CN110579669A - small current ground fault detection system and method based on zero sequence component analysis - Google Patents
small current ground fault detection system and method based on zero sequence component analysis Download PDFInfo
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Abstract
the invention provides a small current ground fault detection system based on zero sequence component analysis, which comprises a current sensor, a voltage sensor, a signal conditioning unit, an A/D conversion unit, a control processing unit, a key input unit, a display unit, a storage unit, an alarm unit and a communication unit, wherein the A/D conversion unit is used for converting a current signal into a voltage signal; the small current ground fault detection system preliminarily judges whether the zero sequence voltage signal is abnormal or not according to the collected zero sequence voltage signal, and when the zero sequence voltage signal is abnormal, the zero sequence voltage signal is further analyzed and judged to determine a fault branch circuit, so that the working reliability of the power transmission and distribution line is ensured. The invention provides a small current ground fault detection system and method based on zero sequence component analysis, which can judge ground faults in time, determine fault branches and effectively improve the working reliability of a power transmission and distribution line.
Description
Technical Field
the invention belongs to the technical field of power detection, and particularly relates to a small current ground fault detection system and method based on zero sequence component analysis.
background
With the continuous development of science and technology, people use more and more electric energy, and have more and more requirements on electric energy, and the power transmission and distribution line is used as an important carrier of electric energy transmission, and the safe and reliable work of the power transmission and distribution line is an important factor for ensuring the electric energy supply. The ground fault is one of the faults frequently occurring in the power transmission and distribution line, and if the ground fault is not solved in time after the ground fault occurs, serious consequences and even disasters can be caused to the production and life of people. At present, people adopt various detection methods to detect the ground fault, but the detection of the low-current ground fault is difficult. The invention provides a small current ground fault detection system based on zero sequence component analysis, which is used for collecting a zero sequence current signal and a voltage signal of a power transmission line, preliminarily judging whether the power transmission line is abnormal or not according to the collected zero sequence voltage signal, judging the fault condition of the power transmission line by combining the zero sequence current signal when the power transmission line is abnormal, and determining a fault branch, thereby effectively improving the working reliability of the power transmission and distribution line.
Disclosure of Invention
The invention provides a small current ground fault detection system and method based on zero sequence component analysis, which can judge ground faults in time, determine fault branches and effectively improve the working reliability of a power transmission and distribution line.
The invention particularly relates to a low-current ground fault detection system based on zero sequence component analysis, which comprises a current sensor, a voltage sensor, a signal conditioning unit, an A/D conversion unit, a control processing unit, a key input unit, a display unit, a storage unit, an alarm unit and a communication unit, wherein the current sensor and the voltage sensor are respectively connected with the signal conditioning unit; the small current ground fault detection system preliminarily judges whether the zero sequence voltage signal is abnormal or not according to the collected zero sequence voltage signal, and when the zero sequence voltage signal is abnormal, the zero sequence voltage signal is further analyzed and judged to determine a fault branch circuit, so that the working reliability of the power transmission and distribution line is ensured.
the current sensor collects the zero sequence current signal, and the voltage sensor collects the zero sequence voltage signal.
the signal conditioning unit adopts an amplifying circuit to amplify the input signal and outputs a signal meeting the input requirement of the A/D conversion unit.
the key input unit is combined with the storage unit and the display unit to carry out parameter setting and information query on the small current ground fault detection system, and the parameters comprise a sampling frequency, a zero sequence voltage reference value, a lower limit cut-off frequency of the shortest line of the overhead line and a lower limit cut-off frequency of the shortest line of the cable.
And the alarm unit adopts an audible and visual alarm, and timely gives out audible and visual alarm when the low-current ground fault detection system detects a ground fault.
the communication unit uploads the detection information of the low-current ground fault detection system to a monitoring center by adopting a GPRS wireless communication technology, and meanwhile, the communication unit can receive a control instruction of the monitoring center.
The invention also provides a detection method of the small current ground fault detection system based on zero sequence component analysis, which comprises the following steps:
Step (1): acquiring zero-sequence voltage signals and zero-sequence current signals of the power transmission and distribution line;
Step (2): amplifying the signal by the signal conditioning unit;
And (3): performing A/D conversion by the A/D conversion unit;
And (4): judging whether the zero sequence voltage signal is greater than a zero sequence voltage reference value or not, and if so, entering the step (5); if not, returning to the step (1);
And (5): calculating the characteristic frequency band omega > [ min (omega) of the power transmission and distribution line1,ω2),ωc/2]，ω1the lower limit cut-off frequency omega of the shortest line of the overhead line of the power transmission and distribution line2The lower limit cut-off frequency, omega, of the shortest line of the power transmission and distribution line cablecis the sampling frequency;
and (6): extracting zero sequence current signals and zero sequence voltage signals under the characteristic frequency band;
And (7): calculating the integral of the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandI0Is the zero sequence current signal;
And (8): calculating a proportionality coefficient of integrals of the zero sequence voltage signal and the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandU0(n) is a sampling value of the zero sequence voltage signal within the n x Δ T time period within the characteristic frequency band;
And (9): judging whether the proportionality coefficients are all larger than zero, and if so, sending out a transmission line bus fault through the alarm unit and the display unit; if not, entering the step (10);
Step (10): judging whether the proportionality coefficients are all smaller than zero, and if so, displaying that the transmission line has no fault through the display unit; if not, the proportional coefficient is larger than the branch fault corresponding to zero, a ground fault alarm is sent out through the alarm unit and the display unit, and the fault branch is displayed;
Step (11): and uploading the detection information to the monitoring center through the communication unit.
compared with the prior art, the beneficial effects are: the small current ground fault detection system preliminarily judges whether the zero sequence voltage signal is abnormal or not according to the collected zero sequence voltage signal, when the zero sequence voltage signal is abnormal, a proportion coefficient of integral of the zero sequence voltage signal and the zero sequence current signal in the characteristic frequency band within the time period of nxdelta T is calculated by combining the zero sequence current signal, the fault condition of the power transmission line is judged according to the proportion coefficient, and the working reliability of the power transmission and distribution line is ensured.
Drawings
fig. 1 is a schematic structural diagram of a small current ground fault detection system based on zero sequence component analysis according to the present invention.
fig. 2 is a working flow chart of a detection method of a low-current ground fault detection system based on zero sequence component analysis according to the present invention.
Detailed Description
The following describes in detail a specific embodiment of a low-current ground fault detection system based on zero-sequence component analysis according to the present invention with reference to the accompanying drawings.
as shown in fig. 1, the low-current ground fault detection system of the present invention includes a current sensor, a voltage sensor, a signal conditioning unit, an a/D conversion unit, a control processing unit, a key input unit, a display unit, a storage unit, an alarm unit, and a communication unit, where the current sensor and the voltage sensor are respectively connected to the signal conditioning unit, the a/D conversion unit is respectively connected to the signal conditioning unit and the control processing unit, and the control processing unit is also respectively connected to the key input unit, the display unit, the storage unit, the alarm unit, and the communication unit; the small current ground fault detection system preliminarily judges whether the zero sequence voltage signal is abnormal or not according to the collected zero sequence voltage signal, and when the zero sequence voltage signal is abnormal, the zero sequence voltage signal is further analyzed and judged to determine a fault branch circuit, so that the working reliability of the power transmission and distribution line is ensured.
The signal conditioning unit adopts an amplifying circuit to amplify the input signal.
The key input unit is combined with the storage unit and the display unit to carry out parameter setting and information query on the small current ground fault detection system, and the parameters comprise a sampling frequency, a zero sequence voltage reference value, a lower limit cut-off frequency of the shortest line of the overhead line and a lower limit cut-off frequency of the shortest line of the cable.
and the alarm unit adopts an audible and visual alarm, and timely gives out audible and visual alarm when the low-current ground fault detection system detects a ground fault.
The communication unit uploads the detection information of the low-current ground fault detection system to a monitoring center by adopting a GPRS wireless communication technology, and meanwhile, the communication unit can receive a control instruction of the monitoring center.
as shown in fig. 2, the present invention further provides a detection method of a small current ground fault detection system based on zero sequence component analysis, where the detection method includes the following steps:
step (1): acquiring zero-sequence voltage signals and zero-sequence current signals of the power transmission and distribution line;
step (2): amplifying the signal by the signal conditioning unit;
and (3): performing A/D conversion by the A/D conversion unit;
and (4): judging whether the zero sequence voltage signal is greater than a zero sequence voltage reference value or not, and if so, entering the step (5); if not, returning to the step (1);
And (5): calculating the characteristic frequency band omega > [ min (omega) of the power transmission and distribution line1,ω2),ωc/2]，ω1The lower limit cut-off frequency omega of the shortest line of the overhead line of the power transmission and distribution line2The lower limit cut-off frequency, omega, of the shortest line of the power transmission and distribution line cablecIs the sampling frequency;
And (6): extracting zero sequence current signals and zero sequence voltage signals under the characteristic frequency band;
And (7): calculating the integral of the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandI0Is the zero sequence current signal;
And (8): calculating a proportionality coefficient of integrals of the zero sequence voltage signal and the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandU0(n) is a sampling value of the zero sequence voltage signal within the n x Δ T time period within the characteristic frequency band;
and (9): judging whether the proportionality coefficients are all larger than zero, and if so, sending out a transmission line bus fault through the alarm unit and the display unit; if not, entering the step (10);
step (10): judging whether the proportionality coefficients are all smaller than zero, and if so, displaying that the transmission line has no fault through the display unit; if not, the proportional coefficient is larger than the branch fault corresponding to zero, a ground fault alarm is sent out through the alarm unit and the display unit, and the fault branch is displayed;
Step (11): and uploading the detection information to the monitoring center through the communication unit.
The low-current ground fault detection system is suitable for multi-branch power transmission and distribution lines.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (7)
1. A small current ground fault detection system based on zero sequence component analysis is characterized by comprising a current sensor, a voltage sensor, a signal conditioning unit, an A/D conversion unit, a control processing unit, a key input unit, a display unit, a storage unit, an alarm unit and a communication unit, wherein the current sensor and the voltage sensor are respectively connected with the signal conditioning unit; the small current ground fault detection system preliminarily judges whether the zero sequence voltage signal is abnormal or not according to the collected zero sequence voltage signal, and when the zero sequence voltage signal is abnormal, the zero sequence voltage signal is further analyzed and judged to determine a fault branch circuit, so that the working reliability of the power transmission and distribution line is ensured.
2. The system according to claim 1, wherein the current sensor collects the zero sequence current signal, and the voltage sensor collects the zero sequence voltage signal.
3. the system according to claim 2, wherein the signal conditioning unit amplifies the input signal with an amplifying circuit and outputs a signal meeting the input requirement of the a/D conversion unit.
4. The system according to claim 3, wherein the key input unit, in combination with the storage unit and the display unit, performs parameter setting and information query on the system for detecting a low-current ground fault, where the parameters include a sampling frequency, a zero-sequence voltage reference value, a lower cut-off frequency of a shortest line of an overhead line, and a lower cut-off frequency of a shortest line of a cable.
5. The system for detecting the small current ground fault based on the zero sequence component analysis as claimed in claim 4, wherein the alarm unit employs an audible and visual alarm, and the audible and visual alarm is given out when the small current ground fault detection system detects the ground fault.
6. the system according to claim 5, wherein the communication unit uploads the detection information of the low-current ground fault detection system to a monitoring center by using a GPRS wireless communication technology, and can receive a control command from the monitoring center.
7. The detection method of the low-current ground fault detection system based on zero-sequence component analysis according to any one of claims 1-6, characterized in that the detection method comprises the following steps:
step (1): acquiring zero-sequence voltage signals and zero-sequence current signals of the power transmission and distribution line;
Step (2): amplifying the signal by the signal conditioning unit;
And (3): performing A/D conversion by the A/D conversion unit;
And (4): judging whether the zero sequence voltage signal is greater than a zero sequence voltage reference value or not, and if so, entering the step (5); if not, returning to the step (1);
And (5): calculating the characteristic frequency band omega > [ min (omega) of the power transmission and distribution line1,ω2),ωc/2]，ω1the lower limit cut-off frequency omega of the shortest line of the overhead line of the power transmission and distribution line2The lower limit cut-off frequency, omega, of the shortest line of the power transmission and distribution line cablecIs the sampling frequency;
and (6): extracting zero sequence current signals and zero sequence voltage signals under the characteristic frequency band;
And (7): calculating the integral of the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandI0Is the zero sequence current signal;
and (8): calculating a proportionality coefficient of integrals of the zero sequence voltage signal and the zero sequence current signal in the n multiplied by delta T time period in the characteristic frequency bandU0(n) is a sampling value of the zero sequence voltage signal within the n x Δ T time period within the characteristic frequency band;
And (9): judging whether the proportionality coefficients are all larger than zero, and if so, sending out a transmission line bus fault through the alarm unit and the display unit; if not, entering the step (10);
step (10): judging whether the proportionality coefficients are all smaller than zero, and if so, displaying that the transmission line has no fault through the display unit; if not, the proportional coefficient is larger than the branch fault corresponding to zero, a ground fault alarm is sent out through the alarm unit and the display unit, and the fault branch is displayed;
Step (11): and uploading the detection information to the monitoring center through the communication unit.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111220879A (en) * | 2020-01-19 | 2020-06-02 | 重庆大学 | Method for positioning single-phase earth fault section of small current grounding system |
| CN112415259A (en) * | 2020-11-28 | 2021-02-26 | 国网江苏省电力有限公司盐城供电分公司 | Cable overvoltage detection method |
| CN113176521A (en) * | 2021-04-07 | 2021-07-27 | 国网江苏省电力有限公司南通供电分公司 | Single-phase earth fault detection method for power transmission and distribution system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106990324A (en) * | 2017-04-06 | 2017-07-28 | 北京四方继保自动化股份有限公司 | A kind of distribution net work earthing fault detects localization method |
| CN109100613A (en) * | 2018-08-22 | 2018-12-28 | 国网江苏省电力有限公司盐城供电分公司 | It is a kind of based on the distribution network failure on-line checking positioning system measured indirectly |
| CN109521335A (en) * | 2018-11-16 | 2019-03-26 | 国网江苏省电力有限公司盐城供电分公司 | It is a kind of to take the high-voltage cable insulating state on-line detecting system that powered based on self-induction |
-
2019
- 2019-07-11 CN CN201910624127.3A patent/CN110579669A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106990324A (en) * | 2017-04-06 | 2017-07-28 | 北京四方继保自动化股份有限公司 | A kind of distribution net work earthing fault detects localization method |
| CN109100613A (en) * | 2018-08-22 | 2018-12-28 | 国网江苏省电力有限公司盐城供电分公司 | It is a kind of based on the distribution network failure on-line checking positioning system measured indirectly |
| CN109521335A (en) * | 2018-11-16 | 2019-03-26 | 国网江苏省电力有限公司盐城供电分公司 | It is a kind of to take the high-voltage cable insulating state on-line detecting system that powered based on self-induction |
Non-Patent Citations (1)
| Title |
|---|
| 张姝: "配电网弱故障接地保护与定位方法研究", 中国博士学位论文全文数据库 工程科技Ⅱ辑, no. 10, pages 042 - 64 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111220879A (en) * | 2020-01-19 | 2020-06-02 | 重庆大学 | Method for positioning single-phase earth fault section of small current grounding system |
| CN112415259A (en) * | 2020-11-28 | 2021-02-26 | 国网江苏省电力有限公司盐城供电分公司 | Cable overvoltage detection method |
| CN113176521A (en) * | 2021-04-07 | 2021-07-27 | 国网江苏省电力有限公司南通供电分公司 | Single-phase earth fault detection method for power transmission and distribution system |
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