CN109061385B - Single-phase ground fault detection and location isolation method based on transient steady state information - Google Patents
Single-phase ground fault detection and location isolation method based on transient steady state information Download PDFInfo
- Publication number
- CN109061385B CN109061385B CN201810932003.7A CN201810932003A CN109061385B CN 109061385 B CN109061385 B CN 109061385B CN 201810932003 A CN201810932003 A CN 201810932003A CN 109061385 B CN109061385 B CN 109061385B
- Authority
- CN
- China
- Prior art keywords
- fault
- node
- zero
- area
- nodes
- 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.)
- Active
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
- 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Locating Faults (AREA)
Abstract
本发明公开了一种基于暂稳态信息的单相接地故障检测及定位隔离方法，以稳态量突变为启动判据，实现对暂态特征量的提取；并将缓存暂态数据进行分时段处理，分非故障时段和故障时段，提取不同时段的状态特征，进行对比分析，精确定位故障初始时刻；然后截取故障初始阶段数据，配置不同可信度因子，进行向量分析，并辅助稳态量信息进行故障准确判别；最后以对等通信方式交互故障信息或是将故障信息上送主站集中处理方式实现故障准确定位及隔离。本发明适用于不同中性点接地方式配电网系统的单相接地故障检测、定位及隔离，极大地提高了小电流接地系统单相接地故障检测成功率，且一套定值适用于各种方式接地系统，应用前景良好。
The invention discloses a single-phase grounding fault detection and location isolation method based on transient steady state information, which takes the sudden change of steady state quantity as the starting criterion to realize the extraction of transient characteristic quantity; Processing, divides the non-fault period and the fault period, extracts the state characteristics of different periods, conducts comparative analysis, and accurately locates the initial time of the fault; then intercepts the data at the initial stage of the fault, configures different reliability factors, conducts vector analysis, and assists steady state variables. The fault information can be accurately identified; finally, the fault information can be exchanged by peer-to-peer communication or sent to the master station for centralized processing to achieve accurate fault location and isolation. The invention is suitable for single-phase grounding fault detection, location and isolation of distribution network systems with different neutral point grounding methods, which greatly improves the success rate of single-phase grounding fault detection in low-current grounding systems, and a set of fixed values is suitable for various Mode grounding system, the application prospect is good.
Description
Technical Field
The invention belongs to the technical field of power distribution networks, and particularly relates to a single-phase earth fault detection and positioning isolation method based on transient and steady state information.
Background
The detection of single-phase earth faults in low-current earthing systems, in particular in resonant earthing power distribution networks (the neutral point is earthed via an arc suppression coil), has been regarded as a worldwide problem. People develop various detection methods successively, but the fault detection accuracy is not ideal enough, which may cause short-time power loss of a non-fault line and longer time for recovering power supply from faults.
Overvoltage generated by single-phase earth fault of a low-current grounding system easily causes insulation breakdown of a non-fault phase, and two-phase earth fault is caused. When a cable line has a ground fault, a long-time grounding arc current may burn through the insulation of a fault point, so that the cable line develops into an interphase short-circuit fault. Thus, long-term belt failure operation may extend the failure range and severity, causing significant economic loss.
With the social development and the improvement of the living standard of people, higher and higher requirements are provided for the power supply quality, and the problem of short-time power failure has attracted great attention of people. Therefore, it is necessary to solve the problems of accurate positioning and isolation of the single-phase earth fault of the low-current grounding system so as to improve the power supply quality and the safe operation level of the power distribution network.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a single-phase earth fault detection and positioning isolation method based on transient and steady state information, which can be suitable for accurate judgment, quick positioning and isolation of single-phase earth faults of power distribution networks with different neutral point grounding modes, and improves the success rate of single-phase earth fault detection of the power distribution networks, particularly a small-current grounding system, so as to reduce the power failure range, shorten the power failure time and ensure the power supply quality, and the technical scheme adopted by the invention is as follows:
a single-phase earth fault detection and positioning isolation method based on transient and steady state information comprises the following steps:
1) acquiring zero-sequence voltage and zero-sequence current in real time at a high sampling rate (not less than 3200HZ), and circularly caching the sampled data, wherein the length of a buffer area is N cycles;
2) calculating zero sequence voltage, zero sequence current fundamental wave amplitude or a true effective value in real time, starting counting when the zero sequence voltage is greater than a preset threshold value, and performing snapshot storage on a current buffer area after M cycle sampling points are counted;
3) carrying out time-phased processing on the N cycles of data in the buffer area after the snapshot is stored, identifying and dividing the data into non-fault time periods and fault time periods, extracting state characteristics of the non-fault time periods and the fault time periods, carrying out comparative analysis, and accurately positioning the initial moment of the fault;
4) intercepting a specific number of sampling points in the snapshot buffer area from the initial moment of the fault, wherein the specific number of points is comprehensively determined according to the magnitude and polarity of the zero-sequence voltage and the zero-sequence current and the set judgment number;
5) determining the location of the fault with respect to a node (the node assigning a switching device in the grid or a terminal device installed at the switch) includes:
5a) configuring different credibility factors for the intercepted data, constructing a zero sequence voltage vector and a zero sequence current vector, and judging faults through vector analysis, wherein the method specifically comprises the following steps:
the constructed zero sequence voltage vector and the constructed current vector are respectively (x)1，x2，...，xk)、(y1，y2，...，yk)；
Wherein k is the number of points of the sampling points determined in the step 4);
x1，x2，...，xkthe zero sequence voltage sampling data after weighting processing, namely multiplying the intercepted zero sequence voltage sampling data by a credibility factor;
y1，y2，...，yksampling data of the zero-sequence current after weighting processing, namely multiplying the intercepted zero-sequence current sampling data by a credibility factor;
by vector dot multiplication (x)1，x2，...，xk)·(y1，y2，...，yk)＝x1*y1+x2*y2+…xk*ykJudging the positive and negative polarities of the result, if the result is negative, indicating that the fault point is an intra-area fault point (the fault node is at the downstream); the result is positive, then the point of failure is an out-of-range point of failure (failed node is upstream). (remark: zero sequence PT, CT are wired according to the set tide direction, and the fault in the region is the downstream fault of the node, and the fault outside the region is the upstream fault of the node).
5b) Calculating the phase relation between transient zero-sequence active power and steady zero-sequence voltage and current at the initial stage of the fault, performing comprehensive identification by combining a vector analysis result, and accurately judging the fault; from the initial moment of the fault, V (V is less than or equal to M) cycle data are selected backwards to calculate transient zero sequence active power, the active power is negative, and the fault point is at the downstream of the node (the fault in the region); active power is positive and the point of failure is upstream of the node (out-of-range failure). Counting the phase relation of the steady-state zero-sequence voltage and current, performing comprehensive identification by combining the vector analysis result and the active power analysis result, and accurately judging the fault
Through adjacent node to wait communication interaction trouble information or with each node trouble information upload main website centralized processing mode, confirm the fault area, then keep apart, resume the power supply, the fault area is confirmed specifically to be: the zero sequence PT and CT are connected in a set tide direction, the relationship between nodes is determined according to the set tide direction, and the adjacent nodes are divided into father nodes, child nodes and brother nodes, wherein the father nodes are arranged above the tide of the adjacent nodes, the child nodes are arranged below the tide of the adjacent nodes, and the brother nodes are called if the adjacent nodes and the current node have the same father nodes; if the downstream of the node is in fault, the child nodes are in fault, the area enclosed by the node and all the child nodes is a non-fault area, otherwise, the node is a fault area; if the upstream of the node fails, a father node also fails upstream or a brother node fails downstream, the node, all father nodes and brother nodes form a region which is a non-failure region, and otherwise, the node is a failure region.
The invention has the following beneficial effects: the method can be suitable for accurate discrimination and rapid positioning isolation of the single-phase earth fault in different neutral point grounding modes of the power distribution network, and improves the reliability of power supply.
Drawings
FIG. 1 is a flow chart of single-phase earth fault detection based on transient and steady state information according to the present invention;
FIG. 2 is a single-phase earth fault location and isolation flow chart based on the real-time interaction of adjacent node information according to the present invention;
FIG. 3 is a typical urban distribution network system wiring diagram;
FIG. 4 is a wiring diagram of an overhead line power distribution network system;
fig. 5 is a bus outgoing wiring diagram of the substation.
Detailed Description
To further describe the technical features and effects of the present invention, the present invention will be further described with reference to the accompanying drawings and detailed description.
Referring to fig. 1 to 5 (each solid cuboid in fig. 2 to 5 represents a node), the configuration principle is: for an urban power distribution network, as shown in fig. 3, terminal equipment is installed at outgoing lines of a transformer substation and each ring main unit, and a communication network is laid; for the overhead line, as shown in fig. 4, terminal devices are installed at each switching point of the overhead line, and a communication network is laid; for the outgoing line of the low-voltage bus of the transformer substation, as shown in fig. 5, a centralized line selection terminal device is installed.
Primary equipment: and configuring a zero sequence PT (zero sequence voltage transformer) and a zero sequence CT (zero sequence current transformer), and wiring according to a set power flow direction.
The terminal equipment: the equipment such as a monitoring switch, a bus and the like collects zero sequence voltage and zero sequence current in real time at a high sampling rate, realizes the single-phase earth fault detection and positioning isolation method provided by the invention, and completes the accurate positioning and isolation of the single-phase earth fault. The single-phase earth fault detection process is shown in fig. 1, and the single-phase earth fault positioning isolation process based on the real-time interaction of the information of adjacent nodes (nodes assign switching devices in the power grid or terminal devices installed at switches) is shown in fig. 2. The method comprises the following specific steps:
step 1: the method comprises the steps of collecting zero sequence voltage and zero sequence current in real time at a high sampling rate (sampling is carried out at 64 points and more per cycle, namely, the sampling rate is not more than 3200HZ, the higher the sampling rate is, the more accurate the sampling rate is), and circularly caching the sampled data, wherein the length of a buffer area is N cycles; the sampling mode is carried out in a timing interruption mode, and frequency following processing is carried out, namely the interruption period is changed along with the frequency of the power grid.
Step 2: calculating zero sequence voltage, zero sequence current fundamental wave amplitude or true effective value point by point in the timed interruption, counting when the zero sequence voltage is larger than a preset threshold value, and after M cycles of sampling data are counted (the M cycles cover transient active power calculation cycles which are larger than V), carrying out snapshot storage on the current buffer area (namely, cutting off the current data and carrying out freezing like photographing).
And step 3: the method comprises the steps of carrying out time-sharing processing on N cycle (covering fault initial stage data) data in a snapshot buffer area, identifying and dividing non-fault time periods and fault time periods according to the sequence of sampling time, extracting state characteristics of the non-fault time periods and the fault time periods, carrying out comparative analysis, and accurately positioning the fault initial time.
And 4, step 4: from the initial moment of the fault, sampling data of a specific number of points in the snapshot buffer area is intercepted backwards, and the specific number is determined comprehensively according to the magnitude and polarity of the zero sequence voltage and the zero sequence current and the set judgment number of points.
And 5: determining a location of the fault relative to the node, comprising:
configuring different credibility factors for the intercepted data, constructing zero sequence voltage and zero sequence current vectors, and judging faults through vector analysis. The constructed zero sequence voltage current vector is assumed to be (x)1，x2，...，xk)、(y1，y2，...，yk) Wherein:
By vector dot multiplication (x)1，x2，...，xk)·(y1，y2，...，yk)＝x1*y1+x2*y2+…xk*yk
The positive and negative polarities of the result are judged, the result is negative, and the fault point is at the downstream of the node (in-zone fault); the result is positive, the point of failure is upstream of the node (out-of-range failure).
Configuring different credibility factors for intercepted data, constructing a zero-sequence voltage vector and a zero-sequence current vector, and judging a fault through vector analysis, namely selecting V (V is less than or equal to M) cycle data backwards from the initial moment of the fault to calculate transient zero-sequence active power, wherein when wiring is performed in the mode in the figure 2, the active power is negative, and a fault point is at the downstream of a node (a fault in a region); active power is positive and the point of failure is upstream of the node (out-of-range failure). And counting the phase relation of the steady-state zero-sequence voltage and current, performing comprehensive identification by combining a vector analysis result and an active power analysis result, and accurately judging the fault.
a) Step 6: the fault positioning method comprises the following steps: the zero sequence PT and the zero sequence CT are wired according to a set tide direction, as shown in figure 2;
b) determining the relationship among nodes according to the set tidal current direction, and dividing adjacent nodes into a father node (located above the tidal current), a child node (located below the tidal current) and a brother node (having a common father node), wherein the father node of the node 3 in FIG. 2 is 2, the child node is 4, and the brother node is 6;
c) if the downstream fault of the node (the currently detected node) and the downstream fault of a certain child node exist, the node and all the child nodes form a region which is a non-fault region, otherwise, the node is a fault region; if the upstream of the node fails, a father node also fails upstream or a brother node fails downstream, the node, all father nodes and brother nodes form a region which is a non-failure region, otherwise, the node is a failure region;
d) when the node communication is abnormal and can not be accurately positioned as a non-fault area, only the node is isolated;
e) when the node switch refuses to operate, tripping the adjacent node to isolate the fault and expanding the fault area treatment;
f) and after the area is determined to be a fault area, sending a tripping command to nodes in the area for fault isolation.
● for the low voltage bus of the transformer substation, the fault on the bus in the switching station, the distribution station and the ring main unit is opened and closed, and the terminal equipment directly determines whether the bus has the fault by using the method;
● for the ground fault on the main line/branch line of the overhead line and the urban distribution network (including cable network, hybrid network), when adopting the centralized processing mode, the fault information is sent to the main station, the main station adopts the method to locate the fault, and then the fault section is cut off by the remote control mode or the manual on-site operation mode to recover the power supply; when the fault location isolation is carried out by adopting a real-time interaction mode based on the adjacent node information, the distributed processing is carried out by utilizing a peer-to-peer communication technology, and the fault location isolation is completed on site.
The single-phase earth fault positioning and isolating method based on the adjacent node information real-time interaction mode is implemented as follows:
1) neighborhood partitioning, a neighborhood is a region bounded by a set of neighboring nodes, as shown by the regions identified in FIG. 2.
2) And carrying out intra-area fault information interaction according to the divided areas, namely carrying out information interaction between a single node and all adjacent nodes. In fig. 2, node 2 is in communication with nodes 1, 3, 6; node 3 communicates with nodes 2, 6, 4.
3) The communication mode adopts a peer-to-peer communication technology. GOOSE (generic object-oriented substation event) is a real-time application, and the communication delay is less than 4 ms; the GOOSE service is based on high-speed point-to-point (P2P) communication, supports point-to-multipoint transmission and event-driven transmission, has the advantages of high real-time performance, high reliability and the like, is suitable for real-time interactive sharing of information among multiple devices, and adopts GOOSE to carry out adjacent node information interaction.
4) The control flow is as shown in fig. 2, after the zero sequence overvoltage of the node is started, the fault information of the adjacent node is collected, the time delay is started, the fault section is positioned by the fault positioning method after the time delay is finished, after the fault area is determined, the fault area is directly cut off by the node in the fault area or cut off by a GOOSE jump mode, the rapid positioning and isolation of the fault are realized, then the load transfer (the load pre-judgment needs to be carried out, the overload is avoided) is carried out by the main station or the GOOSE remote control mode remote connection switch, and the power supply is recovered.
The fault location logic is the same regardless of the centralized processing mode of the master station or the distributed processing mode based on peer-to-peer communication, taking fig. 2 as an example:
in the area B, the nodes 1, 2, 3, 4, 5, and 6 are respectively determined as: downstream, upstream faults; and the fault area can be accurately positioned as an area B through the fault information of the neighborhood nodes.
In the area C, the nodes 1, 2, 3, 4, 5, and 6 are respectively determined as: downstream, upstream; and the fault area can be accurately positioned to be an area C through the fault information of the neighborhood nodes.
Bus faults (such as low-voltage buses of substations, buses in switchgears, ring main units and distribution stations) are similar to the faults in the area B in FIG. 2.
For overhead line power distribution networks and urban power distribution networks, as shown in fig. 3 and 4:
1. and a centralized processing mode of the master station. When a single-phase earth fault occurs at a certain point of a main line, the fault signals judged by terminal equipment on two sides of the fault point are opposite, namely one judges that the fault point is at the downstream (in-zone fault) and the other judges that the fault point is at the upstream (out-zone fault) so as to locate a fault section.
2. A peer-to-peer communication mode. Adjacent node fault signals or intercepted transient state information of a fault initial stage are interacted in real time through GOOSE communication, when a single-phase earth fault occurs at a certain point of a trunk line, fault signals judged by nodes on two sides of the fault point are opposite or transient state zero sequence current polarity is opposite, and then a fault area is judged.
For the low-voltage bus of the transformer substation, the switching station, the distribution station and the bus in the ring main unit are as follows: a terminal device can be used for centralized processing of single-phase earth faults, including bus faults or faults on an incoming line and an outgoing line.
The above embodiments do not limit the present invention in any way, and all technical solutions obtained by taking equivalent substitutions or equivalent changes fall within the scope of the present invention.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810932003.7A CN109061385B (en) | 2018-08-16 | 2018-08-16 | Single-phase ground fault detection and location isolation method based on transient steady state information |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810932003.7A CN109061385B (en) | 2018-08-16 | 2018-08-16 | Single-phase ground fault detection and location isolation method based on transient steady state information |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109061385A CN109061385A (en) | 2018-12-21 |
| CN109061385B true CN109061385B (en) | 2021-06-04 |
Family
ID=64686931
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810932003.7A Active CN109061385B (en) | 2018-08-16 | 2018-08-16 | Single-phase ground fault detection and location isolation method based on transient steady state information |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109061385B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110865278B (en) * | 2019-12-05 | 2022-07-29 | 南京四方亿能电力自动化有限公司 | Ground fault positioning method based on transient mutation energy capturing method |
| CN111289839B (en) * | 2020-03-11 | 2022-09-09 | 国网河北省电力有限公司电力科学研究院 | A method for locating single-phase grounding fault section in distribution network |
| CN111366815B (en) * | 2020-04-24 | 2022-09-20 | 北京东土科技股份有限公司 | Method, device and medium for small current grounding line selection based on distribution station server |
| CN113341272A (en) * | 2021-06-01 | 2021-09-03 | 陕西理工大学 | Transient quantity-based power distribution network single-phase earth fault section positioning system and method |
| CN113884816B (en) * | 2021-10-25 | 2024-11-29 | 北京东土科技股份有限公司 | Single-phase grounding fault section positioning method, device, equipment and storage medium |
| CN118938070A (en) * | 2024-07-26 | 2024-11-12 | 东方电子股份有限公司 | A method for capturing characteristic points of small current grounding fault |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI102700B (en) * | 1995-08-23 | 1999-01-29 | Abb Research Ltd | Procedure for locating a single-phase grounding in an electricity distribution network |
| CN102944817B (en) * | 2012-12-10 | 2015-01-07 | 国家电网公司 | Locating method and device for one-phase earth fault of power distribution network based on transient state signal wavelet transformation |
| CN105553422B (en) * | 2015-12-31 | 2017-08-01 | 西安交通大学 | A photovoltaic system arc fault detection method combined with multiple detection signals |
| CN106124936B (en) * | 2016-07-29 | 2018-09-28 | 国电南瑞科技股份有限公司 | A kind of Distributed power net method for locating single-phase ground fault |
| CN107037280B (en) * | 2016-11-11 | 2019-07-23 | 中国南方电网有限责任公司 | Protection big data fault signature system construction method based on recording scanning technique |
| CN107222280A (en) * | 2017-05-24 | 2017-09-29 | 云南电力试验研究院(集团)有限公司 | A kind of method that time synchronized is realized to different time scales fault recording system |
-
2018
- 2018-08-16 CN CN201810932003.7A patent/CN109061385B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109061385A (en) | 2018-12-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109061385B (en) | Single-phase ground fault detection and location isolation method based on transient steady state information | |
| Jahn et al. | Survey of methods for selective DC fault detection in MTDC grids | |
| Jovcic et al. | Feasibility of DC transmission networks | |
| CN105119255B (en) | Photovoltaic microgrid fault isolation method based on fault state | |
| Eladl et al. | IoT technology-based protection scheme for MT-HVDC transmission grids with restoration algorithm using support vector machine | |
| CN109347093B (en) | Power distribution network self-healing control method combining master station with local control | |
| CN109494696B (en) | Asymmetric fault location and isolation method and system for distribution network based on adaptive reclosing | |
| Johannesson et al. | Selective wave-front based protection algorithm for MTDC systems | |
| CN108957243A (en) | A kind of method for locating single-phase ground fault and system applied to power distribution network | |
| CN113884816B (en) | Single-phase grounding fault section positioning method, device, equipment and storage medium | |
| CN114089109B (en) | Method for positioning single-phase ground fault section of in-situ distribution network | |
| Marvik et al. | Communication-less fault detection in radial multi-terminal offshore HVDC grids | |
| CN110808576B (en) | Intelligent distributed single-phase earth fault isolation method suitable for small-current grounding system | |
| CN119050968A (en) | On-site distributed area protection self-healing method and system for medium-voltage distribution network | |
| CN110768206B (en) | Single-phase earth fault protection method for small-resistance earth system | |
| Mitra et al. | First real-time implementation of DC grid protection strategy | |
| CN106291229A (en) | A kind of power distribution network earthing wire-selecting method based on Distributed power termination | |
| CN204156517U (en) | A kind of intelligent substation low-voltage bus bar protection system | |
| CN111146773A (en) | Single-phase earth fault self-healing method for small current grounding system | |
| Perez-Molina et al. | A comparison of non-unit and unit protection algorithms for HVDC grids | |
| CN107230970A (en) | A kind of singlephase earth fault processing method of the feeder automation of type on the spot | |
| US11728638B2 (en) | Normally open tie pulse testing | |
| CN204651919U (en) | A kind of 10kV neutral point of electric network joint grounding device | |
| CN107516877B (en) | Small resistance grounding system failure protecting device, system and method | |
| CN110048383B (en) | Distribution network distributed comprehensive protection system |
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 |