CN110794335A - Single-phase grounding detection system based on waveform difference and detection method thereof - Google Patents
Single-phase grounding detection system based on waveform difference and detection method thereof Download PDFInfo
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- CN110794335A CN110794335A CN201911236094.1A CN201911236094A CN110794335A CN 110794335 A CN110794335 A CN 110794335A CN 201911236094 A CN201911236094 A CN 201911236094A CN 110794335 A CN110794335 A CN 110794335A
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- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
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Abstract
The invention provides a single-phase grounding detection system based on waveform difference, which comprises a zero-sequence current acquisition unit, a voltage acquisition unit, a control processing unit, a key input unit, a storage unit, a display unit, an alarm unit and a communication unit, wherein the zero-sequence current acquisition unit is used for acquiring a current; the detection system judges the earth fault phase according to the acquired signals, and then judges the earth fault line according to the difference of zero sequence current in the earth fault. The invention provides a single-phase grounding detection system and method based on waveform difference, which can accurately and quickly judge a fault phase and a specific fault line when a grounding fault occurs, and ensure the working reliability of a distribution line.
Description
Technical Field
The invention belongs to the technical field of power detection, and particularly relates to a single-phase grounding detection system based on waveform difference and a detection method thereof.
Background
When a single-phase earth fault occurs in the system, a small zero-sequence current is generated, the line voltages of the zero-sequence current are almost consistent, and the zero-sequence current does not have great influence on the load power supply, so that the zero-sequence current can be immediately tripped. Most of the power systems used in China can still normally operate for 1-2 hours after single-phase earth faults occur, so that negative effects brought to users by sudden power supply interruption are prevented, and with wide application of a resonant grounding mode and gradual rise of power supply quality safety requirements of users. Although the system can normally operate after the ground fault occurs, the voltage to earth of a non-fault phase rises, the insulation at the weak link of the system is easily damaged by long-time work with the fault, and further two-phase short circuit and even three-phase short circuit are caused, if the arc grounding occurs, the overvoltage of the whole system can be caused, and great threat is brought to the stable operation of the whole power grid. Therefore, an accurate determination of the failure point is required.
The invention provides a single-phase grounding detection system based on waveform difference and a detection method thereof.
Disclosure of Invention
The invention provides a single-phase grounding detection system and method based on waveform difference, which can accurately and quickly judge a fault phase and a specific fault line when a grounding fault occurs, and ensure the working reliability of a distribution line.
The invention particularly relates to a single-phase grounding detection system based on waveform difference, which comprises a zero-sequence current acquisition unit, a voltage acquisition unit, a control processing unit, a key input unit, a storage unit, a display unit, an alarm unit and a communication unit, wherein the control processing unit is respectively connected with the zero-sequence current acquisition unit, the voltage acquisition unit, the key input unit, the storage unit, the display unit, the alarm unit and the communication unit; the detection system judges the earth fault phase according to the acquired signals, and then judges the earth fault line according to the difference of zero sequence current in the earth fault.
The zero-sequence current acquisition unit acquires zero-sequence current signals of all lines by adopting a zero-sequence current sensor; the voltage acquisition unit adopts a voltage sensor to acquire voltage signals of each phase.
The display unit adopts an LCD display screen, and is matched with the key input unit and the storage unit to set parameters of the detection system.
The alarm unit adopts an audible and visual alarm, and can send out alarm signals in time when a ground fault occurs.
The communication unit uploads the information of the detection system to a monitoring center by adopting a wireless communication technology and comprises an RF905 wireless receiving module and a wireless sending module, wherein the wireless receiving module can receive a control instruction of the monitoring center and set parameters, and the wireless sending module uploads the information of the detection system to the monitoring center.
The invention also provides a detection method of the single-phase grounding detection system based on the waveform difference, which comprises the following steps:
step (1): the voltage acquisition unit acquires voltage signals of each phase;
step (2): the control processing unit judges whether one phase of the phase voltage signals is reduced to zero, the other two phases of the phase voltage signals are increased to the value of line voltage, if yes, the step (3) is carried out; if not, returning to the step (1);
and (3): controlling the alarm unit to give an alarm, and displaying a fault on the display screen: a phase corresponding to zero phase voltage drop has a ground fault;
and (4): controlling the communication unit to upload alarm information to the monitoring center;
and (5): acquiring zero-sequence current signals of all lines of a fault phase, and recording zero-sequence current signal data of each period before and after the fault;
and (6): and carrying out pairwise correlation analysis on the zero sequence current signals extracted by each line, and solving pairwise correlation coefficients between the lines:
ix(n) is zero sequence current signal of x line, iy(N) is a zero sequence current signal of the y line, and N is the sampling number in one signal period;
and (7): calculating the comprehensive correlation coefficient of each line:
m is the total number of lines;
and (8): comparing the numerical values of the comprehensive correlation coefficients of all lines to obtain the maximum value of the comprehensive correlation coefficients;
and (9): comparing the numerical values of the comprehensive correlation coefficients of all lines to obtain the minimum value of the comprehensive correlation coefficients;
step (10): calculating the difference value between the maximum value of the comprehensive correlation coefficient and the minimum value of the comprehensive correlation coefficient;
step (11): judging whether the difference value is larger than a difference value reference value or not, if so, entering a step (8); if not, entering the step (9);
step (12): judging that the bus is in fault, and entering the step (14);
step (13): and (5) judging that the line fault is the line fault where the minimum value difference value of the comprehensive correlation coefficient is positioned, and entering the step (15).
Step (14): controlling the display screen to display bus faults and controlling the communication unit to upload bus fault information to the monitoring center;
step (15): and controlling the display screen to display the line fault where the minimum difference value is located, and controlling the communication unit to upload fault information to the monitoring center.
Compared with the prior art, the detection system firstly determines whether the ground fault and the fault phase occur according to the phase voltage signal, then calculates the difference of the faulted line and the faultless line in signal waveform according to the consistency principle of zero sequence current, and accurately judges to obtain the fault line.
Drawings
Fig. 1 is a structural diagram of a single-phase grounding detection system based on waveform differences according to the present invention.
FIG. 2 is a flowchart of the operation of the single-phase grounding detection system detection method based on waveform difference according to the present invention
Detailed Description
The following describes in detail a specific embodiment of a single-phase ground detection system based on waveform differences according to the present invention with reference to the accompanying drawings.
As shown in fig. 1, the detection system of the present invention includes a zero-sequence current collection unit, a voltage collection unit, a control processing unit, a key input unit, a storage unit, a display unit, an alarm unit, and a communication unit, wherein the control processing unit is respectively connected to the zero-sequence current collection unit, the voltage collection unit, the key input unit, the storage unit, the display unit, the alarm unit, and the communication unit.
The zero-sequence current acquisition unit acquires zero-sequence current signals of all lines by adopting a zero-sequence current sensor; the voltage acquisition unit adopts a voltage sensor to acquire voltage signals of each phase.
The display unit adopts an LCD display screen and is matched with the key input unit and the storage unit to set parameters of the detection system.
The alarm unit adopts an audible and visual alarm, and can send out alarm signals in time when a ground fault occurs.
The communication unit uploads the information of the detection system to the monitoring center by adopting a wireless communication technology, and comprises an RF905 wireless receiving module and a wireless sending module, wherein the wireless receiving module can receive a control instruction of the monitoring center and set parameters, and the wireless sending module uploads the information of the detection system to the monitoring center.
As shown in fig. 2, the detection method of the single-phase grounding detection system based on waveform difference of the present invention includes the following steps:
step (1): the voltage acquisition unit acquires voltage signals of each phase;
step (2): the control processing unit judges whether one phase of the phase voltage signals is reduced to zero, the other two phases are increased to the value of the line voltage, if yes, the step (3) is carried out; if not, returning to the step (1);
and (3): the control alarm unit sends out the warning to carry out fault display on the display screen: a phase corresponding to zero phase voltage drop has a ground fault;
and (4): the control communication unit uploads the alarm information to a monitoring center;
and (5): acquiring zero-sequence current signals of all lines of a fault phase, and recording zero-sequence current signal data of each period before and after the fault;
and (6): and performing pairwise correlation analysis on the zero sequence current signals extracted by each line, and solving pairwise correlation coefficients between the lines:
ix(n) is zero sequence current signal of x line, iy(N) is a zero sequence current signal of the y line, and N is the sampling number in one signal period;
and (7): calculating the comprehensive correlation coefficient of each line:
m is the total number of lines;
and (8): comparing the magnitude of the comprehensive correlation coefficient of each line to obtain the maximum value of the comprehensive correlation coefficient;
and (9): comparing the magnitude of the comprehensive correlation coefficient of each line to obtain the minimum value of the comprehensive correlation coefficient;
step (10): calculating the difference value between the maximum value of the comprehensive correlation coefficient and the minimum value of the comprehensive correlation coefficient;
step (11): judging whether the difference value is larger than the difference value reference value, if so, entering the step (8); if not, entering the step (9);
step (12): judging that the bus is in fault, and entering the step (14);
step (13): and (5) judging that the line fault is located by the minimum value difference value of the comprehensive correlation coefficient, and entering the step (15).
Step (14): the control display screen displays the bus fault, and the control communication unit uploads the bus fault information to the monitoring center;
step (15): and controlling the display screen to display the line fault where the minimum difference value is located, and controlling the communication unit to upload the fault information to the monitoring center.
The difference reference value is determined according to the total number of the system lines and is generally taken as a value
When a single-phase earth fault occurs, on one hand, a worker needs to manually select a line, and performs power failure on a distribution line without the single-phase earth fault, so that normal power supply is interrupted, and the reliability of power supply is influenced.
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 (6)
1. The single-phase grounding detection system based on waveform difference is characterized by comprising a zero-sequence current acquisition unit, a voltage acquisition unit, a control processing unit, a key input unit, a storage unit, a display unit, an alarm unit and a communication unit, wherein the control processing unit is respectively connected with the zero-sequence current acquisition unit, the voltage acquisition unit, the key input unit, the storage unit, the display unit, the alarm unit and the communication unit; the detection system judges the earth fault phase according to the acquired signals, and then judges the earth fault line according to the difference of zero sequence current in the earth fault.
2. The system according to claim 1, wherein the zero-sequence current acquisition unit acquires zero-sequence current signals of all lines by using a zero-sequence current sensor; the voltage acquisition unit adopts a voltage sensor to acquire voltage signals of each phase.
3. The system according to claim 1, wherein the display unit is an LCD display screen, and the key input unit and the storage unit are used to set parameters of the detection system.
4. The system for detecting the single-phase grounding based on the waveform difference as claimed in claim 1, wherein the alarm unit employs an audible and visual alarm, and can send out an alarm signal in time when a grounding fault occurs.
5. The system according to claim 1, wherein the communication unit uploads the information of the detection system to a monitoring center by using a wireless communication technology, and the system comprises an RF905 wireless receiving module and a wireless transmitting module, the wireless receiving module can receive the control command of the monitoring center and perform the parameter setting, and the wireless transmitting module uploads the information of the detection system to the monitoring center.
6. The detection method of the single-phase grounding detection system based on the waveform difference as claimed in any one of claims 1 to 5, wherein the detection method comprises the following steps:
step (1): the voltage acquisition unit acquires voltage signals of each phase;
step (2): the control processing unit judges whether one phase of the phase voltage signals is reduced to zero, the other two phases of the phase voltage signals are increased to the value of line voltage, if yes, the step (3) is carried out; if not, returning to the step (1);
and (3): controlling the alarm unit to give an alarm, and displaying a fault on the display screen: a phase corresponding to zero phase voltage drop has a ground fault;
and (4): controlling the communication unit to upload alarm information to the monitoring center;
and (5): acquiring zero-sequence current signals of all lines of a fault phase, and recording zero-sequence current signal data of each period before and after the fault;
and (6): and carrying out pairwise correlation analysis on the zero sequence current signals extracted by each line, and solving pairwise correlation coefficients between the lines:ix(n) is zero sequence current signal of x line, iy(N) is a zero sequence current signal of the y line, and N is the sampling number in one signal period;
and (7): calculating the comprehensive correlation coefficient of each line:
m is the total number of lines;
and (8): comparing the numerical values of the comprehensive correlation coefficients of all lines to obtain the maximum value of the comprehensive correlation coefficients;
and (9): comparing the numerical values of the comprehensive correlation coefficients of all lines to obtain the minimum value of the comprehensive correlation coefficients;
step (10): calculating the difference value between the maximum value of the comprehensive correlation coefficient and the minimum value of the comprehensive correlation coefficient;
step (11): judging whether the difference value is larger than a difference value reference value or not, if so, entering a step (8); if not, entering the step (9);
step (12): judging that the bus is in fault, and entering the step (14);
step (13): and (5) judging that the line fault is the line fault where the minimum value difference value of the comprehensive correlation coefficient is positioned, and entering the step (15).
Step (14): controlling the display screen to display bus faults and controlling the communication unit to upload bus fault information to the monitoring center;
step (15): and controlling the display screen to display the line fault where the minimum difference value is located, and controlling the communication unit to upload fault information to the monitoring center.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113702893A (en) * | 2021-09-23 | 2021-11-26 | 云南电网有限责任公司电力科学研究院 | Method and device for evaluating transient waveform transmission consistency of direct current transformer |
| CN114660398A (en) * | 2022-01-29 | 2022-06-24 | 北京合信锐风新能源发展有限公司 | Wind power plant fault detection method and device |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101022216A (en) * | 2007-02-07 | 2007-08-22 | 燕山大学 | Small earthing current electric network single phase fault wire selecting method and apparatus |
| CN101452038A (en) * | 2007-11-29 | 2009-06-10 | 上海蓝瑞软件技术有限公司 | Low current neutral grounding electric network single-phase earth fault diagnostic method |
| CN102937687A (en) * | 2012-10-26 | 2013-02-20 | 杨万钟 | Method for distinguishing disconnection fault and grounding fault during grounding of neutral point through small resistor |
| CN103675605A (en) * | 2013-12-11 | 2014-03-26 | 湖南大学 | Small-current earth fault line selection method based on fault signal transient state correlation analysis |
| CN107561414A (en) * | 2017-10-31 | 2018-01-09 | 国家电网公司 | Rapidly find out the selection method and wire selection system in single-phase grounded malfunction in grounded system of low current loop |
| CN108508320A (en) * | 2018-03-28 | 2018-09-07 | 山东大学 | Arc grounding fault identification method based on harmonic energy and wave distortion feature |
| CN110275086A (en) * | 2019-07-25 | 2019-09-24 | 国网江苏省电力有限公司淮安供电分公司 | The single-phase grounding selecting method and device of more entry conditions |
-
2019
- 2019-12-05 CN CN201911236094.1A patent/CN110794335A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101022216A (en) * | 2007-02-07 | 2007-08-22 | 燕山大学 | Small earthing current electric network single phase fault wire selecting method and apparatus |
| CN101452038A (en) * | 2007-11-29 | 2009-06-10 | 上海蓝瑞软件技术有限公司 | Low current neutral grounding electric network single-phase earth fault diagnostic method |
| CN102937687A (en) * | 2012-10-26 | 2013-02-20 | 杨万钟 | Method for distinguishing disconnection fault and grounding fault during grounding of neutral point through small resistor |
| CN103675605A (en) * | 2013-12-11 | 2014-03-26 | 湖南大学 | Small-current earth fault line selection method based on fault signal transient state correlation analysis |
| CN103675605B (en) * | 2013-12-11 | 2016-03-09 | 湖南大学 | A kind of power distribution network earth fault line selection method based on the correlation analysis of fault-signal transient state |
| CN107561414A (en) * | 2017-10-31 | 2018-01-09 | 国家电网公司 | Rapidly find out the selection method and wire selection system in single-phase grounded malfunction in grounded system of low current loop |
| CN108508320A (en) * | 2018-03-28 | 2018-09-07 | 山东大学 | Arc grounding fault identification method based on harmonic energy and wave distortion feature |
| CN110275086A (en) * | 2019-07-25 | 2019-09-24 | 国网江苏省电力有限公司淮安供电分公司 | The single-phase grounding selecting method and device of more entry conditions |
Non-Patent Citations (2)
| Title |
|---|
| 束洪春等: "谐振接地电网故障选线相关分析法", 《电力自动化设备》 * |
| 陈博博等: "小电流接地系统单相接地综合电弧模型与选线方法的研究", 《电力系统保护与控制》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113702893A (en) * | 2021-09-23 | 2021-11-26 | 云南电网有限责任公司电力科学研究院 | Method and device for evaluating transient waveform transmission consistency of direct current transformer |
| CN113702893B (en) * | 2021-09-23 | 2023-11-21 | 云南电网有限责任公司电力科学研究院 | Transient waveform transmission consistency evaluation method and device for direct current transformer |
| CN114660398A (en) * | 2022-01-29 | 2022-06-24 | 北京合信锐风新能源发展有限公司 | Wind power plant fault detection method and device |
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Application publication date: 20200214 |