CN109387731B - High-resistance grounding fault identification method based on wavelet analysis and amplitude comparison - Google Patents
High-resistance grounding fault identification method based on wavelet analysis and amplitude comparison Download PDFInfo
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- CN109387731B CN109387731B CN201811573464.6A CN201811573464A CN109387731B CN 109387731 B CN109387731 B CN 109387731B CN 201811573464 A CN201811573464 A CN 201811573464A CN 109387731 B CN109387731 B CN 109387731B
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- 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
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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- 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
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- 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
Abstract
The application discloses a high-resistance grounding fault identification method based on wavelet analysis and amplitude comparison, which comprises the following steps: acquiring a corresponding three-phase voltage value of the low-voltage capacitor; calculating to obtain an actual three-phase voltage value and a corresponding voltage waveform on the power transmission line by utilizing a voltage division ratio according to the three-phase voltage value of the low-voltage capacitor; carrying out six-layer decomposition on the voltage waveform by using a db5 wavelet to obtain a first-layer high-frequency coefficient and a second-layer high-frequency coefficient; judging whether a first type discontinuity exists according to the first layer high-frequency coefficient and the second layer high-frequency coefficient; if the first type of discontinuity point exists, determining that the transmission line has a fault; calculating to obtain a voltage coefficient according to the amplitude of the actual three-phase voltage value on the power transmission line; and if the voltage coefficient is smaller than the preset threshold value, the transmission line fault is a high-resistance grounding fault. The method can find a smaller abrupt change amount, and the high-resistance grounding fault can be identified more accurately.
Description
Technical Field
The application relates to the technical field of ground fault identification, in particular to a high-resistance ground fault identification method based on wavelet analysis and amplitude comparison.
Background
A large part of the power distribution line faults are single-phase earth faults and other faults caused by single-phase faults. Under the low-current grounding operation mode, the single-phase grounding fault current ratio is small, and the system can continue to operate for a certain time after a fault occurs, so the low-current grounding operation mode obviously improves the reliability of power supply, and meanwhile, the interference to a communication system is small. However, if the system equipment is operated with a fault for a long time, especially when intermittent arc grounding high-resistance fault occurs on the line, overvoltage generated by the fault easily causes new grounding point of the system equipment, so that the accident is further enlarged and further short-circuit fault is caused. The traditional relay protection measures can accurately detect and protect common single-phase earth faults, low-resistance earth faults and the like, but because a large abrupt change cannot be generated in the high-resistance faults, the traditional method is easy to generate the missing judgment of the faults, and further accidents are caused.
Disclosure of Invention
The application provides a high-resistance grounding fault identification method based on wavelet analysis and amplitude comparison, and aims to solve the problem that due to the fact that a large abrupt change cannot be generated during high-resistance fault, missed judgment of faults is prone to being generated in a traditional method, and further accidents are caused.
The application provides a high-resistance grounding fault identification method based on wavelet analysis and amplitude comparison, which comprises the following steps:
acquiring a three-phase voltage value of a low-voltage capacitor;
calculating to obtain an actual three-phase voltage value and a corresponding voltage waveform on the power transmission line by utilizing a voltage division ratio according to the three-phase voltage value of the low-voltage capacitor;
carrying out six-layer decomposition on the voltage waveform by using a db5 wavelet to obtain a first-layer high-frequency coefficient and a second-layer high-frequency coefficient;
judging whether a first type discontinuity exists according to the first layer high-frequency coefficient and the second layer high-frequency coefficient; if the first type of discontinuity point exists, determining that the transmission line has a fault; if there is no discontinuity of the first type, jumping to the step of db5 wavelet decomposition;
calculating to obtain a voltage coefficient by using a preset formula according to the amplitude of the actual three-phase voltage value on the power transmission line;
if the voltage coefficient is smaller than a preset threshold value, the transmission line fault is a high-resistance grounding fault; and if the voltage coefficient is larger than or equal to a preset threshold value, jumping to the step of db5 wavelet decomposition.
According to the technical scheme, the high-resistance grounding fault identification method based on wavelet analysis and amplitude comparison is provided, the wavelet analysis is utilized to carry out mutation detection on the acquired voltage signals, and when mutation is detected, amplitude comparison is carried out to determine whether the voltage signals are high-voltage grounding faults or not. Therefore, the method can find a smaller sudden change amount, and the high-resistance grounding fault can be identified more accurately.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without any creative effort.
Fig. 1 is a flowchart of a high-resistance ground fault identification method based on wavelet analysis and amplitude comparison according to the present application.
Detailed Description
Referring to fig. 1, the present application provides a high-resistance ground fault identification method based on wavelet analysis and amplitude comparison, including the following steps:
step 11: and acquiring the three-phase voltage value of the low-voltage capacitor.
The three-phase voltage value of the low-voltage capacitor can be measured by a ceramic capacitor sensor on the ceramic capacitor core and is transmitted to a signal detection system through a wireless network by an acquisition circuit.
Step 12: and calculating the actual three-phase voltage value and the corresponding voltage waveform on the power transmission line by utilizing a voltage division ratio according to the three-phase voltage value of the low-voltage capacitor.
Step 13: and carrying out six-layer decomposition on the voltage waveform by using a db5 wavelet to obtain a first-layer high-frequency coefficient and a second-layer high-frequency coefficient.
Step 14: judging whether a first type discontinuity exists according to the first layer high-frequency coefficient and the second layer high-frequency coefficient; if there is a discontinuity of the first type, step 15 is performed; if there is no discontinuity of the first type, it jumps to step 13.
The specific steps for determining the first type of discontinuity point are as follows:
(1) and selecting the maximum value of the first layer high-frequency coefficient and the maximum value of the second layer high-frequency coefficient.
(2) A first type discontinuity exists if the maximum of the first layer high frequency coefficients is greater than 0.1 and the maximum of the second layer high frequency coefficients is greater than 0.1.
Step 15: and determining the transmission line fault.
Step 16: and calculating to obtain a voltage coefficient by using a preset formula according to the amplitude of the actual three-phase voltage value on the power transmission line.
Preset formula as
Wherein ku is a voltage coefficient; ua is the amplitude of the phase voltage A; ub is the amplitude of the phase voltage B; uc is the amplitude of the C-phase voltage;
is the grid phase voltage.
And step 17: and if the voltage coefficient is smaller than the preset threshold value, the transmission line fault is a high-resistance grounding fault.
Step 18: and if the voltage coefficient is greater than or equal to a preset threshold value, jumping to the step 13. The value range of the preset threshold is 0-1.
According to the technical scheme, the high-resistance grounding fault identification method based on wavelet analysis and amplitude comparison is provided, the wavelet analysis is utilized to carry out mutation detection on the acquired voltage signals, and when mutation is detected, amplitude comparison is carried out to determine whether the voltage signals are high-voltage grounding faults or not. Therefore, the method can find a smaller sudden change amount, and the high-resistance grounding fault can be identified more accurately.
Claims (3)
1. A high-resistance ground fault identification method based on wavelet analysis and amplitude comparison is characterized by comprising the following steps:
acquiring a three-phase voltage value of a low-voltage capacitor;
calculating to obtain an actual three-phase voltage value and a corresponding voltage waveform on the power transmission line by utilizing a voltage division ratio according to the three-phase voltage value of the low-voltage capacitor;
carrying out six-layer decomposition on the voltage waveform by using a db5 wavelet to obtain a first-layer high-frequency coefficient and a second-layer high-frequency coefficient;
judging whether a first type discontinuity exists according to the first layer high-frequency coefficient and the second layer high-frequency coefficient; the specific steps for determining the first type of discontinuity point are as follows: selecting the maximum value of the first layer of high-frequency coefficients and the maximum value of the second layer of high-frequency coefficients; if the maximum value of the first-layer high-frequency coefficients is greater than 0.1 and the maximum value of the second-layer high-frequency coefficients is greater than 0.1, a first-type discontinuity exists;
if the first type of discontinuity point exists, determining that the transmission line has a fault; if there is no discontinuity of the first type, jumping to the step of db5 wavelet decomposition;
calculating to obtain a voltage coefficient by using a preset formula according to the amplitude of the actual three-phase voltage value on the power transmission line;
if the voltage coefficient is smaller than a preset threshold value, the transmission line fault is a high-resistance grounding fault; and if the voltage coefficient is larger than or equal to a preset threshold value, jumping to the step of db5 wavelet decomposition.
2. The method of claim 1, wherein the predetermined formula is
Wherein ku is a voltage coefficient; ua is the amplitude of the phase voltage A; ub is the amplitude of the phase voltage B; uc is the amplitude of the C-phase voltage; and U phi is the phase voltage of the power grid.
3. The method of claim 1, wherein the predetermined threshold value ranges from 0 to 1.
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| EP3713029A1 (en) * | 2019-03-18 | 2020-09-23 | Siemens Aktiengesellschaft | Locating an earth fault in a dc network with multiple load zones |
| CN113030648B (en) * | 2021-03-19 | 2023-01-10 | 国网河北省电力有限公司邢台供电分公司 | Power cable fault point position determining method and device and terminal equipment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102185290A (en) * | 2011-03-03 | 2011-09-14 | 清华大学 | Self-recovering method of single-phase earth faults |
| CN103364684A (en) * | 2013-07-12 | 2013-10-23 | 桐乡市供电局 | Fault line selection method based on wavelet analysis |
| CN104865499A (en) * | 2015-05-11 | 2015-08-26 | 昆明理工大学 | Super-high voltage direct-current power transmission line region internal and external fault identification method |
| CN106597227A (en) * | 2016-12-30 | 2017-04-26 | 北京鼎科远图科技有限公司 | Method and device for determining single-phase-to-ground fault based on global wavelet coefficient balance method |
| CN107589342A (en) * | 2017-09-04 | 2018-01-16 | 云南电网有限责任公司电力科学研究院 | A kind of one-phase earthing failure in electric distribution network localization method and system |
| CN107907279A (en) * | 2017-11-20 | 2018-04-13 | 中国石油大学(华东) | Multiphase flow pipeline leakage acoustic signals analysis method based on wavelet coefficient amplitude |
| CN108226709A (en) * | 2017-12-20 | 2018-06-29 | 南京威尔泰电气工程有限公司 | A kind of small current neutral grounding faulty line selection method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018627B (en) * | 2012-10-25 | 2014-12-31 | 福建省电力有限公司 | Adaptive fault type fault line detection method for non-effectively earthed system |
| WO2016205558A1 (en) * | 2015-06-18 | 2016-12-22 | Ultradian Diagnostics Llc | Methods and devices for determining metabolic states |
-
2018
- 2018-12-21 CN CN201811573464.6A patent/CN109387731B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102185290A (en) * | 2011-03-03 | 2011-09-14 | 清华大学 | Self-recovering method of single-phase earth faults |
| CN103364684A (en) * | 2013-07-12 | 2013-10-23 | 桐乡市供电局 | Fault line selection method based on wavelet analysis |
| CN104865499A (en) * | 2015-05-11 | 2015-08-26 | 昆明理工大学 | Super-high voltage direct-current power transmission line region internal and external fault identification method |
| CN106597227A (en) * | 2016-12-30 | 2017-04-26 | 北京鼎科远图科技有限公司 | Method and device for determining single-phase-to-ground fault based on global wavelet coefficient balance method |
| CN107589342A (en) * | 2017-09-04 | 2018-01-16 | 云南电网有限责任公司电力科学研究院 | A kind of one-phase earthing failure in electric distribution network localization method and system |
| CN107907279A (en) * | 2017-11-20 | 2018-04-13 | 中国石油大学(华东) | Multiphase flow pipeline leakage acoustic signals analysis method based on wavelet coefficient amplitude |
| CN108226709A (en) * | 2017-12-20 | 2018-06-29 | 南京威尔泰电气工程有限公司 | A kind of small current neutral grounding faulty line selection method |
Non-Patent Citations (3)
| Title |
|---|
| Fault Line Selection Method of Small Current to Ground System Based on Atomic Sparse Decomposition and Extreme Learning Machine;XiaoweiWang等;《Journal of Sensors》;20151231;全文 * |
| 基于连续小波变换的变压器绕组变形故障类型检测;钱国超;《高电压技术》;20170630;第43卷(第6期);全文 * |
| 电缆网故障选线方法的研究;苑舜等;《高压电器》;20110131;第47卷(第1期);全文 * |
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