CN104375025B - Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system - Google Patents
Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system Download PDFInfo
- Publication number
- CN104375025B CN104375025B CN201410602507.4A CN201410602507A CN104375025B CN 104375025 B CN104375025 B CN 104375025B CN 201410602507 A CN201410602507 A CN 201410602507A CN 104375025 B CN104375025 B CN 104375025B
- Authority
- CN
- China
- Prior art keywords
- fault
- voltage
- resonance
- phase
- value
- 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
- 230000007935 neutral effect Effects 0.000 title claims abstract description 30
- 230000005350 ferromagnetic resonance Effects 0.000 title claims abstract description 14
- 238000002405 diagnostic procedure Methods 0.000 title claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 35
- 238000005070 sampling Methods 0.000 claims description 8
- 238000001514 detection method Methods 0.000 claims description 6
- 238000001228 spectrum Methods 0.000 claims description 6
- 230000005291 magnetic effect Effects 0.000 claims description 4
- 230000005611 electricity Effects 0.000 description 2
- 206010008190 Cerebrovascular accident Diseases 0.000 description 1
- 241001269238 Data Species 0.000 description 1
- 229910000805 Pig iron Inorganic materials 0.000 description 1
- 208000006011 Stroke Diseases 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000012850 discrimination method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Locating Faults (AREA)
Abstract
The invention provides a diagnostic method for ferromagnetic resonance in a neutral non-grounding 10kV system. A phase-A voltage to ground, a phase-B voltage to ground, a phase-C voltage to ground, a neutral point voltage and a neutral point frequency are caught when the voltage at the two ends of a PT opening triangle exceeds the set limiting value. Firstly, faults are divided into a frequency division resonance and high frequency resonance class and a fundamental resonance and high frequency resonance class, then, frequency division resonance and high frequency resonance are distinguished according frequencies, the type of fundamental resonance and single-phase ground faults is processed according to an energy method and a loop grounding current method, and the preliminary conclusion is obtained through the energy method and then is checked through the loop grounding current method; when the results obtained through the two methods are the same, it is shown that judgment is correct, and the fundamental resonance and single-phase ground faults are distinguished. The distinguished faults and the obtained non-ferromagnetic resonance and single-phase ground fault conclusions are sent to a terminal to be displayed, and maintainers can process the corresponding faults in time.
Description
Technical field
The present invention relates to the diagnostic field of ferromagnetic resonance and single-phase earthing is and in particular to a kind of 10kv of isolated neutral
The diagnostic method of ferromagnetic resonance in system.
Background technology
In the electrical network of 10kv isolated neutral, in order to watt metering and protection are carried out to three phase-to-ground voltages, sending out
The voltage transformer of (y/y/ δ) wiring is usually connected on motor or substation bus bar, and its high pressure winding neutral ground, in
Be electric network over the ground parameter in addition to power equipment and lead capacitance c, the also inductance l of voltage transformer.Due to electromagnetic type electricity
Press the non-linear of transformer inductance, it is possible to excite initiation ferro-resonance over-voltage under meeting some requirements, ferromagnetic humorous
The frequency shaken can be fundamental wave or higher hamonic wave or subharmonic.When the electrical network that electromagnetic potential transformer is located is sent out
During pig iron magnetic resonance, frequently result in burning or exploding of transformer.During singlephase earth fault, can lead under a phase-to-ground voltage
Fall, another two phase-to-ground voltages rise, and ground connection will also result in transformer when disappearing and burns or explode.Due to showing of singlephase earth fault
As the similar phenomena with ferromagnetic resonance, traditional single diagnostic method passes through the size of three-phase voltage and sets residual voltage threshold value
It is difficult to difference singlephase earth fault and fundamental resonance fault, later using wavelet analysis method and fast Fourier transform method, but by
In the unicity of determination methods, accuracy rate is not also very high, and when phenomenon difference is not apparent it is easy to make a mistake
Judgement.
Content of the invention
In the 10kv system of the isolated neutral of the present invention, the advantage of the diagnostic method of ferromagnetic resonance is, multi-level differentiation
Fault is divided into each big class by fault first, and subdividing in individual big apoplexy due to endogenous wind is any fault.Using multiple discrimination methods, never
With angle certain fault is judged, thus the type of reliably tracing trouble.Effectively high-frequency resonant can be told,
Subharmonic Resonance, first-harmonic resonance and singlephase earth fault.
Technical solution of the present invention is specific as follows:
In a kind of 10kv system of isolated neutral, the diagnostic method of ferromagnetic resonance, continuous with the speed of more than 8kb/s
Synchronous acquisition a phase-to-ground voltage, b phase-to-ground voltage, c phase-to-ground voltage, neutral point voltage, neutral dot frequency, pt open delta
Shape two ends residual voltage；Exceed setting value by the voltage at pt open-delta two ends is detected, calculate a, b, c three-phase voltage
Fault is thus divided into three kinds of big types by amplitude meansigma methodss, further according to the big type of fault, by related data and method,
Distinguish Subharmonic Resonance, high-frequency resonant, fundamental resonance and singlephase earth fault more successively.
More optimizedly, the meansigma methodss calculating the voltage magnitude of a, b, c three-phase are designated as ua、ub、uc, with normal voltage amplitude u
(theoretical value 5.77kv) is compared:
If ● ua、ub、ucIt is all higher than normal voltage amplitude u, and now neutral point voltage rises to the value of phase voltage, then
Judge that the fault that now occurs, as Subharmonic Resonance or high-frequency resonant, is labeled as fault x；
If ● ua、ub、ucIn have one to be mutually less than normal voltage amplitude u, remaining is biphase to be all higher than normal voltage amplitude u, then sentence
Break as fundamental resonance and singlephase earth fault, be labeled as fault y；
● other voltage condition are all labeled as fault z.
More optimizedly,
● for fault x, centering dot frequency signal carries out relevant treatment and obtains signal spectrum, by signal spectrum, if
Most of frequency is judged as Subharmonic Resonance when being less than 50hz, if being judged as high-frequency resonant when most of frequency is more than 50hz；
● for fault y, pass through energy method respectively and two methods of loop earth current method judge, only work as two methods
Singlephase earth fault or fundamental resonance fault just can be drawn when judging consistent.
More optimizedly, if being judged as fault y, the square value of each neutral point voltage of sampling gained is as the energy of this point
Value is calculated, and compares the ratio of energy before and after fault occurs；Specifically comprise the following steps that
First, fault is taken the sampled value of first five cycle to occur as first group, first five cycle after taking fault to occur
As first group, sampling terminates front last five cycle sampled values as second group, if the gross energy of two groups of voltages divides to sampled value
Wei not e1And e2, energy ratio
If ● when m >=1.1 or m≤0.9, fixing tentatively as there is fundamental resonance, being labeled as y1；
● if 0.9 < m < when 1.1, takes first group of voltage cycle amplitude sampled value to calculate amplitude meansigma methodss b1, take second group
Voltage cycle sampled value simultaneously seeks amplitude meansigma methodss b2；Thus obtain voltage magnitude rate of change:
If -0.05 < n < when 0.05, fixes tentatively as singlephase earth fault, is labeled as y2；
If when n >=0.05 or n≤- 0.05, fix tentatively as fundamental resonance, be labeled as y1；
Then, grounding current compensation and detection branch are put into, detection loop zero-sequence current now, when loop earth current
When value is less, fixes tentatively as fundamental resonance fault, be labeled as y3, when loop current value is larger, fix tentatively as singlephase earth fault, mark
It is designated as y4；
● work as y1&&y3When=1, it is judged as fundamental resonance fault；
● work as y2&&y4When=1, it is judged as singlephase earth fault.
More optimizedly, if fault z, then non-ferric magnetic resonance fault and singlephase earth fault are returned to control centre.
In sum, in the 10kv system of the isolated neutral of the present invention diagnostic method of ferromagnetic resonance have following
Advantage:
1st, the present invention adopts two methods to judge fundamental resonance and singlephase earth fault, makes result more accurate.
2nd, the present invention, using diagnostic method twice, first by failure modes, specifically judges further according to classification results, makes diagnostic result
Faster more accurate.
Brief description
Fig. 1 be a kind of isolated neutral 10kv system in ferromagnetic resonance diagnostic method flow chart；In figure:
● fault x is high-frequency resonant or Subharmonic Resonance,
● fault y is fundamental resonance or single-phase earthing resonance,
● fault z is non-fundamental resonance and single-phase earthing resonance,
● m represents energy ratio,
● n represents voltage magnitude rate of change,
●y1And y3Represent fundamental resonance,
●y2And y4Represent singlephase earth fault.
Specific embodiment
Below in conjunction with the accompanying drawings the preferred embodiments of the present invention are described in detail, so that advantages and features of the invention energy
It is easier to be readily appreciated by one skilled in the art, thus protection scope of the present invention is made apparent clearly defining.
As shown in figure 1, in a kind of 10kv system of isolated neutral ferromagnetic resonance diagnostic method, with more than 8kb/s
Speed continuous synchronization collection a phase-to-ground voltage, b phase-to-ground voltage, c phase-to-ground voltage, neutral point voltage, neutral dot frequency,
Pt open-delta two ends residual voltage；The residual voltage change at real-time monitoring open-delta two ends, in open-delta electricity
When pressure does not have significant change, preserve voltage now and frequency values, when the continuous n of the residual voltage at open-delta two ends is individual instantaneous
Value, more than (n is preset value, and the value that transfinites for n-th is called to transfinite a little) during 30v, at this moment represents faulty generation, and continuous preservation is transfinited
Point before n-1 cycle waveform with transfinite a little after n-1 cycle waveform a phase-to-ground voltage, b phase-to-ground voltage, c is relatively
Voltage, neutral point voltage, neutral dot frequency, the data of pt open-delta two ends residual voltage.These Wave datas are sent into
Cpu process.
To a phase-to-ground voltage, b phase-to-ground voltage, c phase-to-ground voltage, the waveform peak sampling of neutral point voltage, average meter
The meansigma methodss calculating the voltage magnitude of a, b, c three-phase are designated as ua、ub、uc, carry out with normal voltage amplitude u (theoretical value 5.77kv)
Relatively:
If ● ua、ub、ucIt is all higher than normal voltage amplitude u, and now neutral point voltage rises to the value of phase voltage, then
Judge that the fault that now occurs, as Subharmonic Resonance or high-frequency resonant, is labeled as fault x；
If ● ua、ub、ucIn have one to be mutually less than normal voltage amplitude u, remaining is biphase to be all higher than normal voltage amplitude u, then sentence
Break as fundamental resonance and singlephase earth fault, be labeled as fault y；
● other voltage condition are all labeled as fault z, return non-ferric magnetic resonance fault and singlephase earth fault to control
Center.
● for fault x, centering dot frequency signal carries out relevant treatment and obtains signal spectrum, by signal spectrum, if
Most of frequency is judged as Subharmonic Resonance when being less than 50hz, if being judged as high-frequency resonant when most of frequency is more than 50hz；
● for fault y, pass through energy method respectively and two methods of loop earth current method judge, only work as two methods
Singlephase earth fault or fundamental resonance fault just can be drawn when judging consistent.
If being judged as fault y, the square value of each neutral point voltage of sampling gained is counted as the energy value of this point
Calculate, compare the ratio of energy before and after fault occurs；Specifically comprise the following steps that
First, fault is taken the sampled value of first five cycle to occur as first group, first five cycle after taking fault to occur
As first group, sampling terminates front last five cycle sampled values as second group, if the gross energy of two groups of voltages divides to sampled value
Wei not e1And e2, energy ratio
If ● when m >=1.1 or m≤0.9, fixing tentatively as there is fundamental resonance, being labeled as y1；
● if 0.9 < m < when 1.1, takes first group of voltage cycle amplitude sampled value to calculate amplitude meansigma methodss b1, take second group
Voltage cycle sampled value simultaneously seeks amplitude meansigma methodss b2；Thus obtain voltage magnitude rate of change:
If -0.05 < n < when 0.05, fixes tentatively as singlephase earth fault, is labeled as y2；
If when n >=0.05 or n≤- 0.05, fix tentatively as fundamental resonance, be labeled as y1；
Then, grounding current compensation and detection branch are put into, detection loop zero-sequence current now, when loop earth current
When value is less, fixes tentatively as fundamental resonance fault, be labeled as y3, when loop current value is larger, fix tentatively as singlephase earth fault, mark
It is designated as y4；
● work as y1&&y3When=1, it is judged as fundamental resonance fault；
● work as y2&&y4When=1, it is judged as singlephase earth fault.
Above content is to further describe it is impossible to assert with reference to specific preferred implementation is made for the present invention
The specific embodiment of the present invention is only limitted to this, for general technical staff of the technical field of the invention, is not taking off
On the premise of present inventive concept, some simple deduction or replace can also be made, all should be considered as belonging to the present invention by institute
The claims submitted to determine scope of patent protection.
Claims (2)
1. in a kind of 10kv system of isolated neutral ferromagnetic resonance diagnostic method, with the speed of more than 8kb/s continuously with
Step collection a phase-to-ground voltage, b phase-to-ground voltage, c phase-to-ground voltage, neutral point voltage, neutral dot frequency, pt open-delta
Two ends residual voltage；Exceed setting value by the voltage at pt open-delta two ends is detected, calculate the width of a, b, c three-phase voltage
Fault is thus divided into three kinds of big types by value meansigma methodss, further according to the big type of fault, by related data and method, then
Distinguish Subharmonic Resonance, high-frequency resonant, fundamental resonance and singlephase earth fault successively；
The meansigma methodss calculating the voltage magnitude of a, b, c three-phase are designated as ua、ub、uc, with normal voltage amplitude u (theoretical value
5.77kv) it is compared:
If ua、ub、ucIt is all higher than normal voltage amplitude u, and now neutral point voltage rises to the value of phase voltage, then judge
The fault now occurring is Subharmonic Resonance or high-frequency resonant, is labeled as fault x；
If ua、ub、ucIn have one to be mutually less than normal voltage amplitude u, remaining is biphase to be all higher than normal voltage amplitude u, then be judged as
Fundamental resonance and singlephase earth fault, are labeled as fault y；
Other voltage condition are all labeled as fault z；
For fault x, centering dot frequency signal carries out relevant treatment and obtains signal spectrum, by signal spectrum, if big portion
Crossover rate is judged as Subharmonic Resonance when being less than 50hz, if being judged as high-frequency resonant when most of frequency is more than 50hz；
For fault y, pass through energy method respectively and two methods of loop earth current method judge, only when two methods judge
Singlephase earth fault or fundamental resonance fault just can be drawn when consistent；
It is characterized in that,
If being judged as fault y, the square value of each neutral point voltage of sampling gained is calculated as the energy value of this point, than
The ratio of energy before and after occurring compared with fault；Specifically comprise the following steps that
First, fault is taken the sampled value of first five cycle to occur as first group, the sampling of first five cycle after taking fault to occur
As first group, sampling terminates front last five cycle sampled values as second group, if the gross energy of two groups of voltages is respectively to value
e1And e2, energy ratio
If when m >=1.1 or m≤0.9, fixing tentatively as there is fundamental resonance, being labeled as y1；
If 0.9 < m < when 1.1, takes first group of voltage cycle amplitude sampled value to calculate amplitude meansigma methodss b1, take second group of voltage
Cycle sampled value simultaneously seeks amplitude meansigma methodss b2；Thus obtain voltage magnitude rate of change:
If -0.05 < n < when 0.05, fixes tentatively as singlephase earth fault, is labeled as y2；
If when n >=0.05 or n≤- 0.05, fix tentatively as fundamental resonance, be labeled as y1；
Then, put into grounding current compensation and detection branch, detection loop zero-sequence current now, when loop earth current value relatively
Hour, fix tentatively as fundamental resonance fault, be labeled as y3, when loop current value is larger, fixes tentatively as singlephase earth fault, be labeled as
y4；
Work as y1&&y3When=1, it is judged as fundamental resonance fault；
Work as y2&&y4When=1, it is judged as singlephase earth fault.
2. in the 10kv system of isolated neutral according to claim 1 ferromagnetic resonance diagnostic method, its feature exists
In if fault z, then return non-ferric magnetic resonance fault and singlephase earth fault are to control centre.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410602507.4A CN104375025B (en) | 2014-10-31 | 2014-10-31 | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system |
| PCT/CN2015/085340 WO2016065959A1 (en) | 2014-10-31 | 2015-07-28 | Diagnostic method for ferromagnetic resonance in 10 kv neutral ungrounded system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410602507.4A CN104375025B (en) | 2014-10-31 | 2014-10-31 | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104375025A CN104375025A (en) | 2015-02-25 |
| CN104375025B true CN104375025B (en) | 2017-02-01 |
Family
ID=52554063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410602507.4A Active CN104375025B (en) | 2014-10-31 | 2014-10-31 | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN104375025B (en) |
| WO (1) | WO2016065959A1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104375025B (en) * | 2014-10-31 | 2017-02-01 | 国家电网公司 | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system |
| CN106018991A (en) * | 2016-04-15 | 2016-10-12 | 国网江苏省电力公司盐城供电公司 | Power distribution network ferroresonance and single phase earth fault calculating analysis method and device |
| CN106549371A (en) * | 2016-11-09 | 2017-03-29 | 国家电网公司 | The method and apparatus for preventing PT ferromagnetic resonances from causing UFLS malfunction |
| 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 |
| CN108318762B (en) * | 2018-02-28 | 2020-09-08 | 南京南瑞继保电气有限公司 | Method for judging power frequency ferromagnetic resonance of voltage transformer |
| CN108169630B (en) * | 2018-03-08 | 2023-10-20 | 云南电网有限责任公司电力科学研究院 | Device and method for on-line monitoring resonance of neutral point ungrounded power grid |
| CN109856585B (en) * | 2019-02-28 | 2020-12-18 | 国网福建省电力有限公司莆田供电公司 | Resonance state judgment method in voltage transformer series resonance boosting process |
| CN110988597A (en) * | 2019-12-15 | 2020-04-10 | 云南电网有限责任公司文山供电局 | Resonance type detection method based on neural network |
| CN111736037A (en) * | 2020-08-05 | 2020-10-02 | 国网江西省电力有限公司电力科学研究院 | Ferromagnetic resonance quick identification method suitable for medium-voltage distribution network |
| CN113671239B (en) * | 2021-08-10 | 2023-08-15 | 国网湖南省电力有限公司 | Intelligent overvoltage identification method, device and system for high-voltage switch PT cabinet |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005300205A (en) * | 2004-04-07 | 2005-10-27 | Hitachi Ltd | Method and device for locating ground fault point |
| CN101452038A (en) * | 2007-11-29 | 2009-06-10 | 上海蓝瑞软件技术有限公司 | Low current neutral grounding electric network single-phase earth fault diagnostic method |
| CN102004205A (en) * | 2010-09-16 | 2011-04-06 | 广元电业局 | Judging methods of single phase-to-earth fault and resonance overvoltage fault in small current grounding system |
| CN103199514A (en) * | 2013-02-25 | 2013-07-10 | 重庆大学 | Method of eliminating ferromagnetic resonances |
| CN103840437A (en) * | 2014-03-15 | 2014-06-04 | 李景禄 | Quick diagnostic and processing method of power distribution network ferromagnetic resonance and one-phase earth faults |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8018235B2 (en) * | 2006-11-02 | 2011-09-13 | Texas Instruments Incorporated | Methods and apparatus to facilitate ground fault detection with a single coil and an oscillator |
| CN101022216B (en) * | 2007-02-07 | 2010-04-07 | 燕山大学 | Small earthing current electric network single phase fault wire selecting method and apparatus |
| EP2293402A1 (en) * | 2009-09-07 | 2011-03-09 | ABB Research Ltd. | Protective system for voltage transformers |
| CN103323728B (en) * | 2013-06-05 | 2016-02-24 | 昆明理工大学 | Based on singlephase earth fault and the Xuhanting oral solution recognition methods of whole wave energy Ratios |
| CN103344875B (en) * | 2013-07-02 | 2015-07-22 | 福州大学 | Classification line selection method for single-phase earth fault of resonance earthing system |
| CN104375025B (en) * | 2014-10-31 | 2017-02-01 | 国家电网公司 | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system |
-
2014
- 2014-10-31 CN CN201410602507.4A patent/CN104375025B/en active Active
-
2015
- 2015-07-28 WO PCT/CN2015/085340 patent/WO2016065959A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005300205A (en) * | 2004-04-07 | 2005-10-27 | Hitachi Ltd | Method and device for locating ground fault point |
| CN101452038A (en) * | 2007-11-29 | 2009-06-10 | 上海蓝瑞软件技术有限公司 | Low current neutral grounding electric network single-phase earth fault diagnostic method |
| CN102004205A (en) * | 2010-09-16 | 2011-04-06 | 广元电业局 | Judging methods of single phase-to-earth fault and resonance overvoltage fault in small current grounding system |
| CN103199514A (en) * | 2013-02-25 | 2013-07-10 | 重庆大学 | Method of eliminating ferromagnetic resonances |
| CN103840437A (en) * | 2014-03-15 | 2014-06-04 | 李景禄 | Quick diagnostic and processing method of power distribution network ferromagnetic resonance and one-phase earth faults |
Non-Patent Citations (1)
| Title |
|---|
| 3-10kV中性点不接地系统铁磁谐振过电压的识别;张海斌;《电工技术》;20121231(第9期);59-60 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104375025A (en) | 2015-02-25 |
| WO2016065959A1 (en) | 2016-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104375025B (en) | Diagnostic method for ferromagnetic resonance in neutral non-grounding 10kV system | |
| CN109307824B (en) | Clustering-based power distribution network single-phase earth fault section positioning method | |
| EP3069426B1 (en) | Method and apparatus of reactor turn-to-turn protection | |
| CN101546906B (en) | Method for fault line selection of electric distribution network by using S transformation energy relative entropy | |
| CN104242267B (en) | A kind of wind-power electricity generation sends out transmission line distance protecting method | |
| CN107179466A (en) | The fault line selection method for single-phase-to-ground fault of small current neutral grounding system | |
| Zou et al. | Novel transient-energy-based directional pilot protection method for HVDC line | |
| CN104280644B (en) | Direct-current transmission project typical transient fault recognizing method | |
| CN108490304A (en) | Generator stator winding single-phase earthing abort situation localization method | |
| CN103683198B (en) | The excitation surge current method for quickly identifying of consecutive points distance in a kind of plane based on difference current adjacent order difference composition | |
| CN105606944B (en) | The fault line selection method for single-phase-to-ground fault and device of distribution system | |
| CN103197202A (en) | Distribution network fault line selection method based on wavelet coefficient correlation analysis in three-phase breaking current component characteristic frequency band | |
| CN107677904A (en) | A kind of voltage dip origin cause of formation discrimination method and system | |
| CN104407293B (en) | A kind of induction machine strip-broken failure detecting method based on compound principle | |
| CN109782122A (en) | A kind of detection method of S Injection Signal | |
| CN106018991A (en) | Power distribution network ferroresonance and single phase earth fault calculating analysis method and device | |
| CN112485590A (en) | Power distribution network single-phase line-breaking fault identification method | |
| CN109188192A (en) | It is a kind of without adjusting power distribution network selection method | |
| CN105606955A (en) | Numerical differentiation and empirical mode decomposition-based fault line distinguishing method | |
| CN108646134B (en) | Method for positioning single-phase earth fault of generator stator winding based on phasor analysis | |
| CN102435896A (en) | Intermittent grounding fault rapid identification method of ship medium-voltage power system | |
| CN107179476B (en) | Distribution network fault distance measurement method | |
| CN105242135A (en) | Three-phase power transformer parameter online identification apparatus and realization algorithm thereof | |
| CN104914354B (en) | The electric voltage temporary drop detecting method that three-phase voltage Sudden Changing Rate and residual voltage are combined | |
| Zhou et al. | Method of cable incipient faults detection and identification based on wavelet transform and gray correlation analysis |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |