CN104779594B - Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method - Google Patents
Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method Download PDFInfo
- Publication number
- CN104779594B CN104779594B CN201510207792.4A CN201510207792A CN104779594B CN 104779594 B CN104779594 B CN 104779594B CN 201510207792 A CN201510207792 A CN 201510207792A CN 104779594 B CN104779594 B CN 104779594B
- Authority
- CN
- China
- Prior art keywords
- phase
- current
- residual voltage
- grounding
- fault
- 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
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention discloses a kind of phase fault of small current neutral grounding power system and single-phase grounding comprehensive protecting method, and first, protection device gathers three-phase current and residual voltage, and calculates the Sudden Changing Rate of each phase current and residual voltage in real time；Then whether out-of-limit detect difference of phase currents, if difference of phase currents exceedes definite value, be determined as phase fault, and enter stage current protection program；Otherwise, whether out-of-limit detect residual voltage Sudden Changing Rate, if residual voltage Sudden Changing Rate exceedes definite value, be determined as singlephase earth fault, and enter single-phase grounding selecting program；The present invention has phase fault protection and two functions of small current earthing wire-selecting concurrently, can quickly and reliably be acted when phase fault occurs in tripping operation, and and can accurate route selection and sends alarm signal in small current neutral grounding system generation single-phase earthing；During using guard method of the present invention, only a phase fault and single-phase grounding comprehensive protecting device need to be configured in each outlet head end, be not required to individually install Small Electric Current Earthing And Routing Device again, effectively simplify relaying configuration.
Description
Technical field
The invention belongs to field of power, is related to field of relay protection in power, and in particular to a kind of low current connects
Ground power system phase fault and single-phase grounding comprehensive protecting method.
Background technology
In low and medium voltage distribution network, usual each bar outlet is provided with stage current protective device, when generation phase fault
During failure, protection installation place will flow through obvious short circuit current, and device is true by the size for judging measurement electric current and setting valve
Determining failure is in area or outside area, and troubles inside the sample space is quickly cut off.
To improve Operation of Electric Systems reliability, China's low and medium voltage distribution network generally use small current neutral grounding method of operation.
Be not in obvious fault current when singlephase earth fault occurs for a certain bar circuit, now system can tape jam continuation
Operation, but faulty line must be selected as early as possible and take counter-measure.At present, it is furnished with one or more compared with multi-Substation special secondary school door
(different principle) centralized line selection apparatus, when singlephase earth fault occurs, selected by the electric measure feature for contrasting a plurality of circuit
Faulty line.But each transformer station must individually install line selection apparatus, not only increase construction cost, also cause operation maintenance more
Add complexity.
In recent years, with the appearance of the line selection algorithm with bootstrapping property, it is already possible to distributing route selection is realized, merely with this
The information of circuit can determine whether this circuit is faulty line.The it is proposed of such algorithm, to be grounded route selection and alternate short
Road protection integration provides possibility.
The content of the invention
To solve the above-mentioned problems of the prior art, it is an object of the invention to provide one kind to be used for small current neutral grounding electric power
The comprehensive method of protection of system, stage current protection is engaged with the selection method with bootstrapping property, one kind is formed and is used for
The phase fault of small current neutral grounding power system and single-phase grounding comprehensive protecting method.Use guard method of the present invention
When, only a phase fault and single-phase grounding comprehensive protecting device need to be configured in each outlet head end, be not required to individually install again
Small Electric Current Earthing And Routing Device, effectively simplify relaying configuration.
To reach above-mentioned purpose, the technical solution adopted by the present invention is：
A kind of small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method, comprise the following steps：
Step 1：Collection small current neutral grounding protecting electrical power system installation place residual voltage in real timeAnd three-phase currentLow-frequency sampling of the residual voltage using sample frequency for 1.2kHz, three-phase current are using sample frequency
25.6kHz high frequency sampling；
Step 2：Difference of phase currents is calculated, and using three-phase current Sudden Changing Rate starting algorithm judges whether to occur alternate
Short trouble, if difference of phase currents is out-of-limit, it is determined as phase fault and enters step 3, otherwise into step 4；
Step 3：By sample frequency be 25.6kHz three-phase current sampling of data into 1.2kHz low-frequency sampling data, make
Three-phase current amplitude is extracted with fourier algorithm, and judges that the failure is troubles inside the sample space or area by stage current protection program
Outer failure, then acted if troubles inside the sample space in tripping operation, otherwise device involution；
Step 4：Residual voltage Sudden Changing Rate is calculated, and judges whether residual voltage Sudden Changing Rate is out-of-limit, if residual voltage is mutated
Amount is lasting out-of-limit in 5ms time windows, then is determined as singlephase earth fault and enters step 5, otherwise device involution；
Step 5：Start the single-phase grounding selecting algorithm with bootstrapping property, use the three-phase electricity that sample frequency is 25.6kHz
High frequency sampled data is flowed, judges whether this circuit is faulty line, then sends out alarm signal if faulty line, otherwise device is answered
Return.
Preferably, three-phase current Sudden Changing Rate starting algorithm is as follows described in step 2：
In formula：Represent separate, n is current sampling point, and N is the sampling number of each power frequency period；For phase current
Current sample values,For difference of phase currents, can be tried to achieve by formula (2)；For floating threshold, can be obtained by formula (3)；
InRepresent load current amplitude；k1、k2For safety factor；
For each phase current signal, when continuous 3 jump-value of current sampled values exceed predetermined threshold level
When i.e. formula (1) is set up, then judge phase fault occurs, protection starts.
Preferably, the safety factor k1=1.25, safety factor k2=0.06.
Preferably, residual voltage Sudden Changing Rate starting algorithm is as follows described in step 4：
Δu0[n]=u0[n]-u0[n-N] (4)
In formula：N is current sampling point, and N is the sampling number of each power frequency period；u0[n] is adopting in real time for residual voltage
Sample value, Δ u0[n] is the real-time Sudden Changing Rate of residual voltage, can be tried to achieve by formula (4)；ΔU0[n] is residual voltage Sudden Changing Rate amplitude,For phase voltage amplitude, m is startup coefficient；
When formula (5) is set up, then decision-making system residual voltage is out-of-limit, and starts single-phase earthing recognizer；
Preferably, the startup coefficient m=0.2；
Preferably, in step 5, the single-phase grounding selecting algorithm with bootstrapping property can use existing adaptive seizure special
The transient state phase current line selection algorithm for levying frequency band implements route selection, and the algorithm is with bootstrapping property and with higher route selection accuracy.
Compared to the prior art compared with the present invention possesses following advantage：
The present invention proposes a kind of integrated protection scheme of phase fault and single-phase earthing, in small current neutral grounding power system
In, Small Electric Current Earthing And Routing Device can need not be separately configured using this protection scheme, effectively simplify transforming plant protecting configuration.
The present invention is by the high frequency sampling of three-phase current, meeting requirement of the line selection algorithm to sample frequency, in addition, in phase fault
First the signal sampling is reused fourier algorithm extraction current amplitude, effectively reduce amount of calculation, ensure phase into low frequency signal
Between it is short-circuit when can be with quick acting.
Brief description of the drawings
Fig. 1 is the inventive method flow chart.
Fig. 2 is the small current neutral grounding system schematic diagram suitable for the present invention.
Embodiment
The present invention is described in further details with reference to the accompanying drawings and examples.
As shown in figure 1, a kind of small current neutral grounding power system phase fault of the present invention and single-phase grounding comprehensive protecting method,
Comprise the following steps：
Step 1：Collection small current neutral grounding protecting electrical power system installation place residual voltage in real timeAnd three-phase currentLow-frequency sampling of the residual voltage using sample frequency for 1.2kHz, three-phase current are using sample frequency
25.6kHz high frequency sampling；
Step 2：Difference of phase currents is calculated, and using three-phase current Sudden Changing Rate starting algorithm judges whether to occur alternate
Short trouble, if difference of phase currents is out-of-limit, it is determined as phase fault and enters step 3, otherwise into step 4；
Step 3：By sample frequency be 25.6kHz three-phase current sampling of data into 1.2kHz low-frequency sampling data, make
Three-phase current amplitude is extracted with fourier algorithm, and judges that the failure is troubles inside the sample space or area by stage current protection program
Outer failure, then acted if troubles inside the sample space in tripping operation, otherwise device involution；
Step 4：Residual voltage Sudden Changing Rate is calculated, and judges whether residual voltage Sudden Changing Rate is out-of-limit, if residual voltage is mutated
Amount is lasting out-of-limit in 5ms time windows, then is determined as singlephase earth fault and enters step 5, otherwise device involution；
Step 5：Start the single-phase grounding selecting algorithm with bootstrapping property, use the three-phase electricity that sample frequency is 25.6kHz
High frequency sampled data is flowed, judges whether this circuit is faulty line, then sends out alarm signal if faulty line, otherwise device is answered
Return.
Embodiment
A kind of small current neutral grounding system schematic diagram for being applied to the present invention is illustrated in figure 2, the system is 10kV low currents
Earthed distribution system, 110/11 Circuit Fault on Secondary Transformer use delta connection.
In traditional protection configuration mode, protection 1,2,3,4 all should configure the stage electric current of reaction phase fault
Protection, it should additionally configure when a Small Electric Current Earthing And Routing Device is used in singlephase earth fault and judge at 10kV buses I
Which bar circuit earth point is located at.
, then only need to be at protection 1,2,3,4 according to phase fault of the present invention and single-phase grounding comprehensive protecting method
Configure phase fault and single-phase grounding comprehensive protecting device, it is not necessary to which configuration small current earthing wire-selecting fills in addition at bus I
Put.
With reference to the action situation of guard method of the present invention during Fig. 2 introductions generation different faults：
When singlephase earth fault f occurs for circuit 11When, 1 installation place difference of phase currents of protection is not out-of-limit, and residual voltage is dashed forward
Variable is out-of-limit, and protection 1 enters step 4 through step 2, and starts small current earthing wire-selecting program, can determine that by line selection algorithm
This circuit is faulty line, is simultaneously emitted by alarm signal.Although other protection device installation places can also detect that residual voltage is dashed forward
Variable is out-of-limit, but because not being faulty line, after line selection algorithm judges, protection everywhere is reliable to be returned.
As phase fault f in the generating region of circuit 22When, 2 installation place difference of phase currents of protection are out-of-limit, and protection 2 is through step
Rapid two enter step 3, and by sampling, high frequency sampled data obtains low-frequency sampling data, and three-phase current is extracted using fourier algorithm
Amplitude and compared with setting valve, due to being troubles inside the sample space, protection 2 will send trip command, and breaker is cut at tripping protection 2
Except failure.Other protection device installation places are not due to that by short circuit current, can be failure to actuate reliably.
As phase fault f outside generating region at circuit 43When, 4 installation place difference of phase currents of protection are out-of-limit, the warp of protection 4
Step 2 enters step 3, and by sampling, high frequency sampled data obtains low-frequency sampling data, and three-phase electricity is extracted using fourier algorithm
Flow amplitude and compared with setting valve, due to being troubles inside the sample space, protection 4 will send trip command, and breaker at 4 is protected in tripping
Cut off failure.For protection 2, although can detect that difference of phase currents is out-of-limit, stage current protection program can pass through
It is external area error to protect definite value and the corresponding delay judgement failure, the returns of protection 2 after the excision failures of protection 4.Other protections
Device installation place is not due to that by short circuit current, can be failure to actuate reliably.
Claims (5)
1. a kind of small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method, it is characterised in that including such as
Lower step：
Step 1：Collection small current neutral grounding protecting electrical power system installation place residual voltage in real timeAnd three-phase currentLow-frequency sampling of the residual voltage using sample frequency for 1.2kHz, three-phase current are using sample frequency
25.6kHz high frequency sampling；
Step 2：Difference of phase currents is calculated, and judges whether generation phase fault using three-phase current Sudden Changing Rate starting algorithm
Failure, if difference of phase currents is out-of-limit, it is determined as phase fault and enters step 3, otherwise into step 4；
Step 3：By sample frequency be 25.6kHz three-phase current sampling of data into 1.2kHz low-frequency sampling data, use Fu
Family name's algorithm extracts three-phase current amplitude, and judges that the failure is event outside troubles inside the sample space or area by stage current protection program
Barrier, is then acted if troubles inside the sample space in tripping operation, otherwise device involution；
Step 4：Residual voltage Sudden Changing Rate is calculated, and judges whether residual voltage Sudden Changing Rate is out-of-limit, if residual voltage Sudden Changing Rate exists
It is lasting out-of-limit in 5ms time windows, then it is determined as singlephase earth fault and enters step 5, otherwise device involution；
Step 5：Start the single-phase grounding selecting algorithm with bootstrapping property, it is high using the three-phase current that sample frequency is 25.6kHz
Frequency sampling data, judge whether this circuit is faulty line, then send out alarm signal if faulty line, otherwise device involution.
2. small current neutral grounding power system phase fault according to claim 1 and single-phase grounding comprehensive protecting method, its
It is characterised by, three-phase current Sudden Changing Rate starting algorithm is as follows described in step 2：
In formula：Represent separate, n is current sampling point, and N is the sampling number of each power frequency period；For working as phase current
Preceding sampled value,For difference of phase currents, can be tried to achieve by formula (2)；For floating threshold, can be obtained by formula (3)；InTable
Show load current amplitude；k1、k2For safety factor；
For each phase current signal, when continuous 3 jump-value of current sampled values exceed predetermined threshold levelI.e.
When formula (1) is set up, then judge phase fault occurs, protection starts.
3. small current neutral grounding power system phase fault according to claim 2 and single-phase grounding comprehensive protecting method, its
It is characterised by, the safety factor k1=1.25, safety factor k2=0.06.
4. small current neutral grounding power system phase fault according to claim 1 and single-phase grounding comprehensive protecting method, its
It is characterised by, the algorithm that residual voltage Sudden Changing Rate is calculated described in step 4 is as follows：
Δu0[n]=u0[n]-u0[n-N] (4)
In formula：N is current sampling point, and N is the sampling number of each power frequency period；u0[n] is the real-time sampling value of residual voltage,
Δu0[n] is the real-time Sudden Changing Rate of residual voltage, can be tried to achieve by formula (4)；ΔU0[n] is residual voltage Sudden Changing Rate amplitude,
For phase voltage amplitude, m is startup coefficient；
When formula (5) is set up, then decision-making system residual voltage is out-of-limit, and starts single-phase earthing recognizer.
5. small current neutral grounding power system phase fault according to claim 4 and single-phase grounding comprehensive protecting method, its
It is characterised by, the startup coefficient m=0.2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510207792.4A CN104779594B (en) | 2015-04-27 | 2015-04-27 | Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510207792.4A CN104779594B (en) | 2015-04-27 | 2015-04-27 | Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104779594A CN104779594A (en) | 2015-07-15 |
| CN104779594B true CN104779594B (en) | 2017-12-12 |
Family
ID=53620906
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510207792.4A Active CN104779594B (en) | 2015-04-27 | 2015-04-27 | Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104779594B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105186469B (en) * | 2015-08-27 | 2017-09-29 | 南京国电南自电网自动化有限公司 | It is classified controlled reactor variable quantity zero sequence excessively stream inter-turn protection method |
| CN106597188B (en) * | 2016-11-16 | 2019-01-08 | 安徽合凯电气科技股份有限公司 | Single-phase earth fault discrimination method under cable, aerial and mixed connection route |
| CN107329040B (en) * | 2017-06-16 | 2019-08-16 | 国电南瑞科技股份有限公司 | A kind of power distribution automation main station system single-phase earth fault localization method based on transient state recorder data |
| CN111157835B (en) * | 2018-11-07 | 2023-01-24 | 国网电力科学研究院武汉南瑞有限责任公司 | Power grid single-phase earth fault judgment method |
| CN109557399A (en) * | 2018-12-14 | 2019-04-02 | 海南电网有限责任公司琼海供电局 | A kind of distribution network failure monitoring method and device |
| CN110579672A (en) * | 2019-07-11 | 2019-12-17 | 国网江苏省电力有限公司徐州供电分公司 | Power transmission line fault detection system and method based on energy characteristic analysis |
| CN112260219B (en) * | 2019-10-12 | 2022-08-26 | 南京南瑞继保工程技术有限公司 | Single-interval comprehensive protection method for ground fault of power distribution network |
| CN111751661A (en) * | 2020-06-29 | 2020-10-09 | 深圳供电局有限公司 | Method and system for judging ground fault based on power grid fault recording diagram |
| CN112034307A (en) * | 2020-09-04 | 2020-12-04 | 四川大学 | Cable early fault detection method based on stationary wavelet transform and symmetric component method |
| CN112510820A (en) * | 2020-11-11 | 2021-03-16 | 广西电网有限责任公司电力科学研究院 | System for automatic splitting of distributed power supply under 10kV feeder line fault |
| CN112421590B (en) * | 2020-12-10 | 2023-02-17 | 晟望电气有限公司 | Relay protection device and relay protection method for power distribution automation system line |
| CN113765053B (en) * | 2020-12-12 | 2022-09-27 | 保定钰鑫电气科技有限公司 | Method for processing interphase short circuit |
| CN113725823B (en) * | 2020-12-12 | 2023-04-25 | 保定钰鑫电气科技有限公司 | Method for processing interphase short circuit of three-phase non-effective grounding power supply system |
| CN113725824B (en) * | 2020-12-28 | 2023-12-15 | 保定钰鑫电气科技有限公司 | Device for processing interphase short circuit |
| CN114034964A (en) * | 2021-09-27 | 2022-02-11 | 国网青海省电力公司玉树供电公司 | Distribution line single-phase earth fault section identification device based on phase current variable quantity |
| CN118465620B (en) * | 2024-07-10 | 2024-09-13 | 东方电子股份有限公司 | Low-current grounding line selection method capable of self-adapting to high-low frequency fault quantity |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101478149A (en) * | 2009-01-16 | 2009-07-08 | 西安交通大学 | Wire selection method for power distribution network single phase earthing failure based on transient signal |
| CN102255284A (en) * | 2011-07-26 | 2011-11-23 | 重庆电力高等专科学校 | Method for realizing protection of transformer by comparing polarities of instantaneous values of current fault components |
| CN103296650A (en) * | 2013-05-19 | 2013-09-11 | 国家电网公司 | Ultra-high-voltage transmission line relay protection method based on break variable differential coefficient matrix |
| CN103439634A (en) * | 2013-09-02 | 2013-12-11 | 北京四方继保自动化股份有限公司 | Method for fault line selection by means of transient state polarity characteristics of zero-sequence current at grounding moment |
| CN103730882A (en) * | 2013-12-24 | 2014-04-16 | 西安交通大学 | Current protection system and method for being automatically adapted to distributed power connection |
| CN104155582A (en) * | 2014-08-29 | 2014-11-19 | 上海交通大学 | Distribution network line fault section positioning method based on full-waveform information |
-
2015
- 2015-04-27 CN CN201510207792.4A patent/CN104779594B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101478149A (en) * | 2009-01-16 | 2009-07-08 | 西安交通大学 | Wire selection method for power distribution network single phase earthing failure based on transient signal |
| CN102255284A (en) * | 2011-07-26 | 2011-11-23 | 重庆电力高等专科学校 | Method for realizing protection of transformer by comparing polarities of instantaneous values of current fault components |
| CN103296650A (en) * | 2013-05-19 | 2013-09-11 | 国家电网公司 | Ultra-high-voltage transmission line relay protection method based on break variable differential coefficient matrix |
| CN103439634A (en) * | 2013-09-02 | 2013-12-11 | 北京四方继保自动化股份有限公司 | Method for fault line selection by means of transient state polarity characteristics of zero-sequence current at grounding moment |
| CN103730882A (en) * | 2013-12-24 | 2014-04-16 | 西安交通大学 | Current protection system and method for being automatically adapted to distributed power connection |
| CN104155582A (en) * | 2014-08-29 | 2014-11-19 | 上海交通大学 | Distribution network line fault section positioning method based on full-waveform information |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104779594A (en) | 2015-07-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104779594B (en) | Small current neutral grounding power system phase fault and single-phase grounding comprehensive protecting method | |
| CN102388315B (en) | For identifying the method for the nature of trouble on line of electric force | |
| EP3266086B1 (en) | Method for protection in a mixed power transmission line | |
| CN106786413B (en) | The current protection method of the power distribution network containing distributed photovoltaic power | |
| KR101505176B1 (en) | Apparatus and method for detecting failure of bus | |
| CN112534280A (en) | System and method for locating faults on a multi-phase electrical network using positive and negative sequence voltage variations | |
| CN107315128A (en) | A kind of distributed earthing wire-selecting method and system based on GOOSE | |
| CN104577999B (en) | Bus bar protecting method and system based on transient zero-sequence current feature | |
| Nagpal et al. | Dispersed generation interconnection-utility perspective | |
| CN103412239A (en) | Detecting and positioning method of bus coupler flashover fault in subway alternating current power system | |
| Esmail et al. | Detection and experimental investigation of open conductor and single-phase earth return faults in distribution systems | |
| CN109638793A (en) | A kind of singlephase earth fault processing method suitable for small current neutral grounding system | |
| CN106505529A (en) | A kind of intelligent substation low-voltage bus bar guard method | |
| CN109217270A (en) | DC line sectional type timing limit overcurrent protection method and device | |
| CN103779846B (en) | The power network line wide area current protection method of revising fast based on admittance matrix | |
| CN103618299A (en) | Power distribution network different-place two-point grounded short circuit fault fast recognizing and isolating method based on wide-range information | |
| CN103683229B (en) | Method for protecting power grid wide-area relay based on unit output power and load change influence | |
| CN103944142A (en) | Transformer phase fault backup protection method based on offset voltage positive-sequence component | |
| CN112366664B (en) | Method and system for improving relay protection based on 3/2 wiring mode | |
| CN105098736A (en) | Buscouple protection method with outgoing line reactor | |
| CN107317309A (en) | A kind of earthing mode Collaborative Control conversion method and system based on GOOSE | |
| Oppel et al. | Evaluation of the performance of line protection schemes on the NYSEG six phase transmission system | |
| JP7181760B2 (en) | Protection control device for AC/DC converter station, protection control system for DC power transmission system, and protection control method for AC/DC converter station | |
| CN101634685B (en) | Method for detecting false operation of bus differential protection caused by the intrusion of interfering signal into the bus differential protection | |
| Zulkarnaini et al. | Study of coordination on protection relay in high voltage transmission 150 kv (payakumbuh–koto padang, west sumatra) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |