CN110426604B - Single-phase earth fault line selection method of resonance earthing system - Google Patents
Single-phase earth fault line selection method of resonance earthing system Download PDFInfo
- Publication number
- CN110426604B CN110426604B CN201910825474.2A CN201910825474A CN110426604B CN 110426604 B CN110426604 B CN 110426604B CN 201910825474 A CN201910825474 A CN 201910825474A CN 110426604 B CN110426604 B CN 110426604B
- Authority
- CN
- China
- Prior art keywords
- amplitude
- fault
- harmonic
- feeder line
- line selection
- 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
- 238000010187 selection method Methods 0.000 title claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 34
- 238000005070 sampling Methods 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 7
- 230000002238 attenuated effect Effects 0.000 claims description 6
- 238000010606 normalization Methods 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 4
- 238000012216 screening Methods 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 3
- 230000001629 suppression Effects 0.000 abstract description 19
- 238000004458 analytical method Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000001052 transient effect Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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
-
- 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
- G01R31/088—Aspects of digital computing
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Locating Faults (AREA)
Abstract
The invention discloses a single-phase earth fault line selection method of a resonance grounding system, belongs to the technical field of power system relay protection, and aims to solve the technical problem of fault feeder line identification when a single-phase earth fault occurs in the resonance grounding system. The method comprises the following steps: acquiring zero sequence current at the head end of a feeder line; acquiring a fundamental wave amplitude, a second harmonic amplitude and a third harmonic amplitude, and normalizing the fundamental wave amplitude, the second harmonic amplitude and the third harmonic amplitude according to the ratio of the fundamental wave amplitude, the second harmonic amplitude and the third harmonic amplitude to the sum of all feeder line harmonic amplitudes; solving a characteristic coefficient by using a least square fitting method; and finally, identifying the fault feeder line through the characteristic coefficient. The method is not limited by the unfavorable factors of the arc suppression coil, utilizes the compensation characteristics of the arc suppression coil in different frequency domains on the fault feeder line to form fault line selection, and has the advantages of strong anti-interference performance, high line selection accuracy, easiness in engineering realization and the like.
Description
Technical Field
The invention relates to the technical field of power system relay protection, in particular to a single-phase earth fault line selection method for a resonance grounding system.
Background
The long-term operation experience and operation practice result in that the neutral point of the power distribution network in China widely adopts a low-current grounding operation mode, which mainly comprises two modes of ungrounded mode and resonant grounding mode. The low current grounding operation mode has obvious advantages: when a single-phase earth fault occurs in the power distribution network, the fault current is similar to the load current in value due to the extremely high impedance of a fault loop, and the protection does not need to act immediately; the three-phase line voltage of the system still keeps symmetry, and the distribution network still has the ability of providing uninterrupted power supply for the load. Therefore, the operation rule allows the low-current grounding system to operate with a fault for 1-2 hours. However, the neutral point low current grounding operation mode has natural defects: under the condition of single-phase earth faults, the fault characteristics of the power distribution network are not obvious enough, and great difficulty is brought to fault detection and fault line selection.
In order to solve the problem of fault line selection of a low-current grounding system, experts and scholars at home and abroad develop extensive and deep research and obtain certain effect. The fault line selection methods disclosed in the prior art can be classified into injection signal analysis methods, steady-state component methods, transient component methods and the like. The injection signal analysis method has strong flexibility and high reliability; however, this method requires additional auxiliary electrical devices, and the method injects a specific electrical signal into the system, which is likely to cause interference with other devices. The steady-state component method has extremely high reliability in ungrounded systems, but its reliability tends to become poor when applied to resonant grounded systems. The transient component method is less influenced by the compensation effect of the arc suppression coil, is greatly concerned in recent years and becomes a research hotspot; however, the accuracy of the method in identifying the high-resistance ground fault is low, the method is easily interfered by other transient processes in the system, and the application effect in the actual engineering is not expected.
In summary, the existing fault line selection method is not complete. The problem of faulty line selection remains particularly troublesome in resonant grounded systems. Particularly, for a ground fault with a high transition resistance, the fault line selection accuracy of the existing method in actual engineering is often low, and the increasingly improved relay protection reliability requirement cannot be met.
Under the background, the problem of single-phase earth fault line selection of the resonance grounding system is not effectively solved, and the single-phase earth fault line selection method becomes a practical problem which puzzles field operation and maintenance personnel for a long time.
Disclosure of Invention
The invention aims to provide a single-phase earth fault line selection method of a resonance earthing system aiming at the defects of the existing fault line selection technology.
The invention relates to a single-phase earth fault line selection method of a resonance grounding system, which is realized by the following technical scheme:
step 1: the method comprises the following steps that a protection device is arranged at the head end of each feeder line on the same bus in a resonant grounding system, and the protection device monitors the feeder lines in real time; after the single-phase earth fault of the resonance earth system is judged, sampling is carried out on the zero-sequence current signal flowing through the head end of each feeder line to obtain a sampling data sequence
Wherein k is a serial number of a feeder line, and N is the total sampling times in a power frequency period;
step 2: from the data sequence
Extracting fundamental component information and attenuated direct current component information of the signal, wherein M is 0.5N; the extracted radicalsThe wave component information includes a fundamental amplitude
And fundamental phase angle theta(k)The extracted attenuated DC component information includes an initial attenuation amplitude D(k)And decay time constant τ(k)；
And step 3: according to the formula (1), filtering fundamental wave component and attenuation direct current component from zero sequence current signal to obtain data sequence
And 4, step 4: from the data sequence
Second harmonic amplitude of the extracted signal
Amplitude of third harmonic
And 5: amplitude of fundamental wave according to equation (2)
Second harmonic amplitude
And third harmonic amplitude
Carrying out normalization processing to obtain a data sequence after normalization processing
Wherein P is the total number of feeders;
step 6: for data sequence
Fitting is performed to obtain a characteristic coefficient { F(1),F(2),…,F(P)}；
And 7: for characteristic coefficient { F(1),F(2),…,F(P)Screening the elements in the power line, finding out the element with the largest numerical value, assigning the serial number of the element to a variable w, and finally judging that the w-th feeder line is the feeder line where the single-phase earth fault is located.
Preferably, wherein in step 6 the characteristic coefficients { F }(1),F(2),…,F(P)Obtaining according to the formula (3):
in the formula,
E(k)is the process coefficient.
The basic principle of the method of the invention is as follows:
the difficulty of implementing fault line selection for a resonant grounded system, as distinguished from an ungrounded system, is: when single-phase earth fault occurs, the arc suppression coil generates inductive zero-sequence current to compensate the capacitive fault current, and further weaken the fault characteristics. Therefore, the compensation function of the arc suppression coil increases the difficulty of fault line selection. However, from another perspective, the compensation of the crowbar coil is mainly reflected on the fault line and is more frequency sensitive. Therefore, the method of the invention is not limited by the unfavorable factors of the arc suppression coil, and the compensation characteristics of the arc suppression coil on the fault feeder line in different frequency domains are utilized to form the fault line selection.
The compensation characteristics of the arc suppression coil in different frequency domains are as follows:
the relation between the arc suppression coil and the compensated capacitance is shown as the following formula (4):
in the formula, L is the inductance value of the arc suppression coil, C is the capacitance value compensated by the arc suppression coil, the compensation function of the arc suppression coil can be represented, and omega is the angular frequency.
Substituting omega-2 pi f into formula (4) to obtain the product
Wherein f is the frequency.
As can be seen from equation (5), the compensation effect of the arc suppression coil is inversely proportional to the square of the frequency. As can be seen from the analysis of the fundamental wave (f is 50Hz), the second harmonic (f is 100Hz), and the third harmonic (f is 150Hz), the compensation of the second harmonic by the arc suppression coil is one fourth of the compensation of the fundamental wave, and the compensation of the third harmonic is one ninth of the compensation of the fundamental wave, as shown in fig. 1 of the drawings.
For a resonant grounding system, the zero sequence current measured by the healthy feeder line head end protection device is the capacitance current of the feeder line; the zero sequence current measured by the fault feeder line head end protection device is the sum of the arc suppression coil compensation current and all healthy feeder line capacitance currents. The above-mentioned compensation of the crowbar coil is therefore mainly present in the fault line. The fault line selection can be realized through the compensation characteristic of the arc suppression coil.
The compensation characteristic described above is reflected in relative values. The absolute value of the amplitude of each harmonic is measured by the protection device, not the relative value. Thus, the method of the present invention is directed to the fundamental amplitude according to equation (2)
Second harmonic amplitude
And third harmonic amplitude
Carrying out normalization processing to obtain a normalized data sequence
Wherein,
represents
The sum of all feeder line fundamental wave amplitude values
The ratio of (A) to (B);
represents
The sum of the amplitudes of the second harmonic of all the feeder lines
The ratio of (A) to (B);
represents
The sum of the third harmonic amplitudes of all the feeder lines
The ratio of (a) to (b).
Based on the compensation characteristics of the arc suppression coil, the data sequence can be obtained after analysis
Variations of (2)The trend will be approximately obeyed
The method uses a least square method to fit the characteristic coefficients, and characteristic coefficients { F ] are obtained according to a formula (3)(1),F(2),…,F(P)}. For a robust feeder line, the feeder line is,
showing a decreasing trend of change, the obtained F(k)The value of (a) is small and generally negative; in the case of a faulty feeder line,
showing an increasing trend of change, the obtained F(k)The value of (a) is positive and significantly greater than a sound feeder.
Based on the analysis, the method of the invention discriminates through { F }(1),F(2),…,F(P)Finding out the element with the maximum value from the values of the single-phase grounding fault, and determining the feeder where the single-phase grounding fault is located.
Herein, the pair
{F(1),F(2),…,F(P)The following brief description is made:
amplitude of fundamental wave
From the data sequence
Extracting. According to the formula (1), filtering fundamental wave component and attenuation direct current component from zero sequence current signal to obtain data sequence
Then, from the data sequence
Extract two of the signalSubharmonic amplitude
Amplitude of third harmonic
Coefficient of characteristics F(1),F(2),…,F(P)The value of the equation is obtained by a least square fitting method, and a specific calculation formula is shown in the formula (3).
The implementation steps of the fault line selection method of the invention are shown in figure 2 of the accompanying drawings.
The invention has the following advantages and effects: 1) the basic principle of the method is established on the basis of single-phase earth fault mechanism analysis, and the implementation method is practically adaptive to the actual fault processing of the power distribution network, so that the engineering implementation is facilitated. 2) The method has high fault line selection accuracy and is still reliable and effective under the condition of higher fault resistance. 3) The method of the invention can solve the characteristic coefficient by a least square fitting method, and has stronger anti-interference performance.
Drawings
Fig. 1 is a schematic diagram of compensation effects of arc suppression coils in different frequency domains.
Fig. 2 is a flow chart of the method for implementing fault line selection according to the present invention.
FIG. 3 is a diagram of a simulation model according to an embodiment of the present invention.
Fig. 4 is a waveform diagram of zero sequence current of the feeder line in the embodiment of the present invention.
Detailed Description
The present invention is described in further detail with reference to the following examples. It should be noted that the following example is only one practical implementation of the present invention, and is only used to more clearly illustrate the specific implementation of the method of the present invention, but the implementation of the present invention is not limited to this example.
Example (b):
fig. 3 is a diagram of a simulation model of single-phase grounding of the resonant grounding system of this embodiment. The system is a 10kV power distribution network system, and the system frequency is 50 Hz. The bus is connected with 4 feeder lines (feeder line 1-feeder line 4), and the length of the feeder lines is 6km, 7km, 4km and 7km in sequence. The arc suppression coil compensates the system capacitance through the grounding transformer. When t is 0.112s, a B-phase grounding fault occurs on the feeder 2 at a distance of 3.5km from the head end of the feeder.
According to the single-phase earth fault line selection method of the resonant grounding system, the fault line selection is implemented through the following steps:
step 1: the method comprises the following steps that a protection device is arranged at the head end of each feeder line on the same bus in the resonant grounding system, and the protection device monitors the feeder lines in real time; after the single-phase earth fault of the system is judged, sampling is carried out on the zero-sequence current signal flowing through the head end of each feeder line at the sampling frequency of 6000Hz to obtain a sampling data sequence of 1.5 power frequency periods after the fault
Wherein k is a serial number of a feeder line, and N is 120 which is the total sampling times in a power frequency period; the waveform of the collected current is shown in fig. 4;
step 2: from the data sequence
Extracting fundamental component information and attenuated direct current component information of the signal, wherein M is 0.5N 60; the extracted fundamental component information includes a fundamental amplitude
And fundamental phase angle theta(k)The extracted attenuated DC component information includes an initial attenuation amplitude D(k)And decay time constant τ(k)；
Specifically, the fundamental amplitude in this embodiment is
The fundamental phase angle (expressed in radians here) is θ(1)＝2.214，θ(2)＝2.154，θ(3)＝2.214，θ(4)＝2.212，
Initial attenuation amplitude of D(1)＝0.005，D(2)＝-3.171，D(3)＝0.004，D(4)＝0.009，
Decay time constant of τ(1)＝0.017，τ(2)＝0.032，τ(3)＝0.006，τ(4)＝0.013；
And step 3: according to the formula (1), filtering fundamental wave component and attenuation direct current component from zero sequence current signal to obtain data sequence
And 4, step 4: from the data sequence
Second harmonic amplitude of the extracted signal
Amplitude of third harmonic
Specifically, in the present embodiment, the second harmonic amplitude is
Third harmonic amplitude of
And 5: amplitude of fundamental wave according to equation (2)
Second harmonic amplitude
And third harmonic amplitude
Carrying out normalization processing to obtain a normalized data sequence
Specifically, in the present embodiment,
step 6: for data sequence
Fitting is performed, and a characteristic coefficient { F is obtained by a least square fitting formula shown in formula (3)(1),F(2),F(3),F(4)}＝{-0.023,0.182,-0.070,-0.088}；
And 7: for characteristic coefficient { F(1),F(2),F(3),F(4)Screening the elements in the data, and finding out the element with the largest numerical value as F(2)Then, the 2 nd feeder (i.e. feeder 2) is finally determined to be the feeder where the single-phase ground fault is located.
In the embodiment, the fault line selection result is consistent with the preset fault condition. The method can accurately find out the fault feeder line, and the effectiveness of the method is verified.
The above-mentioned embodiments are only preferred embodiments of the present invention, not all of them, but the protection scope of the present invention is not limited to the above-mentioned embodiments, and the specific protection scope is subject to the claims. It should be understood that various changes, substitutions and alterations in form and detail could be made herein without departing from the spirit and principles of the invention.
Claims (2)
1. A single-phase earth fault line selection method of a resonance grounding system is characterized by comprising the following steps:
step 1: the method comprises the following steps that a protection device is arranged at the head end of each feeder line on the same bus in a resonant grounding system, and the protection device monitors the feeder lines in real time; after the single-phase earth fault of the resonance earth system is judged, sampling is carried out on the zero-sequence current signal flowing through the head end of each feeder line to obtain a sampling data sequence
Wherein k is a serial number of a feeder line, and N is the total sampling times in a power frequency period;
step 2: from the data sequence
Extracting fundamental component information and attenuated direct current component information of the signal, wherein M is 0.5N; the extracted fundamental component information includes a fundamental amplitude
And fundamental phase angle theta(k)The extracted attenuated DC component information includes an initial attenuation amplitude D(k)And decay time constant τ(k)；
And step 3: according to the formula (1), filtering fundamental wave component and attenuation direct current component from zero sequence current signal to obtain data sequence
And 4, step 4: from the data sequence
Second harmonic amplitude of the extracted signal
Amplitude of third harmonic
And 5: amplitude of fundamental wave according to equation (2)
Second harmonic amplitude
And third harmonic amplitude
Carrying out normalization processing to obtain a data sequence after normalization processing
Wherein P is the total number of feeders;
step 6: for data sequence
Fitting is performed to obtain a characteristic coefficient { F(1),F(2),…,F(P)}；
And 7: for characteristic coefficient { F(1),F(2),…,F(P)Screening the elements in the test strip, and screening the elements,and finding out the element with the maximum numerical value, assigning the serial number of the element to a variable w, and finally judging that the w-th feeder is the feeder where the single-phase earth fault is located.
2. The single-phase earth fault line selection method of the resonant grounding system as claimed in claim 1, wherein the characteristic coefficient { F in the step 6(1),F(2),…,F(P)Obtaining according to the formula (3):
in the formula,
E(k)is the process coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910825474.2A CN110426604B (en) | 2019-09-03 | 2019-09-03 | Single-phase earth fault line selection method of resonance earthing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910825474.2A CN110426604B (en) | 2019-09-03 | 2019-09-03 | Single-phase earth fault line selection method of resonance earthing system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110426604A CN110426604A (en) | 2019-11-08 |
| CN110426604B true CN110426604B (en) | 2021-06-22 |
Family
ID=68418562
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910825474.2A Active CN110426604B (en) | 2019-09-03 | 2019-09-03 | Single-phase earth fault line selection method of resonance earthing system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110426604B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112305374B (en) * | 2020-10-22 | 2024-05-24 | 西安工程大学 | Single-phase earth fault line selection method for power distribution network |
| CN113644619B (en) * | 2021-10-14 | 2021-12-28 | 中国电力科学研究院有限公司 | Relay protection method and device based on multi-core processing chip |
| CN115343579B (en) * | 2022-10-20 | 2023-01-10 | 国网四川省电力公司电力科学研究院 | Power grid fault analysis method and device and electronic equipment |
| CN118348362B (en) * | 2024-06-18 | 2024-09-24 | 国网陕西省电力有限公司电力科学研究院 | Power distribution network high-resistance fault detection method based on fitting curve quadratic term coefficient |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002236139A (en) * | 2001-02-09 | 2002-08-23 | Nissin Electric Co Ltd | Fault locator |
| CN200976483Y (en) * | 2006-08-01 | 2007-11-14 | 沈阳工业大学 | Single-phase earth fault online wire-selecting protection equipment |
| CN100530884C (en) * | 2007-10-11 | 2009-08-19 | 天津大学 | Self-adaption route selection method for single-phase ground fault of power distribution network based on transient zero sequence current |
| CN107064729B (en) * | 2016-12-14 | 2019-09-17 | 国家电网公司 | Arc suppression coil earthing system single-phase grounding selecting method |
| CN107367670A (en) * | 2017-08-16 | 2017-11-21 | 杭州零尔电力科技有限公司 | A kind of fault line selection method for single-phase-to-ground fault based on quintuple harmonics electric current |
| CN110118913B (en) * | 2018-02-07 | 2022-04-05 | 华北电力大学（保定） | Arc suppression coil dispersion compensation power distribution network ground fault line selection method |
-
2019
- 2019-09-03 CN CN201910825474.2A patent/CN110426604B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110426604A (en) | 2019-11-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110426604B (en) | Single-phase earth fault line selection method of resonance earthing system | |
| Wang et al. | Location of single phase to ground faults in distribution networks based on synchronous transients energy analysis | |
| CN108957244B (en) | Single-phase earth fault line selection positioning method for distribution network main station | |
| Sumner et al. | Real time parameter estimation for power quality control and intelligent protection of grid-connected power electronic converters | |
| CN106463944A (en) | Method for detecting an open-phase condition of a transformer | |
| CN109444528B (en) | Transformer state monitoring system and method based on iron core grounding current | |
| CN110231552A (en) | Coal mine cable insulating monitoring selection method, injection circuit and related device | |
| CN111551821B (en) | Power distribution network ground fault identification method, device and equipment | |
| CN110161358A (en) | A kind of Earth design method and device | |
| CN102288873A (en) | Simulation-after-test method for identifying faults inside and outside direct current transmission line area based on flat wave inductance element property equation | |
| CN109782122A (en) | A kind of detection method of S Injection Signal | |
| CN104215867A (en) | Online recognition method for single-phase ground faults of low-voltage side of exciting transformer | |
| CN111381129B (en) | Ground fault line and type identification method and device based on ultralow frequency signal | |
| CN112255497A (en) | Fault line selection method based on fundamental frequency correlation and maximum correlation distance | |
| CN104090211B (en) | A kind of online test method of distribution line high resistance earthing fault | |
| CN103424627A (en) | Method for measuring zero-sequence impedance of parallel distribution network circuit at double ends | |
| CN111398730A (en) | Power distribution network based on passive injection direct current signal and fault identification method thereof | |
| CN110018401B (en) | Distribution line single-phase earth fault positioning method | |
| Sumner et al. | Improved power quality control and intelligent protection for grid connected power electronic converters, using real time parameter estimation | |
| Zhu et al. | High impedance grounding fault detection in resonance grounding system based on nonlinear distortion of zero-sequence current | |
| CN110231541B (en) | Method for carrying out inverse calculation on equivalent electrical parameters of system based on online monitoring of damped oscillation waves | |
| CN210690727U (en) | Step pulse injection circuit and related cable insulation monitoring line selection device | |
| Yongduan et al. | Earth fault protection using transient signals in non-solid earthed network | |
| Cui et al. | Experimental Research on Typical Single-Phase High Resistance Grounding Fault Detection Methods in Resonant Grounding Distribution System | |
| CN118501620B (en) | Power distribution network high-resistance fault identification method based on continuous filtering and kurtosis change rate |
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 | ||
| CB03 | Change of inventor or designer information |
Inventor after: Yang Haizhu Inventor after: Liu Penghui Inventor after: Liu Yonghui Inventor after: Jiang Zhaoyang Inventor before: Liu Penghui Inventor before: Liu Yonghui Inventor before: Yang Haizhu Inventor before: Jiang Zhaoyang |
|
| CB03 | Change of inventor or designer information |