CN113884764B - Early warning method of monitoring system for harmonic fluctuation of distribution cable - Google Patents
Early warning method of monitoring system for harmonic fluctuation of distribution cable Download PDFInfo
- Publication number
- CN113884764B CN113884764B CN202111286252.1A CN202111286252A CN113884764B CN 113884764 B CN113884764 B CN 113884764B CN 202111286252 A CN202111286252 A CN 202111286252A CN 113884764 B CN113884764 B CN 113884764B
- Authority
- CN
- China
- Prior art keywords
- fault
- considered
- harmonic
- correlation
- rho
- 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
- 238000009826 distribution Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000012544 monitoring process Methods 0.000 title claims abstract description 15
- 238000012545 processing Methods 0.000 claims abstract description 18
- 238000005070 sampling Methods 0.000 claims abstract description 16
- 230000003750 conditioning effect Effects 0.000 claims abstract description 12
- 238000004458 analytical method Methods 0.000 claims abstract description 10
- 238000012806 monitoring device Methods 0.000 claims abstract description 9
- 238000004891 communication Methods 0.000 claims abstract description 7
- 238000004364 calculation method Methods 0.000 claims description 9
- 238000013500 data storage Methods 0.000 claims description 3
- 238000009413 insulation Methods 0.000 abstract description 6
- 230000007547 defect Effects 0.000 abstract description 4
- 239000000463 material Substances 0.000 description 2
- 206010000369 Accident Diseases 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/16—Spectrum analysis; Fourier analysis
Landscapes
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
The invention relates to a monitoring system for harmonic fluctuation of a distribution cable, which comprises a high-precision current transformer, a distribution cable distributed monitoring device and a background analysis server, wherein the high-precision current transformer is connected with the distribution cable distributed monitoring device; the distribution cable distributed monitoring device comprises an analog sensing and conditioning module; the high-precision current transformer is connected with an analog quantity sensing and conditioning module; the analog sensing and conditioning module is connected with the high-frequency sampling module; the high-frequency sampling module is connected with the core processing unit; the core processing unit is communicated with the background analysis server through the communication module. The invention also discloses an early warning method of the monitoring system for harmonic fluctuation of the distribution cable. According to the invention, the harmonic signals formed by the discharge phenomenon of the insulation defects of the cable line are collected, the electric quantity harmonic characteristics of the distribution cable are captured and analyzed, and the cable state is evaluated and early-warned by comparing the typical data of the previous or historical record of the line, so that the latent faults can be found early, and the power failure loss caused by the faults is reduced.
Description
Technical Field
The invention relates to the technical field of monitoring of the running state of a distribution cable, in particular to an early warning method of a monitoring system for harmonic fluctuation of the distribution cable.
Background
With the acceleration of the urban process in China, the coverage rate and the asset scale of the power cable are increasing at unprecedented speeds. In order to meet the power supply demand, the proportion of power cables in the urban power grid is increasing. Although the power cable operates more reliably than overhead lines, the power cable may fail during operation due to various factors. For example, in power plants and transformer substations, cable bridges, cable tunnels, cable interlayers, cable trenches, cable shafts, switchgears, transformers, resistor banks and other power equipment are heated in long-term high voltage to cause fire, and through fire investigation and research for many years, most of fire accidents are caused by overhigh temperature, and particularly, the loss caused by the fire of the cable tunnels is the largest.
The main causes of the failure can be roughly summarized as follows: mechanical damage, insulation wetting, insulation aging deterioration, overvoltage, poor design and manufacturing processes, material defects, corrosion of the protective layer, loss of insulation of the cable and the like. Because the power cable has thick insulating layers and is buried underground, once the power cable fails, the power cable is difficult to find, a large amount of manpower and material resources are often required to be spent, and extra power failure loss can be caused due to overlong repair time, so that the workload of operation management, detection maintenance and the like of the power cable is increased.
The current monitoring system is mainly aimed at single-core power transmission cables of 110kV and above, and the medium-low voltage distribution cables currently lack effective real-time on-line monitoring means and methods.
Disclosure of Invention
The invention aims to provide an early warning method of a power distribution cable harmonic fluctuation monitoring system, which is used for evaluating and early warning the cable state by monitoring the electric quantity harmonic characteristics of a power distribution cable in real time and comparing typical data of a front or historical record of a line.
In order to achieve the above purpose, the present invention adopts the following technical scheme: an early warning method of a monitoring system for harmonic fluctuation of a distribution cable, the method comprises the following sequential steps:
(1) Sampling 4 voltages and 4 currents at high frequency and storing the sampled 4 voltages and the 4 currents as standard com format data;
(2) Calculating effective value phase voltage, phase current and zero sequence voltage zero sequence current, and setting a starting threshold;
(3) Calculating and recording the content of each harmonic wave and the total harmonic distortion rate by taking 5 cycles as a time window;
(4) After the voltage and current or the total harmonic distortion rate or the content of each subharmonic reach the starting threshold, storing 100 cycles before starting, recovering the data in 5 cycles after recovering, and calling the recording data at the last starting time to enter the step (5);
(5) The method comprises the steps of calling wave recording data during faults and harmonic distortion rate change conditions during two faults, comparing, and evaluating and early warning cable states;
(6) After all data are stored, harmonic information showing close correlation is uploaded, and early warning information is provided;
The monitoring system comprises a high-precision current transformer, a distribution cable distributed monitoring device and a background analysis server; the distributed monitoring device for the distribution cable comprises an analog sensing conditioning module, a high-frequency sampling module, a communication module, a core processing unit, a power module and a shell; the output end of the high-precision current transformer is connected with the input end of the analog quantity sensing conditioning module; the output end of the analog sensing conditioning module is connected with the input end of the high-frequency sampling module; the output end of the high-frequency sampling module is connected with the input end of the core processing unit; the core processing unit is communicated with the background analysis server through the communication module; the core processing unit is integrated with a microprocessor chip with a distribution cable harmonic fluctuation early warning algorithm;
the step (2) specifically refers to: in a power frequency period, the calculation formula of the true effective value U T of the phase voltage is as follows:
Comparing the voltage amplitude of each cycle with a fault starting threshold by taking the cycle as a unit;
The fault starting threshold of the phase voltage and the phase current is 2 times of the true effective value; calculating zero sequence current and zero sequence voltage by using 3 half waves or 30ms sampling point data;
after the fault is started, determining a fault starting point: from the previous cycle of the fault starting, comparing voltage instantaneous values in turn, and determining a point that the amplitude value of the first instantaneous value, namely the absolute value of the instantaneous value, is 1.4 times greater than the fault starting threshold as a fault starting point; when the voltage of 2 or more continuous cycles exceeds the fault starting threshold, confirming the earth fault, otherwise, considering disturbance; the end of the disturbance is the second cycle after the fault is started; that is, if the voltage exceeds the fail-over threshold from the third cycle, a new fault is considered.
The step (3) specifically refers to: the content ratio HR of each harmonic and the total harmonic distortion ratio THD are set to 2 to 63 harmonics; if the total harmonic distortion is more than 4%, the odd order is more than 3.2%, the even order is more than 1.6%, and one of the three is satisfied, then the method is started, and recording and data storage are carried out.
The step (5) specifically comprises the following steps:
(5a) And calling current data to perform similarity calculation, wherein the calculation formula is as follows:
Wherein ρ is a value between-1 and +1;
(5b) If the voltage and current reach the recording data of the fault starting threshold for 2 times before and after, if the absolute value of rho is larger than 0.7, the fault of the two times before and after is considered to be the same type of fault, and if the absolute value of rho is smaller than or equal to 0.7, the fault of the two times before and after is considered to be different types of faults;
When the absolute value of rho is larger than 0.7, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.7, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5c) If the front and back 2 times are recorded data with the harmonic distortion rate reaching a fault starting threshold, if the absolute value of rho is larger than 0.3, the front and back two faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.3, the front and back two faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.3, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5d) If the front and back 2 times are not the same type of fault starting threshold, if the absolute value of rho is larger than 0.5, the front and back two times of faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.5, the front and back two times of faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.5, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5e) The frequency of the correlation of each subharmonic is 1 is accumulated, and if the correlation of a subharmonic exceeds 10% of the total accumulated frequency of each subharmonic, the subharmonic is considered to have close correlation with the cable fault.
According to the technical scheme, the beneficial effects of the invention are as follows: according to the invention, the harmonic signals formed by the discharge phenomenon of the insulation defects of the cable line are collected, the electric quantity harmonic characteristics of the distribution cable are captured and analyzed, and the cable state is evaluated and early-warned by comparing the typical data of the previous or historical record of the line, so that the latent faults can be found early, and the power failure loss caused by the faults is reduced.
Drawings
FIG. 1 is a flow chart of a method for early warning of harmonic fluctuation of a distribution cable;
FIG. 2 is a flowchart of a harmonic fluctuation correlation determination method according to the present invention;
fig. 3 is a block diagram of the system architecture of the present invention.
Detailed Description
As shown in fig. 3, a monitoring system for harmonic fluctuation of a distribution cable comprises a high-precision current transformer, a distribution cable distributed monitoring device and a background analysis server; the distributed monitoring device for the distribution cable comprises an analog sensing conditioning module, a high-frequency sampling module, a communication module, a core processing unit, a power module and a shell; the output end of the high-precision current transformer is connected with the input end of the analog quantity sensing conditioning module; the output end of the analog sensing conditioning module is connected with the input end of the high-frequency sampling module; the output end of the high-frequency sampling module is connected with the input end of the core processing unit; the core processing unit is communicated with the background analysis server through the communication module; and the core processing unit is integrated with a microprocessor chip with a distribution cable harmonic fluctuation early warning algorithm.
As shown in fig. 1 and 2, the method comprises the following steps in sequence:
(1) Sampling 4 voltages and 4 currents at high frequency and storing the sampled 4 voltages and the 4 currents as standard com format data;
(2) Calculating effective value phase voltage, phase current and zero sequence voltage zero sequence current, and setting a starting threshold;
(3) Calculating and recording the content of each harmonic wave and the total harmonic distortion rate by taking 5 cycles as a time window;
(4) After the voltage and current or the total harmonic distortion rate or the content of each subharmonic reach the starting threshold, storing 100 cycles before starting, recovering the data in 5 cycles after recovering, and calling the recording data at the last starting time to enter the step (5);
(5) The method comprises the steps of calling wave recording data during faults and harmonic distortion rate change conditions during two faults, comparing, and evaluating and early warning cable states;
(6) After all the data are stored, the harmonic information showing close correlation is uploaded, and early warning information is provided.
The step (2) specifically refers to: in a power frequency period, the calculation formula of the true effective value U T of the phase voltage is as follows:
Comparing the voltage amplitude of each cycle with a fault starting threshold by taking the cycle as a unit;
The fault starting threshold of the phase voltage and the phase current is 2 times of the true effective value; calculating zero sequence current and zero sequence voltage by using 3 half waves or 30ms sampling point data;
after the fault is started, determining a fault starting point: from the previous cycle of the fault starting, comparing voltage instantaneous values in turn, and determining a point that the amplitude value of the first instantaneous value, namely the absolute value of the instantaneous value, is 1.4 times greater than the fault starting threshold as a fault starting point; when the voltage of 2 or more continuous cycles exceeds the fault starting threshold, confirming the earth fault, otherwise, considering disturbance; the end of the disturbance is the second cycle after the fault is started; that is, if the voltage exceeds the fail-over threshold from the third cycle, a new fault is considered.
The step (3) specifically refers to: the content ratio HR of each harmonic and the total harmonic distortion ratio THD are set to 2 to 63 harmonics; if the total harmonic distortion is more than 4%, the odd order is more than 3.2%, the even order is more than 1.6%, and one of the three is satisfied, then the method is started, and recording and data storage are carried out.
The step (5) specifically comprises the following steps:
(5a) And calling current data to perform similarity calculation, wherein the calculation formula is as follows:
Wherein ρ is a value between-1 and +1;
(5b) If the voltage and current reach the recording data of the fault starting threshold for 2 times before and after, if the absolute value of rho is larger than 0.7, the fault of the two times before and after is considered to be the same type of fault, and if the absolute value of rho is smaller than or equal to 0.7, the fault of the two times before and after is considered to be different types of faults;
When the absolute value of rho is larger than 0.7, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.7, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5c) If the front and back 2 times are recorded data with the harmonic distortion rate reaching a fault starting threshold, if the absolute value of rho is larger than 0.3, the front and back two faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.3, the front and back two faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.3, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5d) If the front and back 2 times are not the same type of fault starting threshold, if the absolute value of rho is larger than 0.5, the front and back two times of faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.5, the front and back two times of faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.5, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5e) The frequency of the correlation of each subharmonic is 1 is accumulated, and if the correlation of a subharmonic exceeds 10% of the total accumulated frequency of each subharmonic, the subharmonic is considered to have close correlation with the cable fault.
In summary, the invention captures and analyzes the electrical harmonic characteristics of the distribution cable by collecting the harmonic signals formed by the discharge phenomenon of the insulation defect of the cable line, and evaluates and pre-warns the cable state by comparing the typical data of the prior or historical record of the line, thereby being capable of early finding the hidden fault and reducing the power failure loss caused by the fault.
Claims (3)
1. A warning method of a monitoring system for harmonic fluctuation of a distribution cable is characterized by comprising the following steps of: the method comprises the following steps in sequence:
(1) The high-precision current transformer and the voltage transformer sample three-phase voltage, three-phase current, zero-sequence voltage and zero-sequence current of the cable to be tested at high frequency;
(2) The core processing unit calculates effective value phase voltage, phase current, zero sequence voltage and zero sequence current, and sets a fault starting threshold;
(3) Taking 5 cycles as a time window, the core processing unit calculates and records the content of each harmonic and the total harmonic distortion rate;
(4) Storing 100 cycles before starting after one of the voltage and current, the total harmonic distortion rate and the content of each subharmonic reaches a fault starting threshold, recovering the data in 5 cycles after the starting, and calling the recording data at the time of the last starting to enter the step (5);
(5) The core processing unit is used for calling the fault time recording data and the harmonic distortion rate change condition during the two faults, comparing, and evaluating and early warning the cable state;
(6) After the core processing unit stores all data, harmonic information showing close correlation is uploaded to a background analysis server, and early warning is provided by the background analysis server;
the monitoring system comprises a high-precision current transformer, a voltage transformer, a distribution cable distributed monitoring device and a background analysis server; the distributed monitoring device for the distribution cable comprises an analog sensing conditioning module, a high-frequency sampling module, a communication module, a core processing unit, a power module and a shell; the output ends of the high-precision current transformer and the voltage transformer are connected to the input end of the analog sensing conditioning module; the output end of the analog sensing conditioning module is connected with the input end of the high-frequency sampling module; the output end of the high-frequency sampling module is connected with the input end of the core processing unit; the core processing unit is communicated with the background analysis server through the communication module; the core processing unit is integrated with a microprocessor chip with a distribution cable harmonic fluctuation early warning algorithm;
the step (2) specifically refers to: in a power frequency period, the calculation formula of the true effective value U T of the phase voltage is as follows:
Comparing the voltage amplitude of each cycle with a fault starting threshold by taking the cycle as a unit;
The fault starting threshold of the phase voltage and the phase current is 2 times of the true effective value; calculating zero sequence current and zero sequence voltage by using 3 half waves or 30ms sampling point data;
after the fault is started, determining a fault starting point: from the previous cycle of the fault starting, comparing voltage instantaneous values in turn, and determining a point that the amplitude value of the first instantaneous value, namely the absolute value of the instantaneous value, is 1.4 times greater than the fault starting threshold as a fault starting point; when the voltage of 2 or more continuous cycles exceeds the fault starting threshold, confirming the earth fault, otherwise, considering disturbance; the end of the disturbance is the second cycle after the fault is started; that is, if the voltage exceeds the fail-over threshold from the third cycle, a new fault is considered.
2. The method of claim 1, wherein: the step (3) specifically refers to: the content ratio HR of each harmonic and the total harmonic distortion ratio THD are set to 2 to 63 harmonics; if the total harmonic distortion is more than 4%, the odd order is more than 3.2%, the even order is more than 1.6%, and one of the three is satisfied, then the method is started, and recording and data storage are carried out.
3. The method of claim 1, wherein: the step (5) specifically comprises the following steps:
(5a) And calling current data to perform similarity calculation, wherein the calculation formula is as follows:
Wherein ρ is a value between-1 and +1;
(5b) If the voltage and current reach the recording data of the fault starting threshold for 2 times before and after, if the absolute value of rho is larger than 0.7, the fault of the two times before and after is considered to be the same type of fault, and if the absolute value of rho is smaller than or equal to 0.7, the fault of the two times before and after is considered to be different types of faults;
When the absolute value of rho is larger than 0.7, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.7, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5c) If the front and back 2 times are recorded data with the harmonic distortion rate reaching a fault starting threshold, if the absolute value of rho is larger than 0.3, the front and back two faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.3, the front and back two faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.3, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5d) If the front and back 2 times are not the same type of fault starting threshold, if the absolute value of rho is larger than 0.5, the front and back two times of faults are considered to be the same type of faults, and if the absolute value of rho is smaller than or equal to 0.5, the front and back two times of faults are considered to be different types of faults;
When the absolute value of rho is larger than 0.5, the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is more than or equal to 20%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
The absolute value of rho is smaller than or equal to 0.3, and the content of each subharmonic is called and compared; if the content change rate of a certain harmonic is greater than or equal to 50%, the correlation between the certain harmonic and the fault is considered to be 1; otherwise, the correlation is considered to be 0;
(5e) The frequency of the correlation of each subharmonic is 1 is accumulated, and if the correlation of a subharmonic exceeds 10% of the total accumulated frequency of each subharmonic, the subharmonic is considered to have close correlation with the cable fault.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111139036 | 2021-09-27 | ||
| CN2021111390364 | 2021-09-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113884764A CN113884764A (en) | 2022-01-04 |
| CN113884764B true CN113884764B (en) | 2024-05-03 |
Family
ID=79015309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111286252.1A Active CN113884764B (en) | 2021-09-27 | 2021-11-02 | Early warning method of monitoring system for harmonic fluctuation of distribution cable |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113884764B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0698457A (en) * | 1991-11-28 | 1994-04-08 | Kansai Electric Power Co Inc:The | Cause judgment method of ground fault of high-voltage distribution line |
| KR20030073347A (en) * | 2002-03-11 | 2003-09-19 | 학교법인 성균관대학 | Method for condition monitoring of power cable using harmonics and system thereof |
| CN106443292A (en) * | 2016-01-21 | 2017-02-22 | 张家港智电电工高技术研究所有限公司 | Overhead line single-phase earth fault detection method based on zero sequence current measurement |
| CN108957132A (en) * | 2018-08-31 | 2018-12-07 | 国网江苏省电力有限公司徐州供电分公司 | A kind of Measurement of Harmonics in Power System device and its detection method based on synchronized sampling complete cycle |
-
2021
- 2021-11-02 CN CN202111286252.1A patent/CN113884764B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0698457A (en) * | 1991-11-28 | 1994-04-08 | Kansai Electric Power Co Inc:The | Cause judgment method of ground fault of high-voltage distribution line |
| KR20030073347A (en) * | 2002-03-11 | 2003-09-19 | 학교법인 성균관대학 | Method for condition monitoring of power cable using harmonics and system thereof |
| CN106443292A (en) * | 2016-01-21 | 2017-02-22 | 张家港智电电工高技术研究所有限公司 | Overhead line single-phase earth fault detection method based on zero sequence current measurement |
| CN108957132A (en) * | 2018-08-31 | 2018-12-07 | 国网江苏省电力有限公司徐州供电分公司 | A kind of Measurement of Harmonics in Power System device and its detection method based on synchronized sampling complete cycle |
Non-Patent Citations (2)
| Title |
|---|
| 一种新型故障录波装置的构成原理及设计;蔡舒平, 张保会, 薛岩；;电气传动自动化;20030630(第03期);全文 * |
| 配电***谐波抑制治理设计;马益平;陈士华;方健美;;电气应用;20180520(第10期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113884764A (en) | 2022-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103728538B (en) | A kind of ground fault line selecting method of small current neutral grounding system | |
| CN106950459B (en) | Distributed single-phase earth fault judgment method | |
| WO2022099795A1 (en) | Detection method for detecting small-current single-phase ground fault in 10 kv distribution network | |
| CN110514954B (en) | Power line fault diagnosis method and system based on PMU data | |
| CN112381668B (en) | Information extraction method for power grid faults | |
| CN102087316B (en) | Online monitoring method for short-circuit impedance of V/X connection traction transformer | |
| CN1349103A (en) | Judgement method of one-phase earthing failure in electric distribution network | |
| CN117269700B (en) | Voltage transformer insulation defect diagnosis method based on fault wave recording information | |
| CN113884764B (en) | Early warning method of monitoring system for harmonic fluctuation of distribution cable | |
| CN105866592A (en) | System and method for acquiring dynamic reactive power compensation response waveforms | |
| CN109324268B (en) | Power distribution network early fault detection method and device based on Bayesian inference | |
| CN116840614A (en) | Cable line defect sensing and early warning method based on harmonic fluctuation characteristics | |
| CN114911752A (en) | Method for archiving three-terminal fault data of T-connection line | |
| CN111025095B (en) | XLPE cable terminal insulation reliability intelligent and rapid assessment method | |
| CN114355004A (en) | Medium-voltage anti-electricity-stealing analysis method based on coding correlation | |
| CN110231541B (en) | Method for carrying out inverse calculation on equivalent electrical parameters of system based on online monitoring of damped oscillation waves | |
| CN112986858A (en) | Ground fault judgment method based on zero sequence wavelet decomposition calculation | |
| CN114142442A (en) | Direct-current transmission line protection method and system | |
| CN114062838B (en) | DC wiring fault positioning method and device and medium-voltage DC power distribution equipment | |
| CN112505490A (en) | Power distribution network single-phase earth fault line selection method based on mutual difference absolute value sum | |
| CN113376553B (en) | Intelligent screening method and system for three-phase four-wire metering string current loop wiring | |
| CN113919853B (en) | Low-voltage user electricity stealing identification method based on edge-to-edge fusion | |
| CN113093085B (en) | Secondary circuit fault detection method and device for station domain current transformer | |
| CN113671239B (en) | Intelligent overvoltage identification method, device and system for high-voltage switch PT cabinet | |
| CN113899986B (en) | Single-phase ground fault incremental phase selection protection method and device |
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 |