CN111141991B - Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid - Google Patents
Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid Download PDFInfo
- Publication number
- CN111141991B CN111141991B CN201811305926.6A CN201811305926A CN111141991B CN 111141991 B CN111141991 B CN 111141991B CN 201811305926 A CN201811305926 A CN 201811305926A CN 111141991 B CN111141991 B CN 111141991B
- Authority
- CN
- China
- Prior art keywords
- power grid
- phase
- asymmetric
- voltage
- grounding
- 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
Abstract
A method suitable for improving the high-resistance grounding fault handling capacity of an asymmetric power grid is used for detecting the neutral point displacement voltage U of the power distribution grid in real time when the power distribution grid operatesNAnd three phase voltage, if distribution network neutral point voltage UNAnd if the phase voltage amplitude is larger than a certain value, the phase to ground capacitance is input at the phase with higher phase voltage amplitude to reduce the asymmetry, so that the processing capacity of the ground fault processing device on the high-resistance ground fault of the asymmetric power grid is improved.
Description
Technical Field
The invention belongs to the field of single-phase earth fault processing of a power distribution network, and is mainly used for improving the identification and processing capacity of an asymmetric power grid high-resistance earth fault.
Background
Because the parameters of the power grid to the earth are different, the asymmetry of the power grid is different, the displacement voltage of the neutral point of the power grid is different, the neutral point is not grounded, and the asymmetry coefficient K is differentCThe maximum value of (d) is: 5 percent. The running and the test show that: the identification of the asymmetry of the asymmetric electrical network to the high resistance ground of the ground fault handling device is directly related to the handling capacity. Generally, the larger the asymmetry of the power grid, the lower the identification and processing capability of the high-resistance ground of the ground fault processing device.
In an asymmetric power grid, asymmetric current is generated in a feeder line when the power grid normally operates under the action of asymmetric voltage, and the distribution of the asymmetric current in each feeder line is different due to different asymmetric parameters of each feeder line, so that great difficulty is caused in identifying and processing a high-resistance grounding fault, and a fault line cannot be selected.
The identification and processing capability of the high-resistance grounding of the grounding fault processing device has great influence on personal safety and power grid safety. Therefore, a method must be found for solving the fault identification and processing capability of the asymmetric power grid in the high-resistance earth fault so as to realize quick fault isolation to ensure personal safety and power grid safety.
Disclosure of Invention
Three-phase-to-ground switch QF is connected beside ground fault processing devicea、QFb、QFcAnd three-phase to ground capacitance Ca0、Cb0、Cc0. When the single-phase earth fault processing device is connected to a power grid, firstly, the displacement voltage U of a neutral point of the power distribution network is measuredNThree phase voltage Ua、Ub、UcWhen the displacement voltage U of the neutral point of the power grid is detectedNWhen the voltage is higher, the earth switch with the phase with the highest amplitude of the phase voltage is closed, the earth capacitor is put into the earth switch, the three-phase voltage is leveled by changing the capacitance of the capacitor, the asymmetry degree of the power grid is reduced, and the neutral point displacement voltage U of the power grid is changedNThe single-phase earth fault processing device is adjusted to a relatively small value, and the capacity of identifying and processing the high-resistance earth fault of the asymmetric power grid by the single-phase earth fault processing device is improved.
When the single-phase grounding fault processing device is a grounding line selection device, a grounding capacitor is put into a phase with high phase voltage amplitude, the asymmetry degree of a power grid is reduced, the influence of asymmetric zero-sequence current generated in a feeder line due to the asymmetry of the power grid on the grounding line selection is reduced, and the high-resistance line selection capability of the grounding line selection device on the asymmetric power grid is improved.
Three phase to ground capacitance Ca0、Cb0、Cc0The capacitance of the capacitor can be automatically adjusted by adopting an adjustable capacitor, and can also be manually adjusted according to the actual power grid.
The invention has the following advantages:
1. according to the invention, the ground capacitance is put into the phase with the highest phase voltage amplitude, so that the identification and processing capacity of the ground fault processing device on the high-resistance ground fault of the asymmetric power grid is improved, and the method is simple and easy to implement. .
2. The invention reduces the influence of the differential distribution of the asymmetric zero sequence current generated in the feeder line due to the asymmetry of the power grid on the grounding line selection, and effectively improves the high-resistance line selection capability of the grounding line selection device in the asymmetric power grid.
Drawings
FIG. 1 is a schematic diagram of the device, QFa、QFb、QFcIs a relative ground switch; ca0、Cb0、Cc0Is a relative capacitance to ground.
Detailed Description
Three-phase-to-ground switch QF is connected beside ground fault processing devicea、QFb、QFcAnd three-phase to ground capacitance Ca0、Cb0、Cc0. When the single-phase earth fault processing device is connected to a power grid, firstly, the displacement voltage U of a neutral point of the power distribution network is measuredNThree phase voltage Ua、Ub、UcWhen the displacement voltage U of the neutral point of the power grid is detectedNWhen the voltage is higher, the earth switch with the phase with the highest amplitude of the phase voltage is closed, the earth capacitor is put into the earth switch, the three-phase voltage is leveled by changing the capacitance of the capacitor, the asymmetry degree of the power grid is reduced, and the neutral point displacement voltage U of the power grid is changedNThe single-phase earth fault processing device is adjusted to a relatively small value, and the capacity of identifying and processing the high-resistance earth fault of the asymmetric power grid by the single-phase earth fault processing device is improved.
When the single-phase grounding fault processing device is a grounding line selection device, a grounding capacitor is put into a phase with high phase voltage amplitude, the asymmetry degree of a power grid is reduced, the influence of asymmetric zero-sequence current generated in a feeder line due to the asymmetry of the power grid on the grounding line selection is reduced, and the high-resistance line selection capability of the grounding line selection device on the asymmetric power grid is improved.
Three phase to ground capacitance Ca0、Cb0、Cc0The capacitance of the capacitor can be automatically adjusted by adopting an adjustable capacitor, and can also be manually adjusted according to the actual power grid.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that several modifications and adaptations to those skilled in the art without departing from the principles of the present invention should also be considered within the scope of the present invention.
Claims (3)
1. A method for improving the high-resistance grounding fault handling capability of an asymmetric power grid is characterized in that a relative ground switch QF is adopteda、QFb、QFcAnd three-phase to ground capacitance Ca0、Cb0、Cc0The structure is characterized in that: when the single-phase earth fault processing device is connected to a power grid, firstly, the displacement voltage U of a neutral point of the power distribution network is measuredNThree phase voltage Ua、Ub、UcWhen the displacement voltage U of the neutral point of the power grid is detectedNWhen the voltage is higher, the earth switch with the phase with the highest amplitude of the phase voltage is closed, the earth capacitor is put into the earth switch, the three-phase voltage is leveled by changing the capacitance of the capacitor, the asymmetry degree of the power grid is reduced, and the neutral point displacement voltage U of the power grid is changedNThe single-phase earth fault processing device is adjusted to a relatively small value, and the capacity of identifying and processing the high-resistance earth fault of the asymmetric power grid by the single-phase earth fault processing device is improved.
2. The method for improving the high resistance earth fault handling capacity of the asymmetric power grid according to claim 1, wherein the method comprises the following steps: when the single-phase grounding fault processing device is a grounding line selection device, a grounding capacitor is put into a phase with high phase voltage amplitude, the asymmetry degree of a power grid is reduced, the influence of asymmetric zero-sequence current generated in a feeder line due to the asymmetry of the power grid on the grounding line selection is reduced, and the high-resistance line selection capability of the grounding line selection device on the asymmetric power grid is improved.
3. The method for improving the high resistance earth fault handling capacity of the asymmetric power grid according to claim 1, wherein the method comprises the following steps: three phase to ground capacitance Ca0、Cb0、Cc0The capacitance of the capacitor can be automatically adjusted by adopting an adjustable capacitor, and can also be manually adjusted according to the actual power grid.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811305926.6A CN111141991B (en) | 2018-11-05 | 2018-11-05 | Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811305926.6A CN111141991B (en) | 2018-11-05 | 2018-11-05 | Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111141991A CN111141991A (en) | 2020-05-12 |
CN111141991B true CN111141991B (en) | 2021-12-24 |
Family
ID=70515564
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201811305926.6A Active CN111141991B (en) | 2018-11-05 | 2018-11-05 | Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111141991B (en) |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102798795A (en) * | 2012-08-14 | 2012-11-28 | 大连电力勘察设计院有限公司 | Method capable of realizing low-current route selection and fault location |
CN103545796A (en) * | 2013-09-16 | 2014-01-29 | 国家电网公司 | Single-phase grounding fault handling device and method for power distribution network with non-effectively grounded neutral points |
CN103887805A (en) * | 2014-01-07 | 2014-06-25 | 中国石油大学(华东) | Asymmetric voltage control method of small current grounding system |
CN104880647A (en) * | 2015-06-15 | 2015-09-02 | 中国矿业大学 | Earth fault phase identification method based on injection method |
CN105119257A (en) * | 2015-07-25 | 2015-12-02 | 李景禄 | Dynamic processing method for single-phase transition resistor grounding fault of power distribution network |
CN106771648A (en) * | 2016-12-30 | 2017-05-31 | 国网天津市电力公司 | A kind of capacitance current of distribution network measuring method based on improvement signal injection method |
CN107508296A (en) * | 2017-07-26 | 2017-12-22 | 国网山东省电力公司莱芜供电公司 | A kind of system and method for the regulating time for reducing control asymmetrical voltage |
CN108287296A (en) * | 2018-02-07 | 2018-07-17 | 李景禄 | One kind being suitable for unbalance grid high resistance earthing fault reverse starting and route selection method |
CN208046228U (en) * | 2018-03-23 | 2018-11-02 | 大连依诺维电气有限公司 | Neutral point variable resistance earthed system |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1992954B1 (en) * | 2007-05-18 | 2017-12-13 | ABB Schweiz AG | Method for determining location of phase-to-earth fault |
-
2018
- 2018-11-05 CN CN201811305926.6A patent/CN111141991B/en active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102798795A (en) * | 2012-08-14 | 2012-11-28 | 大连电力勘察设计院有限公司 | Method capable of realizing low-current route selection and fault location |
CN103545796A (en) * | 2013-09-16 | 2014-01-29 | 国家电网公司 | Single-phase grounding fault handling device and method for power distribution network with non-effectively grounded neutral points |
CN103887805A (en) * | 2014-01-07 | 2014-06-25 | 中国石油大学(华东) | Asymmetric voltage control method of small current grounding system |
CN104880647A (en) * | 2015-06-15 | 2015-09-02 | 中国矿业大学 | Earth fault phase identification method based on injection method |
CN105119257A (en) * | 2015-07-25 | 2015-12-02 | 李景禄 | Dynamic processing method for single-phase transition resistor grounding fault of power distribution network |
CN106771648A (en) * | 2016-12-30 | 2017-05-31 | 国网天津市电力公司 | A kind of capacitance current of distribution network measuring method based on improvement signal injection method |
CN107508296A (en) * | 2017-07-26 | 2017-12-22 | 国网山东省电力公司莱芜供电公司 | A kind of system and method for the regulating time for reducing control asymmetrical voltage |
CN108287296A (en) * | 2018-02-07 | 2018-07-17 | 李景禄 | One kind being suitable for unbalance grid high resistance earthing fault reverse starting and route selection method |
CN208046228U (en) * | 2018-03-23 | 2018-11-02 | 大连依诺维电气有限公司 | Neutral point variable resistance earthed system |
Non-Patent Citations (3)
Title |
---|
Measuring phase-to-ground capacitance based on displacement voltage method;Jie Zhou;《Preprints of the 5th international conference on Electric Utility Deregulation and Restructuring and Power Technologies》;20151231;全文 * |
补偿电网中性点位移电压异常的原因及对策;汤放奇;《高电压技术》;20050430;全文 * |
适用于高阻接地故障的谐振接地系统故障选线技术研究;王怡轩;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20170115;全文 * |
Also Published As
Publication number | Publication date |
---|---|
CN111141991A (en) | 2020-05-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Zhang et al. | Fault analysis and traveling-wave protection scheme for bipolar HVDC lines | |
Makwana et al. | A new digital distance relaying scheme for compensation of high-resistance faults on transmission line | |
Parikh et al. | Fault classification technique for series compensated transmission line using support vector machine | |
Jafarian et al. | High-speed superimposed-based protection of series-compensated transmission lines | |
US11435409B2 (en) | Temporary overvoltage and ground fault overvoltage protection based on arrester current measurement and analysis | |
CN103840437B (en) | The quick diagnosis of power distribution network ferromagnetic resonance and singlephase earth fault and processing method | |
CN103872667B (en) | A kind of Line Current Differential Protection method of the abnormal big number of anti-combining unit | |
CN108318762B (en) | Method for judging power frequency ferromagnetic resonance of voltage transformer | |
CN104269256B (en) | Voltage transformer disappears the method for the automatic tracking adjustment of humorous resistance | |
CN104820169A (en) | Single-phase ground fault positioning method for neutral grounding system via arc suppression coil | |
Fan et al. | Faulty phase recognition method based on phase-to-ground voltages variation for neutral ungrounded distribution networks | |
Sahebi et al. | Evaluation of power transformer inrush currents and internal faults discrimination methods in presence of fault current limiter | |
Torres | High impedance fault detection using discrete wavelet transform | |
Ying et al. | Travelling wave‐based pilot direction comparison protection for HVDC line | |
Kavi et al. | Detection and identification of high impedance faults in single wire earth return distribution networks | |
Garcia et al. | High impedance fault detection in Distribution System using Wavelet Transform | |
CN111141991B (en) | Method suitable for improving high-resistance grounding fault handling capacity of asymmetric power grid | |
Mohseni et al. | Sensitivity analysis and stochastic approach in study of transient recovery voltage with presence of superconducting FCL | |
Chen et al. | Location for single‐phase grounding fault in distribution network based on equivalent admittance distortion rate | |
CN108254650B (en) | Quick judgment method for single-phase earth fault of substation bus | |
Wang et al. | A survey on faulty line selection technology for single-phase-to-ground fault in China | |
Balcerek et al. | Centralized substation level protection for determination of faulty feeder in distribution network | |
WO2003023425A1 (en) | Crossover fault classification for power lines with parallel circuits | |
Shah et al. | Detection and classification of high impedance faults in transmission line using alienation-based analysis on voltage signals | |
CN104967107B (en) | A kind of method for inhibiting intermittent arc grounding overvoltage |
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 |