CN111812452A - CT polarity self-correction method and system for low-current grounding line selection device - Google Patents
CT polarity self-correction method and system for low-current grounding line selection device Download PDFInfo
- Publication number
- CN111812452A CN111812452A CN202010527515.2A CN202010527515A CN111812452A CN 111812452 A CN111812452 A CN 111812452A CN 202010527515 A CN202010527515 A CN 202010527515A CN 111812452 A CN111812452 A CN 111812452A
- Authority
- CN
- China
- Prior art keywords
- fault line
- polarity
- branch
- suspected fault
- sequence current
- 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.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/175—Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/72—Testing of electric windings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/02—Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
-
- Y—GENERAL 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
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS 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
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a CT polarity self-correction method and a system for a low-current grounding line selection device, which comprises the following steps: acquiring the transient and steady state information of zero sequence current of each branch circuit in a single-phase earth fault state; determining a suspected fault line according to the transient and stable state information of the zero sequence current of each branch; performing a trip operation on the suspected fault line; correcting the CT polarity of the suspected fault line according to the tripping operation result; acquiring zero-sequence current transient data of a suspected fault line after tripping operation; judging whether the zero-sequence current steady-state value of each branch except the suspected fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficient of each branch except the suspected fault line and the suspected fault line according to the zero-sequence current transient data of the suspected fault line; and correcting the CT polarity of each branch except the suspected fault line according to the direction coefficient. The invention realizes CT polarity self-correction based on a mode of adopting zero sequence CT to collect zero sequence current of each branch, and is convenient to operate.
Description
Technical Field
The invention relates to the technical field of low-current grounding systems, in particular to a CT polarity self-correction method and system for a low-current grounding line selection device.
Background
The faults of the power distribution network in the whole power system are the most, wherein the single-phase earth faults are the most, the total number of the faults is more than 80%, and the fault line can be correctly judged and isolated after the single-phase earth faults occur, so that the novel small-current earth line selection device with the tripping function is particularly important, and is gradually widely applied to the power distribution network.
At present, small current grounding line selection methods are various, but the principle mainly includes an active method and a passive method, wherein the active method needs to be additionally provided with signal injection equipment, and judgment is carried out by utilizing the variable quantity or the threshold value of the zero sequence current of each branch circuit; the passive method mainly depends on voltage and current analog quantity signals acquired by the device, and utilizes the amplitude comparison of zero sequence current of each branch circuit or the relation between the zero sequence current of the bus to analyze so as to judge the fault line. However, no matter which line selection principle is adopted, whether the polarity of the zero sequence CT is correct or not directly influences the line selection accuracy of the small-current grounding line selection device.
In view of the characteristic that the zero sequence current value is very small when the system normally operates, the polarity of the CT cannot be accurately judged through actually measured information of the device, and the consistency check of the polarity of the zero sequence CT is not allowed to be carried out on the power failure of the switch cabinet under a plurality of conditions on site, so that the polarities of signals collected by the device cannot be unified directly, and the accuracy rate of line selection is influenced.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a CT polarity self-correction method and a CT polarity self-correction system for a low-current grounding line selection device, so as to solve the problem that the CT polarity is difficult to check in the prior art.
In order to achieve the technical purpose, the invention adopts the technical scheme that:
a small current grounding line selection device CT polarity self-correction method comprises the following steps:
acquiring the transient and steady state information of zero sequence current of each branch circuit in a single-phase earth fault state;
determining a suspected fault line according to the transient and stable state information of the zero sequence current of each branch;
performing a trip operation on the suspected fault line;
correcting the CT polarity of the suspected fault line according to the tripping operation result;
acquiring zero-sequence current transient data of a suspected fault line after tripping operation;
judging whether the zero-sequence current steady-state value of each branch except the suspected fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficient of each branch except the suspected fault line and the suspected fault line according to the zero-sequence current transient data of the suspected fault line;
and correcting the CT polarity of each branch except the suspected fault line according to the direction coefficient.
Further, the CT polarity correction method for the suspected fault line includes:
and judging whether the ground fault of the suspected fault line disappears after the tripping operation, if so, correcting the CT polarity, and if not, modifying the CT polarity parameter of the fault line, and correcting the CT polarity.
Further, the method for acquiring the transient data of the zero-sequence current of the suspected fault line includes:
and judging whether the ground fault disappears after the tripping operation, if so, acquiring zero-sequence current transient data of the suspected fault line as the fault line, otherwise, acquiring actual zero-sequence current transient data of the suspected fault line and taking the data after negation as the zero-sequence current transient data required to be acquired.
Further, the calculation formula of the direction coefficient is as follows:
in the formula (I), the compound is shown in the specification,DCoethe directional coefficients of branch i and branch k,is the zero sequence current transient data of the branch circuit i,the transient state data of the zero sequence current of the branch k is shown, and N is the length of a transient state data window.
Further, the CT polarity correction method for each branch except the suspected fault line is as follows:
for any branch outside the suspected fault line, if the direction coefficient is smaller than 0, the CT polarity of the branch is correct without correction; if the direction coefficient is larger than 0, the CT polarity of the branch is wrong, the CT polarity parameter is modified, and the CT polarity of the branch is corrected.
A low current ground selection CT polarity self-correction system, the system comprising:
a first obtaining module: the method comprises the steps of obtaining transient and steady state information of zero sequence current of each branch circuit in a single-phase earth fault state;
a confirmation module: the system is used for determining a suspected fault line according to the transient and steady state information of the zero sequence current of each branch;
an execution module: the system is used for performing a tripping operation on the suspected fault line; (ii) a
A first correction module: the system is used for correcting the CT polarity of the suspected fault line according to the tripping operation result;
a second obtaining module: the method comprises the steps of obtaining zero sequence current transient data of a suspected fault line after tripping operation;
a judging module: the method is used for judging whether the zero-sequence current steady-state value of each branch except the suspected fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficient of each branch except the suspected fault line and the suspected fault line according to the zero-sequence current transient data of the suspected fault line;
a second correction module: and the CT polarity of each branch except the suspected fault line is corrected according to the direction coefficient.
A low current grounded line selector CT polarity self-correction system, the system comprising a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate according to the instructions to perform the steps of the method described above.
A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method described above.
Compared with the prior art, the invention has the following beneficial technical effects:
on the premise of executing tripping operation after single-phase earth fault, the fault line is used as CT standard polarity, the relation between the zero sequence current steady state value of each branch and an effective measurement threshold value is firstly compared, then the zero sequence current transient state quantity direction of each branch and the fault line is transversely contrasted and analyzed, whether the CT polarity of each branch is correct or not is judged, and CT polarity self-correction is realized; the invention does not need to check the polarity consistency of zero sequence CT when the switch cabinet is powered off, and is suitable for small current grounding systems, including a neutral point ungrounded system and a resonance grounding system.
Drawings
Fig. 1 is a zero sequence current transient characteristic curve of a single-phase earth fault of a small current grounding system;
fig. 2 is a logic flow diagram of a CT polarity self-correction method of a low-current grounding line selection device.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
According to theoretical analysis, when a single-phase earth fault occurs in a small-current grounding system, the transient state quantity of the zero-sequence current is not affected by the compensation of the inductance current of the arc suppression coil, and the transient direction of the zero-sequence current of a fault line is always opposite to that of a non-fault line. Taking a single-phase grounding fault of the line 1 as an example, a zero-sequence current transient characteristic curve generated in the single-phase grounding process is shown in fig. 1, and the transient characteristics of the zero-sequence current collected by the CT1# on the fault line and the CT2# and the CT3# on the non-fault line are not similar and have approximately opposite directions; the transient characteristics of zero sequence currents collected by a CT2# and a CT3# on a non-fault line are similar, and the directions are the same.
As shown in fig. 2, a method for self-correcting the CT polarity of a low-current grounding line selection device includes the following steps:
the method comprises the following steps: when the system has single-phase earth fault, the transient and steady state information of the zero sequence current of each branch is obtained;
Step two: judging a suspected fault line according to the transient and steady state information of the zero sequence current, and executing tripping operation on the suspected fault line k, and opening a switch of the line k;
step three: if the grounding fault disappears after the switch of the line k is opened, the line k is shown as an actual fault line, the CT polarity is correct, and the zero-sequence current transient data is taken(ii) a If the grounding fault does not disappear after the switch of the line k is opened, the line k is represented as a non-fault line, the CT polarity is wrong, and the CT polarity parameter is modifiedInverting the k zero-sequence current transient data of the line, i.e.;
Step four: judging the zero sequence current steady state value of each branchWhether or not it is greater than the effective measurement threshold value;
Step five: when branch i zero sequence current steady state valueAnd then, taking the branch k as the standard polarity of CT, and carrying out transverse contrastive analysis on the transient state information of the branch i and the branch k, wherein the formula is as follows:
in the formulaDCoeThe coefficients of the direction of the branch i and the branch k,is the zero sequence current transient data of the branch circuit i,the zero sequence current transient data of the branch k is obtained, and N is the length of a transient data window;
if the steady state value of the branch i zero sequence current is not larger than the effective measurement threshold valueIf so, the polarity of the CT of the branch is not judged and corrected.
Step six: according to the direction coefficients of the branch i and the branch k, the automatic correction of the polarity of the branch CT is realized:
(A1) coefficient of current directionDCoeWhen the current is less than 0, the polarity of the CT of the i branch is correct;
(A2) when in useCoefficient of directionDCoeAnd when the current is more than 0, the CT polarity of the i branch is wrong, and the CT polarity parameter is modified.
A low current ground selection CT polarity self-correction system, the system comprising:
a first obtaining module: the fault line acquisition module is used for acquiring fault lines in each branch;
an execution module: for performing a trip operation on the faulty line;
a first correction module: the CT polarity correction module is used for correcting the CT polarity of the fault line according to the tripping operation result;
a second obtaining module: the fault circuit transient state quantity acquisition module is used for acquiring the transient state quantity of a fault circuit after tripping operation;
a judging module: the method is used for judging whether the zero sequence current steady state value of each branch outside the fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficients of each branch outside the fault line and the fault line according to the transient state quantity of the fault line;
a second correction module: and the CT polarity of each branch except the fault line is corrected according to the direction coefficient.
A low current grounded line selector CT polarity self-correction system, the system comprising a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate according to the instructions to perform the steps of the method described above.
A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method described above.
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.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. A CT polarity self-correction method for a low-current grounding line selection device is characterized by comprising the following steps:
acquiring the transient and steady state information of zero sequence current of each branch circuit in a single-phase earth fault state;
determining a suspected fault line according to the transient and stable state information of the zero sequence current of each branch;
performing a trip operation on the suspected fault line;
correcting the CT polarity of the suspected fault line according to the tripping operation result;
acquiring zero-sequence current transient data of a suspected fault line after tripping operation;
judging whether the zero-sequence current steady-state value of each branch except the suspected fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficient of each branch except the suspected fault line and the suspected fault line according to the zero-sequence current transient data of the suspected fault line;
and correcting the CT polarity of each branch except the suspected fault line according to the direction coefficient.
2. The CT polarity self-correction method for the low-current grounding line selection device according to claim 1, wherein the CT polarity correction method for the suspected fault line comprises the following steps:
and judging whether the ground fault of the suspected fault line disappears after the tripping operation, if so, correcting the CT polarity, and if not, modifying the CT polarity parameter of the suspected fault line, and correcting the CT polarity.
3. The method for self-correcting the polarity of the CT of the small-current grounding line selection device according to claim 1, wherein the method for obtaining the transient data of the zero-sequence current of the suspected fault line comprises:
and judging whether the ground fault disappears after the tripping operation, if so, acquiring zero-sequence current transient data of the suspected fault line as the fault line, otherwise, acquiring actual zero-sequence current transient data of the suspected fault line and taking the data after negation as the zero-sequence current transient data required to be acquired.
4. The method as claimed in claim 3, wherein the directional coefficient is calculated as follows:
5. The method as claimed in claim 1, wherein the CT polarity correction method for each branch other than the suspected fault line is as follows:
for any branch outside the suspected fault line, if the direction coefficient is smaller than 0, the CT polarity of the branch is correct without correction; if the direction coefficient is larger than 0, the CT polarity of the branch is wrong, the CT polarity parameter is modified, and the CT polarity of the branch is corrected.
6. A small current grounding line selection device CT polarity self-correction system is characterized by comprising:
a first obtaining module: the method comprises the steps of obtaining transient and steady state information of zero sequence current of each branch circuit in a single-phase earth fault state;
the fault line initial judgment module: the system is used for determining a suspected fault line according to the transient and steady state information of the zero sequence current of each branch;
an execution module: the system is used for performing a tripping operation on the suspected fault line; (ii) a
A first correction module: the system is used for correcting the CT polarity of the suspected fault line according to the tripping operation result;
a second obtaining module: the method comprises the steps of obtaining zero sequence current transient data of a suspected fault line after tripping operation;
a judging module: the method is used for judging whether the zero-sequence current steady-state value of each branch except the suspected fault line is larger than an effective measurement threshold value or not, and if so, calculating the direction coefficient of each branch except the suspected fault line and the suspected fault line according to the zero-sequence current transient data of the suspected fault line;
a second correction module: and the CT polarity of each branch except the suspected fault line is corrected according to the direction coefficient.
7. A CT polarity self-correction system of a low-current grounding line selection device is characterized by comprising a processor and a storage medium;
the storage medium is used for storing instructions;
the processor is configured to operate in accordance with the instructions to perform the steps of the method according to any one of claims 1 to 5.
8. Computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 5.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010527515.2A CN111812452B (en) | 2020-06-11 | 2020-06-11 | CT polarity self-correction method and system for low-current grounding line selection device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010527515.2A CN111812452B (en) | 2020-06-11 | 2020-06-11 | CT polarity self-correction method and system for low-current grounding line selection device |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111812452A true CN111812452A (en) | 2020-10-23 |
CN111812452B CN111812452B (en) | 2023-02-21 |
Family
ID=72846542
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202010527515.2A Active CN111812452B (en) | 2020-06-11 | 2020-06-11 | CT polarity self-correction method and system for low-current grounding line selection device |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111812452B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114200354A (en) * | 2022-02-16 | 2022-03-18 | 广东电网有限责任公司肇庆供电局 | Zero sequence CT polarity online detection method, system and equipment |
CN118137435A (en) * | 2024-04-30 | 2024-06-04 | 山东德源电力科技股份有限公司 | Magnetic control switch control method and system based on mechanical lock catch |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030091267A (en) * | 2002-05-27 | 2003-12-03 | 엘지전선 주식회사 | Over current relay using zero-sequence current of ground wire |
CN101154807A (en) * | 2007-10-11 | 2008-04-02 | 天津大学 | Self-adaption route selection method for single-phase ground fault of power distribution network based on transient zero sequence current |
CN104062543A (en) * | 2014-06-27 | 2014-09-24 | 中广核工程有限公司 | Zero sequence differential protection polarity verification method and zero sequence differential protection calibration method |
CN107976612A (en) * | 2018-01-16 | 2018-05-01 | 济南置真电气有限公司 | A kind of polarity check method based on singlephase earth fault line tripping information |
CN108196214A (en) * | 2017-12-12 | 2018-06-22 | 神华集团有限责任公司 | Feeder line zero sequence current mutual inductor CT polarity check methods and device |
CN109031179A (en) * | 2018-07-04 | 2018-12-18 | 云南电网有限责任公司 | Main transformer CT polarity and protection direction-adaptive method of calibration |
CN208588788U (en) * | 2018-07-04 | 2019-03-08 | 云南电网有限责任公司 | The adaptive calibration equipment of CT polarity for route |
CN110907758A (en) * | 2019-12-06 | 2020-03-24 | 国电南瑞科技股份有限公司 | Small current ground fault line selection method covering CT polarity self-correction |
-
2020
- 2020-06-11 CN CN202010527515.2A patent/CN111812452B/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20030091267A (en) * | 2002-05-27 | 2003-12-03 | 엘지전선 주식회사 | Over current relay using zero-sequence current of ground wire |
CN101154807A (en) * | 2007-10-11 | 2008-04-02 | 天津大学 | Self-adaption route selection method for single-phase ground fault of power distribution network based on transient zero sequence current |
CN104062543A (en) * | 2014-06-27 | 2014-09-24 | 中广核工程有限公司 | Zero sequence differential protection polarity verification method and zero sequence differential protection calibration method |
CN108196214A (en) * | 2017-12-12 | 2018-06-22 | 神华集团有限责任公司 | Feeder line zero sequence current mutual inductor CT polarity check methods and device |
CN107976612A (en) * | 2018-01-16 | 2018-05-01 | 济南置真电气有限公司 | A kind of polarity check method based on singlephase earth fault line tripping information |
CN109031179A (en) * | 2018-07-04 | 2018-12-18 | 云南电网有限责任公司 | Main transformer CT polarity and protection direction-adaptive method of calibration |
CN208588788U (en) * | 2018-07-04 | 2019-03-08 | 云南电网有限责任公司 | The adaptive calibration equipment of CT polarity for route |
CN110907758A (en) * | 2019-12-06 | 2020-03-24 | 国电南瑞科技股份有限公司 | Small current ground fault line selection method covering CT polarity self-correction |
Non-Patent Citations (3)
Title |
---|
乔中伟: "母线差动保护一次升流方法研究", 《贵州电力技术》 * |
刘子清: "判断线路零序方向继电器接线的方法", 《继电器》 * |
李功新: "相轨迹用于小电流接地系统单相接地故障检测与选线", 《高压电器》 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114200354A (en) * | 2022-02-16 | 2022-03-18 | 广东电网有限责任公司肇庆供电局 | Zero sequence CT polarity online detection method, system and equipment |
CN114200354B (en) * | 2022-02-16 | 2022-04-19 | 广东电网有限责任公司肇庆供电局 | Zero sequence CT polarity online detection method, system and equipment |
CN118137435A (en) * | 2024-04-30 | 2024-06-04 | 山东德源电力科技股份有限公司 | Magnetic control switch control method and system based on mechanical lock catch |
CN118137435B (en) * | 2024-04-30 | 2024-07-02 | 山东德源电力科技股份有限公司 | Magnetic control switch control method and system based on mechanical lock catch |
Also Published As
Publication number | Publication date |
---|---|
CN111812452B (en) | 2023-02-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2113778B1 (en) | System and method for determining location of phase-to-phase fault or three-phase fault | |
EP0876620B1 (en) | Method of detecting and locating a high-resistance earth fault in an electric power network | |
CN111812452B (en) | CT polarity self-correction method and system for low-current grounding line selection device | |
Ferreira et al. | A unified impedance-based fault location method for generalized distribution systems | |
CN111812451B (en) | Phase current transient fault component-based distributed line selection method for power distribution network | |
CN111426908B (en) | Single-phase earth fault protection method, device and system for small current earthing system | |
CN105552838A (en) | Standardized graphic similarity matching identification-based zero-sequence differential protection algorithm for transformer | |
US11916367B2 (en) | Method and device for estimating source impedances across one or more transmission lines | |
CN109286202B (en) | Large-scale inversion type power supply grid-connected tie line current differential protection method, device and system | |
CN111257698A (en) | Low-current grounding power grid continuous line selection system based on impedance change detection | |
CN110954743A (en) | Distributed wave recording device and low-current grounding line selection method | |
CN101951010A (en) | Ground protection method for small-current ground system | |
CN111398871A (en) | Device and method for checking polarity of zero sequence current transformer | |
CN112379302B (en) | Small-current ground fault protection method, device and system for integrating time-frequency domain information | |
CN117741343A (en) | Single-phase earth fault transition resistance calculation method, fault judgment method and system | |
CN111736107B (en) | CT (computed tomography) disconnection detection method, system and medium based on sequence current phase comparison | |
CN115280625A (en) | Detecting electrical faults within a monitored area of an electrical transmission line | |
CN112653105A (en) | High-voltage transmission line backup protection method and device based on current information reconstruction | |
CN110927516B (en) | Power distribution network single-phase earth fault identification method and system based on grounding transformer tap grounding | |
CN110879332A (en) | Single-phase earth fault phase selection method suitable for small current grounding system | |
CN116148599A (en) | Kurtosis and skewness coefficient-based high-resistance ground fault diagnosis protection method and device | |
CN111521951B (en) | Method and device for preventing misjudgment of CT (current transformer) broken line caused by grounding fault of control winding side of valve-controlled reactor and storage medium | |
CN111025080B (en) | Method and system for determining fault line based on station domain information | |
CN113725816A (en) | Transformer differential protection method and system based on current phasor difference 2 norm | |
Mohamad et al. | Detection of fault during power swing in test system interconnected with DG |
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 | ||
GR01 | Patent grant | ||
GR01 | Patent grant |