CN106908693B - Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy - Google Patents
Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy Download PDFInfo
- Publication number
- CN106908693B CN106908693B CN201710127298.6A CN201710127298A CN106908693B CN 106908693 B CN106908693 B CN 106908693B CN 201710127298 A CN201710127298 A CN 201710127298A CN 106908693 B CN106908693 B CN 106908693B
- Authority
- CN
- China
- Prior art keywords
- transformer
- grounding
- phase
- sequence current
- zero
- 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
-
- 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
Abstract
The invention discloses a single-phase grounding line selection method of an arc suppression coil grounding system with high accuracy, wherein a series circuit formed by a grounding resistor and a circuit breaker is connected in parallel at two ends of the arc suppression coil, and the circuit breaker is in a closing state during normal operation; the zero sequence current transformer is additionally arranged on each outlet line of a bus of the transformer station without the zero sequence current transformer; when the single-phase is grounded, the existing microcomputer protection device of the transformer substation is utilized to collect the zero sequence current of the zero sequence current transformer, and when the zero sequence current flowing through the transformer is larger than a setting value I zd0 When the fault line is determined, a fault signal is sent after the setting time T1; when the zero sequence voltage of the busbar voltage transformer rises to a certain value U zd0 And judging that the single phase is grounded, and tripping the circuit breaker connected with the grounding resistor in series through an outlet after time T2. The advantages are that: the transformation is simple, the line selection accuracy is greatly improved under the condition that the safe and stable operation of the system is not influenced, the economic loss caused by line selection errors is reduced, and the continuous power supply to the power users is ensured.
Description
Technical Field
The invention relates to a single-phase grounding line selection method of an arc suppression coil grounding system with high accuracy.
Background
In China, most of the 6-35 kV medium-voltage distribution network systems adopt a mode that neutral points are not directly grounded, and the neutral points are called as small-current grounding systems. The probability of single-phase earth faults in the distribution network accounts for about 80% of the total faults. In a low-current grounding system, single-phase grounding has little threat to the power grid, and can continue to operate for 1-2 hours. The neutral point connection mode of the power distribution network system in China comprises the following steps: the neutral point is not grounded, the neutral point is grounded through a small resistor, and the neutral point is grounded through an arc suppression coil. Along with the development of power grid construction, the power transmission line of the power distribution network is longer, and the cable application is more and more, so that the capacitance to ground of the line is increased. If only a neutral point ungrounded mode is adopted, the increase of short-circuit current of the fault point is unfavorable for arc extinction and forms a greater threat to equipment insulation. The arc suppression coil grounding system can effectively reduce the grounding current of a fault point, but also weakens the sensitivity and the selectivity of selecting a fault line device by utilizing the information quantity, and influences the reliability of power supply. The small-resistance grounding system can accurately and rapidly cut off a single-phase grounding fault line, but reduces the power supply reliability.
At present, after a single-phase earth fault of the power distribution network, pull Lu Fa is generally adopted, and a regulator performs test pull on each outgoing line of the bus line one by one according to the running experience and the parameters of the length, the existence of important load and the like of the line. The method has low line selection accuracy, expands the power failure range, and needs to make corresponding work order treatment according to the power failure range, thereby reducing the power supply reliability, increasing the number of work orders and even causing unnecessary complaints. Therefore, when a single-phase grounding occurs in the system, a fault line is rapidly and accurately determined, the fault of the line is accelerated, the operation reliability is improved, the comprehensive economic loss caused by power failure is reduced, and the continuous power supply to the power user is ensured, so that the system has an important effect. At present, the grounding line selection device in the market mostly adopts a small signal analysis method for a fault line, is greatly disturbed by a system, and particularly for an arc suppression coil grounding system, the grounding current of the fault line is less obvious, and the accuracy is not high.
Disclosure of Invention
The invention aims to provide a single-phase grounding route selection method of an arc suppression coil grounding system with high accuracy, which can effectively solve the problem of low route selection accuracy of the current arc suppression coil grounding system.
In order to solve the technical problems, the invention is realized by the following technical scheme: a high-accuracy arc suppression coil grounding system single-phase grounding route selection method comprises the following steps:
A. the two ends of the arc suppression coil are connected in parallel with a series circuit formed by a grounding resistor and a circuit breaker, and the circuit breaker is in a closing state during normal operation;
B. the zero sequence current transformer is additionally arranged on each outlet line of a bus of the transformer station without the zero sequence current transformer;
C. acquisition by using existing microcomputer protection device of transformer substationThe zero-sequence current of the zero-sequence current transformer is added with zero-sequence current protection, the protection is only used for signaling and is not exported, when the single phase is grounded, the zero-sequence current flowing through the fault line is increased, and when the zero-sequence current flowing through the fault line is larger than the setting value I zd0 When the fault line is determined, a fault signal is sent after the setting time T1;
D. the method comprises the steps of collecting zero sequence voltage of bus voltage transformer by using the existing microcomputer protection device of a transformer substation, raising the zero sequence voltage when the single phase is grounded, and judging that the single phase is grounded U when the zero sequence voltage is raised to a certain value zd0 And after a time T2 the outlet trips the circuit breaker in step a.
Preferably, the time T1 in step C is less than the time T2 in step D.
Preferably, the selection of the grounding resistance R in the step a should satisfy:
wherein U is N0 Is the neutral point voltage when the single-phase is grounded,
according to different conditions of short-time operation, the value of k is different, S e For the ground-to-rated capacity, the ground-to-short capacity +.>
I 0 Is a single-phase grounding neutral point current which flows through the grounding Lmin The minimum gear current of the arc suppression coil.
Compared with the prior art, the invention has the advantages that: under the normal operation mode, the grounding resistance connected with the two ends of the arc suppression coil in parallel increases the damping rate of the power grid, reduces the neutral point voltage of the arc suppression coil grounding system, and meets the normal operation requirement. When the single-phase grounding is carried out, the zero-sequence active component of the grounding current is increased, the zero-sequence current flowing on a fault line is increased, the sensitivity of the microcomputer protection device is improved, and the accuracy of line selection is improved. As long as the resistance value and the zero sequence protection setting value of the grounding resistor are reasonably set, the theoretical accuracy can reach 100 percent. When two-phase grounding short circuit and three-phase grounding short circuit exist, the grounding resistance is equivalent to a path which is connected with a zero sequence active component in parallel, so that fault current is increased during fault, and the sensitivity of the relay protection device is improved. When two-phase non-grounding short circuit and three-phase non-grounding short circuit, zero sequence component is not generated, so that the existence of grounding resistance has no influence on the two faults. When single-phase earth faults occur on each outgoing line, the zero-sequence current of the fault line protects fault signals sent by the power regulator, after informing the distribution network repair center of power failure information and work order programming, the fault line is pulled open in time under the condition that the earth resistance is not disconnected by the circuit breaker, the earth signals disappear, and the earth resistance is continuously connected into the system to operate; when a single-phase earth fault occurs on the bus, the zero-sequence current protection of each outgoing line will not send out fault signals, and the earth resistor will be disconnected by the circuit breaker after the setting time and then is taken out of operation.
On the basis of the existing transformer substation, the transformation is simple, the line selection accuracy is greatly improved under the condition that the safe and stable operation of the system is not affected, the economic loss caused by line selection errors is reduced, and the continuous power supply to the power users is ensured.
Drawings
FIG. 1 is a wiring diagram of an embodiment of the present invention as applied to a substation;
fig. 2 is a short-time capacity and rated capacity conversion table listed according to the IEEE C62.92.3 standard;
FIG. 3 shows the grounding resistance current I when a certain outgoing line is grounded R And arc suppression coil current I L A waveform;
FIG. 4 shows the neutral point current I when a certain outgoing line is grounded 0 And fault line zero sequence current I L0 A waveform;
fig. 5 is the voltage at which the ground becomes neutral when the ground resistor is operated and disconnected after the ground has occurred.
Detailed Description
The embodiment of the invention relates to a single-phase grounding line selection method of an arc suppression coil grounding system with high accuracy, which is based on a 110kV transformer substation, according to a wiring diagram of FIG. 1, and comprises the following steps:
A. the two ends of the arc suppression coil are connected in parallel with a series circuit formed by a grounding resistor and a circuit breaker, and the circuit breaker is in a closing state during normal operation;
B. zero sequence current transformers are additionally arranged on outgoing lines of a 10kV bus of the transformer substation, and the existing zero sequence current transformers are not required to be additionally arranged on lines;
C. the zero sequence current of the zero sequence current transformer is collected by the existing microcomputer protection device of the transformer substation, and the zero sequence current protection is put into the transformer substation, and the protection is only transmitted and not outputted. When the single phase is grounded, the zero sequence current flowing through the fault line increases, and when the zero sequence current is greater than the setting value I zd0 When the signal is=40a (primary side), a fault signal is sent out after the setting time t1=1s, and a fault line is determined;
D. the microcomputer protection device collects the zero sequence voltage of the 10kV bus voltage transformer, when the single phase is grounded, the zero sequence voltage rises, and when the zero sequence voltage rises to a certain value U zd0 when=60V, it is determined that the single phase is grounded, and the circuit breaker in the outlet trip 1 is tripped after time t2=10 minutes.
The grounding resistance should meet the requirements of zero sequence current protection sensitivity and grounding variable short-circuit capacity. The specific calculation method is as follows:
A. meets the requirement of zero sequence current protection sensitivity
When single-phase grounding, approximate neutral point voltage U N0 Equal to the phase voltage, i.e. 6kV. Then there is
B. Meet the requirement of the capacity of the grounding short circuit
The grounding transformer type adopted by the transformer substation is DKSC-630/80/10.5, and the rated capacity is 630kVA. If the ground resistance is allowed to continue to operate for 2 hours under the condition of grounding, k is 1.4 as can be seen from the short-time capacity and rated capacity conversion table in fig. 2. The type of the arc suppression coil of the transformer substation is XHDCZ-500/10.5, and the current is 20A in the lowest gear, so the transformer substation has
In order to avoid that the zero sequence active current is too small due to the fact that the neutral point voltage is too low when the grounding is not completely conducted, the zero sequence current setting value cannot be achieved, the grounding resistance R is as small as possible, and R=60deg.C is taken.
As shown in fig. 3, the current I of the grounding resistor is the same as the single-phase grounding of a certain outgoing line R And arc suppression coil current I L When a single-phase earth fault occurs at the time t1, the waveform compensates the system capacitance current by the inductive current flowing in the arc suppression coil, and the zero-sequence active current flows in the resistor so as to improve the sensitivity of zero-sequence current protection.
As shown in fig. 4, the neutral point current I becomes when a certain outgoing line is grounded in a single phase 0 And fault line zero sequence current I L0 The waveform at time t1 is in single-phase earth fault, the zero-sequence current of the fault line is increased to 56.6A due to the existence of the earth resistance, the requirement of zero-sequence current protection sensitivity is met, and as can be seen from fig. 3, the earth neutral point current is about 60.1A, the short-time capacity is 363.7kVA, and the earth variable-length running condition is met. the fault line is pulled apart at the time t2, and the ground becomes neutral point current I 0 And fault line zero sequence current I L0 And the normal operation level is restored.
As shown in fig. 5, the voltage of the ground becomes neutral point when the ground resistor is operated and disconnected after the ground occurs, the single-phase ground occurs at time t1, the ground resistor is operated, the ground resistor is withdrawn from operation at time t2, and as can be seen from the figure, after the ground occurs, the neutral point voltage is obviously lower than that when the ground resistor is withdrawn from operation, so that the voltage level of the neutral point can be reduced by connecting the ground resistors at both ends of the arc suppression coil in parallel.
According to the embodiment, the invention is simple to modify on the basis of the existing transformer substation, greatly improves the line selection accuracy, reduces the economic loss caused by line selection errors and ensures continuous power supply to power users under the condition that the safe and stable operation of the system is not affected.
The above embodiments are merely illustrative embodiments of the present invention, but the technical features of the present invention are not limited thereto, and any changes or modifications made by those skilled in the art within the scope of the present invention are included in the scope of the present invention.
Claims (2)
1. A single-phase grounding route selection method of an arc suppression coil grounding system with high accuracy is characterized by comprising the following steps: the method comprises the following steps:
A. the two ends of the arc suppression coil are connected in parallel with a series circuit formed by a grounding resistor and a circuit breaker, and the circuit breaker is in a closing state during normal operation;
the selection condition of the grounding resistor R is as follows:
wherein U is N0 Is the neutral point voltage when the single-phase is grounded,
according to different conditions of short-time operation, the value of k is different, S e For the ground-to-rated capacity, the ground-to-short capacity +.>
I 0 When the current is single-phase earth, the current flows through the earth to become neutral point,
I Lmin minimum gear current for arc suppression coil;
B. the zero sequence current transformer is additionally arranged on each outlet line of a bus of the transformer station without the zero sequence current transformer;
C. the zero-sequence current of the zero-sequence current transformer is collected by the existing microcomputer protection device of the transformer substation, and the zero-sequence current protection is put into the transformer, the protection is only to send out no output, when the transformer is in single-phase grounding, the zero-sequence current flowing through a fault line is increased, and when the zero-sequence current flowing through the transformer is larger than a setting value I zd0 When the fault line is determined, a fault signal is sent after the setting time T1;
D. the zero sequence voltage of the busbar voltage transformer is collected by the existing microcomputer protection device of the transformer substation, and when the single phase is grounded,
the zero sequence voltage rises, when the zero sequence voltage rises to a certain value U zd0 And judging that the single phase is grounded, and opening the circuit breaker in the step A after the time T2.
2. The high-accuracy arc suppression coil grounding system single-phase grounding line selection method as claimed in claim 1, wherein the method comprises the following steps: time T1 in step C is less than time T2 in step D.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710127298.6A CN106908693B (en) | 2017-03-06 | 2017-03-06 | Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710127298.6A CN106908693B (en) | 2017-03-06 | 2017-03-06 | Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106908693A CN106908693A (en) | 2017-06-30 |
| CN106908693B true CN106908693B (en) | 2023-07-07 |
Family
ID=59186805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710127298.6A Active CN106908693B (en) | 2017-03-06 | 2017-03-06 | Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106908693B (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107843809A (en) * | 2017-10-30 | 2018-03-27 | 国网湖南省电力公司 | The earthing wire-selecting method differentiated based on zero sequence |
| CN108321784B (en) * | 2018-01-15 | 2019-07-30 | 中国矿业大学 | A kind of neutral ground method based on arc suppression coil and constant watt current |
| CN108306276A (en) * | 2018-02-02 | 2018-07-20 | 梅素真 | A kind of arc suppression coil capacity-increasing transformation method of power distribution network and apply its power distribution network |
| CN108279360A (en) * | 2018-03-29 | 2018-07-13 | 山东钢铁股份有限公司 | Singlephase earth fault circuit monitoring system |
| CN108258668A (en) * | 2018-03-30 | 2018-07-06 | 九江电力勘察设计院有限公司 | Disturbance DC component line selection apparatus based on silicon-controlled generation during single-phase earthing |
| CN109004531A (en) * | 2018-07-27 | 2018-12-14 | 国网江苏省电力有限公司苏州供电分公司 | A kind of neutral resistance complexes |
| CN109541383B (en) * | 2019-02-13 | 2021-02-02 | 云南电网有限责任公司电力科学研究院 | Method and device for positioning and protecting ground fault based on controllable voltage source |
| CN109672164B (en) * | 2019-02-22 | 2020-01-21 | 国网湖北省电力有限公司电力科学研究院 | Method for processing ground fault of arc suppression coil parallel small-resistance power distribution network |
| CN110146783B (en) * | 2019-05-15 | 2021-09-21 | 上海宏力达信息技术股份有限公司 | Fault section positioning method |
| CN110416990A (en) * | 2019-06-17 | 2019-11-05 | 赵子云 | Medium voltage network neutral ground controls equipment |
| CN110212511B (en) * | 2019-06-28 | 2021-03-12 | 中国能源建设集团辽宁电力勘测设计院有限公司 | 66kV arc suppression coil grounding system based on resistance remote automatic switching |
| CN110445115A (en) * | 2019-07-03 | 2019-11-12 | 中山职业技术学院 | A kind of more arc suppression coil auto parallel Connection fuzzy control methods |
| CN110888083A (en) * | 2019-10-12 | 2020-03-17 | 国网山东省电力公司莱芜供电公司 | Arc suppression coil ground fault positioning method based on transformer substation line protection device, transformer substation and readable storage medium |
| CN110568316A (en) * | 2019-10-16 | 2019-12-13 | 国网四川省电力公司绵阳供电公司 | Method for quickly selecting line of ground fault of low-current grounding system |
| CN112666421A (en) * | 2019-10-16 | 2021-04-16 | 李景禄 | Fault area isolation method based on compensation damping type active intervention arc suppression device |
| CN111781462A (en) * | 2020-06-23 | 2020-10-16 | 国网山东省电力公司聊城供电公司 | Power distribution network single-phase earth fault line selection method, system, medium and equipment |
| CN112067948B (en) * | 2020-10-14 | 2022-03-11 | 长沙理工大学 | Fault line selection method and system for single-phase earth fault of power distribution network |
| CN112595925B (en) * | 2020-12-01 | 2023-01-31 | 国网山东省电力公司青岛供电公司 | 10kV distribution network ground fault process processing method and system |
| CN112886553A (en) * | 2021-02-03 | 2021-06-01 | 国网安徽省电力有限公司电力科学研究院 | Out-station grounding configuration method for single-phase protection of low-current grounding system |
| CN113156251B (en) * | 2021-04-26 | 2024-03-29 | 珠海菲森电力科技有限公司 | Ground fault simulation experiment table for non-effective grounding system |
| CN113917362A (en) * | 2021-09-28 | 2022-01-11 | 国电南瑞科技股份有限公司 | Single-phase earth fault positioning method, system and storage medium |
| CN114113914B (en) * | 2021-12-08 | 2023-08-22 | 国网湖南省电力有限公司 | Power distribution network single-phase earth fault detection method based on zero sequence impedance comparison |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1309137C (en) * | 2003-07-24 | 2007-04-04 | 上海交通大学 | Method for earthing and line selecting by using compensating electrified wire netting increment function |
| EP2530804A1 (en) * | 2011-06-01 | 2012-12-05 | ABB Research Ltd. | Improved ground fault handling in power distribution systems with mixed underground and aerial power lines |
| CN104865498B (en) * | 2015-05-07 | 2017-08-29 | 燕山大学 | Arc suppression coil earthing system single-phase ground fault distance measuring method based on parameter identification |
-
2017
- 2017-03-06 CN CN201710127298.6A patent/CN106908693B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN106908693A (en) | 2017-06-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106908693B (en) | Single-phase grounding route selection method of arc suppression coil grounding system with high accuracy | |
| CN101304170B (en) | System debug method for high voltage direct current transmission project | |
| CN110011285B (en) | Grounding system and method for high-voltage high-capacity flexible direct current engineering | |
| CN110768206B (en) | Single-phase earth fault protection method for small-resistance earth system | |
| CN105356441A (en) | Intelligent PT harmonic elimination and phase selection method and device | |
| CN100387999C (en) | Circuit fault directional detecting and protecting method for power supply system | |
| CN103595022B (en) | The relay protection and control method of 500kV electric substations 35kV house transformer current-limiting reactors | |
| CN202586308U (en) | Comprehensive grounding protective device for microcomputer | |
| CN104065056A (en) | Process control method of 10 kV power grid ground fault | |
| CN112952775B (en) | Method for protecting voltage quantity of power distribution network containing distributed photovoltaic power supply | |
| CN112968423B (en) | Overcurrent protection method for protecting turn-to-turn short circuit fault of low-voltage winding of grounding transformer | |
| CN106501674A (en) | Medium voltage distribution network single-phase earth fault positioning device and its Fault Locating Method | |
| CN210534262U (en) | Large-current fault line selection system of resonance grounding system | |
| CN111769518A (en) | Power station transformer neutral point protection method based on gap protection and lightning arrester | |
| CN203217026U (en) | Single-phase ground fault wire selection system of small current grounding system | |
| CN111880110A (en) | Single-phase earth fault disappearance judgment method and system for neutral point non-effective earthing system | |
| AU2020220030B2 (en) | Fault protection configuration for a resettable transformer protector | |
| CN103560501A (en) | Controlled type small-resistor arc extinction device and method | |
| CN104749453A (en) | Method for reducing influences imposed on user voltage sag by external grid single-phase grounding fault | |
| CN203883464U (en) | Controllable small-resistor arc-extinguishing device | |
| CN109921405A (en) | A kind of earthing method of medium voltage network neutral point | |
| Kokor et al. | Effects of neutral point grounding methods on single-phase short circuit fault characteristics | |
| Walling | Overvoltage protection and arrester selection for large wind plants | |
| Shirkovets et al. | Schemes, Neutral Grounding Treatment and Organization of Ground Fault Relay Protection in 20 kV Networks of Megalopolises | |
| CN210534261U (en) | Large-current fault line selection 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 |