cable and cable overhead mixed lines, and are specifically built by a frequency correlation model;
a main transformer: sN2MVA, Y/D wiring;
a distribution transformer: sN0.5MVA, D/Yn wiring;
loading: the load capacity accounts for 80% of the distribution transformer capacity, and the power factor is 85%;
an arc suppression coil: when the system is a system grounded through an arc suppression coil, an overcompensation mode is adopted, and the degree of compensation is 10%.
In the simulation model, when the system grounding mode is that the neutral point is grounded through the arc suppression coil, a metallic grounding fault with a fault initial phase angle of 90 ° occurs at the fault point, the waveforms of the three-phase current abrupt change quantities of the fault section 2 and the non-fault section 6 can be obtained as shown in fig. 5 and 6 according to the process two, and simultaneously, the simulation is performed under three different systems and typical fault conditions that the system is a neutral point ungrounded system, the grounding point transition resistance is 200 ohms, and the fault initial phase angle is 0 °, so that the line difference characteristic quantity and the positioning result shown in table 1 can be respectively obtained, and the current unit in the waveforms and the calculation result is kA.
In order to further highlight the superiority of the method, besides the difference calculation of the phase current mutation amount of the second period after the fault selected in the specific embodiment, the calculation and line selection results of the 3 rd and 4 th periods after the fault are also additionally displayed.
TABLE 1
As can be seen from fig. 5 and 6, the simulation results are consistent with the previous characterization summary for the phase current inrush variables and are applicable for any transient steady state phase after the fault occurs. Meanwhile, as can be seen from the data and results in table 1, the fault non-fault phase difference method provided by the invention can show obvious numerical difference for the upstream of the fault line, the downstream of the fault line and the non-fault line under various system types and fault conditions, and has very high positioning sensitivity and reliability.

Claims (6)

1. A distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference is characterized by comprising the following steps:
(1) judging that a single-phase earth fault occurs in the power distribution network, and acquiring three-phase current data of each section from a related current data acquisition device;
(2) calculating the three-phase current abrupt change quantity of each section;
(3) calculating the waveform difference of the phase current mutation quantity between every two phases of each section, and selecting the maximum value from the three results as the characteristic quantity of the phase current mutation quantity difference of the fault phase and the non-fault phase of the section;
(4) comparing the phase current mutation quantity difference characteristic quantities of all sections, judging the section with larger difference characteristic quantity as a fault upstream section, and judging the section with smaller difference characteristic quantity as a sound and fault downstream section;
(5) and (4) determining a specific fault section by combining the power distribution network topological structure according to the judgment result in the step 4.
2. The distribution network single-phase ground fault location method based on the difference between the current mutation quantities of the faulted phase and the non-faulted phase according to claim 1, wherein the three-phase current data information of each section obtained in step 1 at least comprises phase current data of a non-faulted normal operation state in two cycles before the fault occurs to phase current data of a faulted operation state in three cycles after the fault occurs.
3. The distribution network single-phase earth fault location method based on the difference between the current jump quantities of the fault phase and the non-fault phase according to claim 1, wherein in the step 2, a calculation formula of the three-phase current jump quantity after the fault of each section is given as follows:
wherein, Δ inRepresents the phase current abrupt change, t, corresponding to the nth sampling point in the period after the fault0At the approximate time of failure, T is the power frequency period, NsIs the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
4. The distribution network single-phase earth fault location method based on the phase current jump quantity difference between the fault phase and the non-fault phase according to claim 1, wherein in the step 3, the waveform difference calculation method comprises the following steps:
wherein d isA-BRepresenting the waveform difference between waveform A and waveform B, iA(n)、iB(N) correspond to the sample values, N, of the waveform A, B at the nth sample point, respectivelysIs the number of sampling points contained in a power frequency period, n is an integer and is not less than 0<Ns
5. The distribution network single-phase earth fault location method based on the difference between the phase current mutation of the fault phase and the phase current mutation of the non-fault phase as claimed in claim 1, wherein in the step 4, the definition method of the difference characteristic quantity is as follows: and judging the section with the difference characteristic quantity greater than 70% of the maximum difference characteristic quantity as a fault upstream section, and judging the section with the difference characteristic quantity less than or equal to 70% of the maximum difference characteristic quantity as a sound and fault downstream section.
6. The distribution network single-phase earth fault location method based on the difference of the current mutation of the fault phase and the non-fault phase according to claim 1, wherein in the step 5, fault location is performed according to the following logic:
if the parts previously determined as the upstream sections are all adjacent sections, the part determined as the upstream section at the last end of the topological structure is a fault section;
if the sections are determined to be partially distributed or the majority of the sections in the system are determined to be upstream sections, the bus fault is determined to occur.
CN201911010569.5A 2019-10-23 2019-10-23 Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference Pending CN110703040A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911010569.5A CN110703040A (en) 2019-10-23 2019-10-23 Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911010569.5A CN110703040A (en) 2019-10-23 2019-10-23 Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference

Publications (1)

Publication Number Publication Date
CN110703040A true CN110703040A (en) 2020-01-17

Family

ID=69201288

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911010569.5A Pending CN110703040A (en) 2019-10-23 2019-10-23 Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference

Country Status (1)

Country Link
CN (1) CN110703040A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112255499A (en) * 2020-10-10 2021-01-22 重庆大学 Phase current amplitude based power distribution network disconnection fault positioning and identifying method and system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103197203A (en) * 2013-03-29 2013-07-10 昆明理工大学 Fault line selection method based on time domain waveform correlation analysis of three-phase current breaking variable
CN104865496A (en) * 2015-04-28 2015-08-26 国家电网公司 Distribution network line fault segment positioning method based on differential offset
CN105842583A (en) * 2016-03-25 2016-08-10 西安交通大学 Distribution network single-phase grounding section positioning method based on fault phase voltage and current abrupt change
CN106154116A (en) * 2016-08-09 2016-11-23 国电南瑞科技股份有限公司 A kind of distribution net work earthing fault localization method
CN106646139A (en) * 2016-12-30 2017-05-10 华北电力大学 Method for positioning faults of power distribution network based on amplitude analysis of three-phase current

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103197203A (en) * 2013-03-29 2013-07-10 昆明理工大学 Fault line selection method based on time domain waveform correlation analysis of three-phase current breaking variable
CN104865496A (en) * 2015-04-28 2015-08-26 国家电网公司 Distribution network line fault segment positioning method based on differential offset
CN105842583A (en) * 2016-03-25 2016-08-10 西安交通大学 Distribution network single-phase grounding section positioning method based on fault phase voltage and current abrupt change
CN106154116A (en) * 2016-08-09 2016-11-23 国电南瑞科技股份有限公司 A kind of distribution net work earthing fault localization method
CN106646139A (en) * 2016-12-30 2017-05-10 华北电力大学 Method for positioning faults of power distribution network based on amplitude analysis of three-phase current

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112255499A (en) * 2020-10-10 2021-01-22 重庆大学 Phase current amplitude based power distribution network disconnection fault positioning and identifying method and system
CN112255499B (en) * 2020-10-10 2021-09-07 重庆大学 Phase current amplitude based power distribution network disconnection fault positioning and identifying method and system

Similar Documents

Publication Publication Date Title
CN101551432B (en) Power distribution network fault positioning method
CN100387999C (en) Circuit fault directional detecting and protecting method for power supply system
CN100530883C (en) Route selection method for single-phase ground fault of two-phase TA power distribution network
WO2014101656A1 (en) Method for monitoring insulation state of high-voltage power grid of coal mine
CN111007427B (en) Distribution line single-phase earth fault line selection method and computer readable storage medium
CN110703040A (en) Distribution network single-phase earth fault positioning method based on fault phase and non-fault phase current mutation difference
CN109324269B (en) Distribution network single-phase line break fault identification method based on distributed measurement
CN105974254B (en) The temporary stable state selection method of comprehensive weight is calculated based on voltage
CN101436776A (en) Grounding and line selection method for low current grounding system
CN104865498B (en) Arc suppression coil earthing system single-phase ground fault distance measuring method based on parameter identification
CN104280663A (en) Online monitoring and line selecting method for single-phase earth faults of small current grounding system
CN109633364B (en) Mutual inductor winding and fuse fault assessment method, device and equipment
CN109444666B (en) Power distribution network single-phase high-blocking line fault identification method and device
CN109001589B (en) Line parameter time domain calculation method based on non-full-phase operation fault recording data
Naidu et al. An accurate fault location method for radial distribution system using one terminal data
Shilong et al. Fault line selection of single phase grounding fault in small-current ground system based on reactive current
CN201038753Y (en) Stable state zero-sequence current boosting device
Nan et al. A new method of measuring capacitance current in non-effective grounding power system
Zhou Research on Neutral Voltage Offset and Its Influencing Factors of 20kV Small Resistance Grounding System
CN107064717A (en) Using the distribution earthing wire-selecting method of recombination current phase-detection
Lu et al. A novel location method for single-phase grounding fault in small current grounding distribution network based on difference of phase current fault component between fault and non-fault phases
Kang et al. New fault location technique for double-circuit transmission lines based on sparse current measurements
CN210534261U (en) Large-current fault line selection system
CN111983510A (en) Phase voltage and current break variable-based single-phase earth fault phase selection method and system
Liu Faulted feeder identification and location for a single line-to-ground fault in ungrounded distribution system based on principal frequency component

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination