CN105071356B - A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD - Google Patents
A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD Download PDFInfo
- Publication number
- CN105071356B CN105071356B CN201510417132.9A CN201510417132A CN105071356B CN 105071356 B CN105071356 B CN 105071356B CN 201510417132 A CN201510417132 A CN 201510417132A CN 105071356 B CN105071356 B CN 105071356B
- Authority
- CN
- China
- Prior art keywords
- integration
- restraint coefficient
- difference stream
- sampled point
- differential
- 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)
Abstract
The invention discloses a kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD, pass through the integration restraint coefficient of sampled point difference stream in the set time before each sampling instant after the difference stream startup of real-time rolling calculation, when difference stream integration restraint coefficient is detected less than threshold value, Blocking Differential Protection, differential protection is reopened when the dynamic integration restraint coefficient of the poor flow roll in a continuous cycle is more than threshold, when latch-up protection when difference stream integration restraint coefficient is detected less than threshold value, it is effective to avoid due to differential protection malfunction caused by the out-of-limit wave chopping of sampling channel AD samplings, the method be particularly suitable for use in intelligent substation protection, it is simple and practical, with wide applicability.When the dynamic integration restraint coefficient of continuous cycle internal difference flow roll is more than threshold, then open and protection immediately.After the dynamic integration deceleration method of poor flow roll, the reliability of differential protection is improved.
Description
Technical field
The present invention relates to the new method applied to electric system protection device, and in particular to one kind prevents sampling channel AD from getting over
The method for limiting differential malfunction, integrates the method for restraint coefficient to prevent big electricity outside area by sampled point difference stream in fixed short-data windows
Differential malfunction caused by sampling channel AD wave choppings, can be applied to various differential protections simultaneously when flowing failure.
Background technology
With the increase of power system capacity, short-circuit current is increasing, according to IEC60255-27 masuring relays
Maximum 100 times CT rated current can be born by being claimed with protection device standard, far beyond current protection device institute energy
The current range (20~40 times) of detection, causes protection device AD sampling channel scopes to transfinite and causes waveform wave chopping to cut top, protection dress
Putting can not correctly faults electric current, the visibly moved easy malfunction of the external area error time difference.Do not adopted at present specifically designed for analog channel AD
Sample wave chopping causes the method and criterion that differential malfunction is handled.
The content of the invention
In order to solve prior art problem, the present invention provides a kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD,
Prevent from sampling during high current failure outside area by integrating the method for restraint coefficient by sampled point difference stream in fixed short-data windows
Differential malfunction caused by passage AD wave choppings, can be applied to various differential protections simultaneously.
To achieve the above objectives, the present invention is realized using following technical scheme.
The technical solution adopted by the present invention is：
A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD, comprises the following steps：
(1) based on sampled point Sudden Changing Rate difference stream integration and the braking of sampled point Sudden Changing Rate in first cycle after, difference stream starts
Current integration carries out restraint coefficient calculating；
Sampled point Sudden Changing Rate difference stream integration IdFor：
Sampled point Sudden Changing Rate stalling current integrates IrFor：
Restraint coefficient is：K=Id/Ir；
Wherein, △ id(n-k) the poor flow data of M Sudden Changing Rate sampled point, △ i are pushed away before beingr(n-k) M Sudden Changing Rate is pushed away before being to adopt
Sampling point stalling current data；
The difference stream integration restraint coefficient meets formula K<Kset, it is judged to caused by external area error that AD samplings are out-of-limit, locking is differential
Protection, wherein KsetFor difference stream integration restraint coefficient threshold value；
During external area error, because in the out-of-limit wave chopping region of non-ad, protection can correctly reflect each side current data, difference stream
Smaller, stalling current is big, and the difference stream integration restraint coefficient that calculating is obtained is smaller, reliable locking；During troubles inside the sample space, due to each side electricity
Stream is substantially in phase, in the absence of restraint coefficient smaller area, can correctly open.
(2), difference stream starts after a cycle, is sampled based on fixed data window, data window width is constant, uses sampled point
Difference stream integration and sampled point stalling current integration carry out restraint coefficient calculating, and the progress of fixed data window is pushed away before each sampling instant
Calculate.
When the difference stream integration restraint coefficient that any instant is calculated meets formula K<KsetWhen, external area error is judged to, locking is differential to be protected
Shield；If K values are more than threshold value in a continuous cycle, differential protection is reopened；
(3), the preceding fixed data window that pushes away is calculated, and 1 point of progress restraint coefficient calculating is moved after a point data window of often sampling,
Circulating rolling is calculated.
The method of the out-of-limit differential malfunctions of sampling channel AD is prevented by the present invention, once detect difference stream integration restraint coefficient
During less than threshold value, Blocking Differential Protection, when the dynamic integration restraint coefficient of the poor flow roll in continuous cycle 20ms is more than threshold
Reopen differential protection.It ensure that the reliability of differential protection, real-time and rapidity.
More preferably, KsetSpan be [0.15,0.2].
More preferably, cycle is 20ms.
Compared with prior art, beneficial effect of the present invention includes：It is less than when detecting sampled point difference stream integration restraint coefficient
Blocking Differential Protection during threshold value, is effectively avoided due to the differential protection malfunction that the out-of-limit wave choppings of sampling channel AD are caused, tool
There is wide applicability.When the dynamic integration restraint coefficient of the poor flow roll in a continuous cycle is more than threshold, then difference is reopened
Dynamic protection.After the dynamic integration deceleration method of poor flow roll, the reliability of differential protection action is improved.And the method is simply real
With amount of calculation is few, is highly susceptible to Microcomputer Protection realization.
Brief description of the drawings
Oscillogram when Fig. 1 is external area error phase current AD wave choppings；
Fig. 2 is the external area error AD wave chopping time differences to flow oscillogram；
Fig. 3 is to flow integration restraint coefficient the external area error AD wave chopping time differences.
Embodiment
The present invention is further described below in conjunction with the accompanying drawings.
A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD, comprises the following steps：
(1) based on sampled point Sudden Changing Rate difference stream integration and sampled point Sudden Changing Rate in first cycle 20ms after, difference stream starts
Stalling current integration carries out restraint coefficient calculating；
It is N that the analog input of protection carries out sampling number in current sample, every cycle with constant sample frequency.Protection
After startup, each sampling instant, the data window that selection length is fixed as M carries out difference stream integration restraint coefficient calculating.
Data window time span is calculated according to the maximum sample ranges of AD with system maximum short circuit current, with maximum sampling
Exemplified by 40 times of rated current, the actual maximum short circuit current of system is 100 times, then more than the 40 times rated current time differences of external area error
Stream starts.
Then poor stream Startup time is：
T=arcsin (40/100)/360*20ms=1.3ms.
Consider that fault current has positive and negative half-wave, data window is 2*1.3ms=2.6ms.Consider error and reliability, prevent
Tripping when troubles inside the sample space drains out electric current, restraint coefficient threshold is set to 0.15~0.2 in the case of high current.
According to the proportional brake coefficient of setting, the data window length fixed during by calculating protection actual use is can be controlled in
5ms or so, ensure that the difference stream integration restraint coefficient calculated in the worst case is less than 0.15.
For example for every point sampling of cycle 48, correspondence M can be chosen at 12 points.
After differential startup in the first cycle 20ms, since the 1st point of startup, in each sampling instant to current time
Sudden Changing Rate sampled point difference stream and Sudden Changing Rate sampled point stalling current in preceding fixed data window calculate difference stream integration restraint coefficient.
Sampled point Sudden Changing Rate difference stream integration IdFor：
Sampled point Sudden Changing Rate stalling current integrates IrFor：
Restraint coefficient is：K=Id/Ir；
Wherein, △ id(n-k) the poor flow data of M Sudden Changing Rate sampled point, △ i are pushed away before beingr(n-k) M Sudden Changing Rate is pushed away before being to adopt
Sampling point stalling current data；
The difference stream integration restraint coefficient meets formula K<Kset, it is judged to caused by external area error that AD samplings are out-of-limit, locking is differential
Protection, wherein KsetFor difference stream integration restraint coefficient threshold value, 0.15~0.2 is set to；
During external area error, because in the out-of-limit wave chopping region of non-ad, protection can correctly reflect each side current data, difference stream
Smaller, stalling current is big, and the difference stream integration restraint coefficient that calculating is obtained is smaller, reliable locking；During troubles inside the sample space, due to each side electricity
Stream is substantially in phase, in the absence of restraint coefficient smaller area, can correctly open.
(2), difference stream starts after a cycle 20ms, is sampled based on fixed data window, data window width is constant, using adopting
Sampling point difference stream integration and sampled point stalling current integration carry out restraint coefficient calculating, and fixed data window is pushed away before each sampling instant
Calculated；
Now,
Sampled point difference stream integration：
Sampled point stalling current is integrated：
Restraint coefficient：K=Id/Ir；
id(n-k) the poor flow data of M sampled point, i are pushed away before beingr(n-k) M sampled point stalling current data are pushed away before being.
When the difference stream integration restraint coefficient that any instant is calculated meets formula K<KsetWhen, external area error is judged to, locking is differential to be protected
Shield；If K values are more than threshold value in a continuous cycle, differential protection is reopened；
(3), the preceding fixed data window that pushes away is calculated, and 1 point of progress restraint coefficient calculating is moved after a point data window of often sampling,
Circulating rolling is calculated.
Oscillogram when Fig. 1 is external area error phase current AD out-of-limit wave choppings, causes difference miscarriage life in Fig. 2, is computed difference stream product
Divide restraint coefficient (as shown in Figure 3), there is obvious integration restraint coefficient smaller value, differential deallock effectively prevent differential
False protection, improves differential protection reliability.Cyclic integral deceleration method is moved in poor flow roll, simple and practical, is only had during calculating simple
The summation of recursion algebraically, each sampling instant need to only add current point, remove most former point in data window, and amount of calculation is few, very easily
Realized in Microcomputer Protection.
Described above is only the preferred embodiment of the present invention, it should be pointed out that：For the ordinary skill people of the art
For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should
It is considered as protection scope of the present invention.
Claims (3)
1. a kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD, it is characterised in that comprise the following steps：
(1) based on sampled point Sudden Changing Rate difference stream integration and sampled point Sudden Changing Rate stalling current in first cycle after, difference stream starts
Integration carries out restraint coefficient calculating；
Sampled point Sudden Changing Rate difference stream integration IdFor：
Sampled point Sudden Changing Rate stalling current integrates IrFor：
Difference stream integrates restraint coefficient：K=Id/Ir；
Wherein, Δ id(n-k) the poor flow data of M Sudden Changing Rate sampled point, Δ i are pushed away before beingr(n-k) M Sudden Changing Rate sampled point is pushed away before being
Stalling current data；
The difference stream integration restraint coefficient meets formula K ＜ Kset, it is judged to caused by external area error that AD samplings are out-of-limit, locking is differential to be protected
Shield, wherein KsetFor difference stream integration restraint coefficient threshold value；
(2), difference stream starts after a cycle, is sampled based on fixed data window, data window width is constant, is flowed using sampled point difference
Integration and sampled point stalling current integration carry out restraint coefficient calculating, and fixed data window is pushed away before each sampling instant and is counted
Calculate；
When the difference stream integration restraint coefficient that any instant is calculated meets formula K ＜ KsetWhen, it is judged to external area error, Blocking Differential Protection；
If K values are more than threshold value in a continuous cycle, differential protection is reopened；
(3), the preceding fixed data window that pushes away is calculated, and 1 point of progress restraint coefficient calculating, circulation are moved after a point data window of often sampling
Rolling calculation.
2. the method according to claim 1 for preventing the out-of-limit differential malfunctions of sampling channel AD, it is characterised in that
KsetSpan be [0.15,0.2].
3. the method according to claim 1 for preventing the out-of-limit differential malfunctions of sampling channel AD, it is characterised in that
The cycle is 20ms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510417132.9A CN105071356B (en) | 2015-07-15 | 2015-07-15 | A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510417132.9A CN105071356B (en) | 2015-07-15 | 2015-07-15 | A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105071356A CN105071356A (en) | 2015-11-18 |
| CN105071356B true CN105071356B (en) | 2017-10-31 |
Family
ID=54500669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510417132.9A Active CN105071356B (en) | 2015-07-15 | 2015-07-15 | A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105071356B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107123974B (en) * | 2017-06-28 | 2019-01-01 | 积成软件有限公司 | A kind of open trip method of bus troubles inside the sample space CT saturation based on saturation mechanism |
| CN113267698A (en) * | 2021-06-02 | 2021-08-17 | 南京国电南自电网自动化有限公司 | Method, system and storage medium for distinguishing main transformer CT saturation |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101183786A (en) * | 2007-11-16 | 2008-05-21 | 国电南瑞科技股份有限公司 | Anti-CT saturated sampling value differential protection of predicting CT linear transform area |
| CN101789584A (en) * | 2010-01-13 | 2010-07-28 | 北京四方继保自动化股份有限公司 | Method for differential protection of sampling value of abrupt change and differential relays |
| CN103529321A (en) * | 2013-10-10 | 2014-01-22 | 长园深瑞继保自动化有限公司 | Current transformer saturation detecting method |
-
2015
- 2015-07-15 CN CN201510417132.9A patent/CN105071356B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101183786A (en) * | 2007-11-16 | 2008-05-21 | 国电南瑞科技股份有限公司 | Anti-CT saturated sampling value differential protection of predicting CT linear transform area |
| CN101789584A (en) * | 2010-01-13 | 2010-07-28 | 北京四方继保自动化股份有限公司 | Method for differential protection of sampling value of abrupt change and differential relays |
| CN103529321A (en) * | 2013-10-10 | 2014-01-22 | 长园深瑞继保自动化有限公司 | Current transformer saturation detecting method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105071356A (en) | 2015-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106353609B (en) | A kind of motor phase failure detection method and system | |
| RU2564041C2 (en) | Method for forecasting and detecting saturation of current transformer at sympathetic inrush current | |
| CN108183463B (en) | Method for preventing misoperation in ratio differential protection of transformer of intelligent substation | |
| US10333291B2 (en) | Multiple generator ground fault detection | |
| CN102684145B (en) | Sampling data exception detecting method and relay protection method based on redundant CT windings | |
| CN102854426B (en) | Method for judging direct current arc fault based on real-time measured multi-band frequency component rate | |
| CN102522726B (en) | Method for locking magnetizing inrush current of transformer | |
| CN102820643A (en) | High voltage direct current power transmission line protection method based on voltage and current mutation direction | |
| CN105573853B (en) | Sampling method for processing abnormal data based on dual data window | |
| CN105140893A (en) | Differential protection current transformer (CT) saturation recognition method | |
| CN101662143B (en) | Differential protection method for preventing false operation during current disappearance | |
| CN105071356B (en) | A kind of method for preventing the out-of-limit differential malfunctions of sampling channel AD | |
| CN105353271B (en) | A kind of current differential protection saturation method of discrimination | |
| CN101764396A (en) | Method for realizing longitudinal distance protection at adaptive weak power side | |
| CN107093891B (en) | A kind of flexibility transformer substation system DC line protection method and device | |
| CN106602521B (en) | Bus sampling value differential protection method based on current transformer linear transform area | |
| CN109444659B (en) | Annular direct-current power distribution network fault detection method based on voltage prediction | |
| CN100420114C (en) | Anti-TA transient imbalance differential protection for generator | |
| CN105655976A (en) | Generator stator ground protection method | |
| CN106026040B (en) | It is a kind of to prevent the abnormal differential protection method for bus several greatly of sampling | |
| WO2017059655A1 (en) | Method for detecting transformer tail current | |
| CN109193591B (en) | Method for judging starting of interphase current break variable through floating threshold | |
| CN105954563A (en) | Method of identifying tail current based on current derivative and differential current zero-crossing | |
| CN107086550A (en) | A kind of high pressure or UHVDC Transmission Lines voltage jump amount protection faulty action preventing method | |
| CN108120902A (en) | A kind of transmission line malfunction quick discrimination method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |