CN113608150A - Single-phase transformer system capable of improving load leakage detection performance and installation method thereof - Google Patents
Single-phase transformer system capable of improving load leakage detection performance and installation method thereof Download PDFInfo
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- CN113608150A CN113608150A CN202110799538.3A CN202110799538A CN113608150A CN 113608150 A CN113608150 A CN 113608150A CN 202110799538 A CN202110799538 A CN 202110799538A CN 113608150 A CN113608150 A CN 113608150A
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- 238000001514 detection method Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000009434 installation Methods 0.000 title abstract description 7
- 238000012544 monitoring process Methods 0.000 claims abstract description 44
- 230000009466 transformation Effects 0.000 claims description 23
- 230000007935 neutral effect Effects 0.000 claims description 11
- 238000012360 testing method Methods 0.000 claims description 8
- 238000012986 modification Methods 0.000 claims description 7
- 230000004048 modification Effects 0.000 claims description 7
- 230000005611 electricity Effects 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 230000005540 biological transmission Effects 0.000 claims description 3
- 238000007689 inspection Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 4
- 230000006378 damage Effects 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 206010014357 Electric shock Diseases 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000016507 interphase Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
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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
- G01R31/62—Testing of transformers
Abstract
The invention relates to a single-phase transformer system capable of improving load leakage detection performance and an installation method thereof, wherein the single-phase transformer system comprises the following steps: the system comprises a single-phase two-wire system transformer, a station grounding grid, a grounding wire and a leakage monitoring CT; one end of the grounding wire is connected with a station grounding grid, and the other end of the grounding wire is connected with one secondary wiring terminal of the single-phase two-wire transformer and used for establishing a leakage current loop and a zero-ground voltage release channel; the leakage monitoring CT is sleeved on two power supply lines on the load side of the single-phase two-wire system transformer and used for detecting leakage current data. The leakage current detection device has a backflow channel, leakage current can be detected by the leakage current detection device and reported to an operator on duty through the monitoring terminal, a basis is provided for follow-up leakage inspection, zero-earth voltage is eliminated, and the phenomenon that electronic equipment such as an RTU (remote terminal unit) is damaged by zero-earth voltage impact is avoided.
Description
Technical Field
The invention belongs to the technical field of power engineering, and relates to a single-phase transformer system and an installation method thereof, in particular to a single-phase transformer system capable of improving load leakage detection performance and an installation method thereof.
Background
The street lamp is a public facility with the largest quantity in a city, the safe operation of the street lamp facility is closely related to the life safety of people, particularly when the flood season comes, the road accumulated water greatly threatens the safe operation of street lamp equipment, when the street lamp pole leaks electricity, if the street lamp pole cannot be timely found and controlled, the potential safety hazard can be greatly generated, the characteristics of large base number and wide distribution of the street lamp pole restrict the manpower investigation efficiency and accuracy, and the addition of the monitoring and alarming function of the remote equipment becomes very important.
However, the current suspension system of the single-phase two-wire transformer has the following problems that the leakage condition cannot be monitored due to the operation mode.
1. The existing street lamp transformer is a single-phase two-wire system transformer, two ends of the low voltage output side of the transformer are both suspended (not grounded), zero ground voltage cannot be released because the transformer is completely isolated from the ground wire, a loop is not formed between the transformer and the ground, and leakage current cannot be detected by a leakage detection device when a lamp post leaks electricity.
2. The normal voltage between the two low-voltage terminals of a single-phase transformer and ground is 0.23kV, but sometimes as high as 1kV or more. If the two ends of the output are respectively a live wire and a zero line, the voltage to ground is regarded as the voltage to zero, when the output generates a higher voltage to zero, the voltage to zero cannot be released because the transformer is completely isolated from the ground, and the voltage to zero in the current power supply state exists certainly.
Upon search, no prior art documents that are the same or similar to the present invention have been found.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a single-phase transformer system capable of improving the load leakage detection performance and an installation method thereof, wherein the single-phase transformer system can enable leakage current to have a backflow channel, and leakage current detection equipment can detect the leakage current.
The invention solves the practical problem by adopting the following technical scheme:
a single-phase transformer system that improves load leakage detection performance, comprising: the system comprises a single-phase two-wire system transformer, a station grounding grid, a grounding wire and a leakage monitoring CT; one end of the grounding wire is connected with a station grounding grid, and the other end of the grounding wire is connected with one secondary wiring terminal of the single-phase two-wire transformer and used for establishing a leakage current loop and a zero-ground voltage release channel; the leakage monitoring CT is sleeved on two power supply lines on the load side of the single-phase two-wire system transformer and used for detecting leakage current data.
And the output end of the electric leakage monitoring CT is also connected with an electric leakage monitoring remote monitoring terminal, and the electric leakage monitoring remote monitoring terminal is used for outputting the collected electric leakage current data to a monitoring platform.
And the leakage monitoring CT selects a high-precision current transformer at milliampere level.
And the neutral line is selected from a copper bar or a cable at the output end.
A method for installing a single-phase transformer system capable of improving load leakage detection performance comprises the following steps:
step 1, selecting a low-voltage side transformation phase of a single-phase transformer, respectively testing two-phase ground voltages of the transformer by using a universal meter before transformation, and selecting one phase as the transformation phase if the two-phase ground voltages are about 110 v; if the voltage of one phase is 0V, carrying out grounding transformation on the phase;
step 3, selecting a grounding wire or a grounding bar with sufficient current-carrying capacity according to the actual situation of the station to be reconstructed;
step 5, setting one of two output ends of the single-phase transformer as a phase line and one as a neutral line, and grounding the neutral line by connecting two ends of a grounding wire with an in-station earth electrode firstly and then connecting a terminal of the transformer;
step 6, installing a street lamp intelligent control terminal, and sleeving a leakage transformer in a power supply loop;
and 7, removing the ground wire, recovering power transmission and debugging the four-remote function of the monitoring terminal.
The invention has the advantages and beneficial effects that:
1. the invention provides a single-phase transformer system capable of improving load leakage detection performance and an installation method thereof.A grounding wire is additionally arranged on a secondary terminal of the single-phase transformer, two power supply wires on a load side are sleeved in the same high-precision CT, meanwhile, the grounding reliability of each base lamp pole is ensured, the leakage current is provided with a backflow channel after the single-phase transformer system is transformed, leakage current detection equipment can detect the leakage current, the leakage current is reported to an operator on duty through a monitoring terminal, a basis is provided for follow-up leakage inspection, the zero ground voltage is eliminated, and the occurrence of the event that the zero ground voltage impacts and damages electronic equipment such as an RTU (remote terminal unit) is avoided.
2. After the transformation, the zero-earth voltage of the original system cannot deviate, the problem that the zero-sequence voltage impacts electronic equipment due to overhigh zero-earth voltage is avoided, the safe and stable operation of automatic electronic equipment in a street lamp system is further ensured, the street lamp equipment is ensured to realize the functions of remote measurement, remote signaling, remote regulation and remote control, the opening and closing control flexibility of the street lamp is enhanced, the real-time performance of state monitoring, the reliability of remote emergency opening and closing and the like, the operation efficiency is greatly improved, and the urban development is assisted.
3. The invention builds the leakage current loop and the zero earth voltage release channel by transforming the single-phase two-wire transformer, and is matched with the leakage remote monitoring equipment and system, so that the original system can be added with the leakage monitoring function, and when the leakage current occurs, the leakage current can be found at the first time and can be timely treated, thereby avoiding the occurrence of the leakage hurting event.
Drawings
FIG. 1 is a schematic diagram of a single-phase transformer power supply system of the present invention;
FIG. 2 is a schematic diagram of the present invention of a single-phase transformer;
FIG. 3 is a schematic diagram of the operation of the single-phase transformer of the present invention after modification;
FIG. 4 is a schematic diagram of an experimental wiring mode before the transformation of the single-phase transformer of the invention;
fig. 5 is a schematic diagram of an experimental wiring mode of the single-phase transformer after modification.
Detailed Description
The embodiments of the invention will be described in further detail below with reference to the accompanying drawings:
a single-phase transformer system capable of improving load leakage detection performance, as shown in fig. 1 to 3, comprising: a single-phase two-wire transformer, a station grounding grid, a grounding wire and a leakage monitoring CT (i.e., a leakage transformer in fig. 2 and 3); one end of the grounding wire is connected with a station grounding grid, and the other end of the grounding wire is connected with one secondary wiring terminal of the single-phase two-wire transformer and used for establishing a leakage current loop and a zero-ground voltage release channel; the leakage monitoring CT is sleeved on two power supply lines on the load side of the single-phase two-wire system transformer and used for detecting leakage current data.
The output end of the electric leakage monitoring CT is also connected with an electric leakage monitoring remote monitoring terminal, and the electric leakage monitoring remote monitoring terminal is used for outputting the collected electric leakage current data to a monitoring platform.
And the leakage monitoring CT selects a high-precision current transformer at the milliampere level.
The neutral line is made of copper bars or cables at the output end.
In this embodiment, the present invention will be further explained with reference to the accompanying drawings:
FIG. 1 is a diagram of a power supply system for a single-phase transformer according to the present invention, which includes an existing single-phase two-wire transformer, an in-station reliable grounding grid, and a newly added reliable grounding wire, wherein one end of the reliable grounding wire is connected to one of the secondary connecting terminals of the transformer, and the other end of the reliable grounding wire is reliably connected to the station grounding grid; the high-precision CT is increased newly, two power supply lines on the load side are sleeved in the same high-precision CT, the high-precision CT is matched with an existing pole-by-pole grounding mode of a street lamp pole, a leakage current loop and a zero ground voltage release channel are established, a leakage monitoring remote monitoring terminal is synchronously matched, found problems can be returned at the first time, and an operator on duty is guided to take measures.
The grounding resistance in the station is not more than 10 ohms, the grounding resistance of the lamp pole side protection is not more than 4 ohms, and a high-precision product is selected for the leakage monitoring CT.
As shown in fig. 2 and 3, the existing operation mode and the operation mode after transformation are respectively, through various tests on the transformer for the first time and the second time, the detection voltage and current data show that the operation of the system cannot be influenced after transformation, the leakage current transformer does not detect the data before transformation, and the leakage current value can be detected after transformation. The results demonstrate that the retrofit protocol is feasible.
In order to ensure the feasibility of the scheme in the implementation process, the isolation transformer with the same principle is selected for laboratory test, and the experimental wiring is shown as fig. 4 and 5.
In this embodiment, a resistor with a resistance value in the range of 1000 Ω -1500 Ω is selected for human body resistance in daily environment to simulate the situation of human body electric shock injury.
Through various tests on the transformer for one time and two times, the detection voltage and current data do not influence the operation of the system after being represented and modified.
Before transformation, the leakage current transformer in the figure 4 does not detect data, and after transformation, the leakage current value can be detected in the figure 5. The results demonstrate that the retrofit protocol is feasible.
A method for installing a single-phase transformer system capable of improving load leakage detection performance comprises the following steps:
step 1, selecting a low-voltage side transformation phase of a single-phase transformer, respectively testing two-phase ground voltages of the transformer by using a universal meter before transformation, and selecting one phase as the transformation phase if the two-phase ground voltages are about 110 v; if the voltage of one phase is 0V, the situation shows that serious grounding exists in the load circuit of the 0V voltage of the station, and the phase is subjected to grounding transformation.
And 2, determining that grounding is reliable, determining that the grounding resistance in the station is not more than 10 ohms and the grounding resistance of load equipment on a lamp post of the station is not more than 4 ohms before modification and implementation, and if the grounding resistance is lower than the standard, continuously reducing the grounding resistance.
And 3, selecting a grounding wire or a grounding bar with sufficient current-carrying capacity according to the actual situation of the station to be reconstructed.
And 4, making field safety measures, and performing power failure electricity testing and grounding on the modified station.
And 5, setting one of two output ends of the single-phase transformer as a phase line and one as a neutral line, and grounding the neutral line by connecting two ends of the grounding wire with the earth pole in the station firstly and then connecting the terminals of the transformer.
And 6, installing an intelligent control terminal of the street lamp, and sleeving a leakage transformer in a power supply loop.
And 7, removing the ground wire, recovering power transmission and debugging the four-remote function of the monitoring terminal.
The invention simultaneously analyzes the risk points existing in the modification process, prevents the risks in advance in the modification implementation process, and analyzes the following steps:
the transformation scheme changes the original isolation operation characteristics. The zero ground voltage problem is solved, and zero ground short circuit must be carried out at the output end of the single-phase transformer. But the complete isolation to the ground is lost due to the zero-ground short circuit of the output end of the single-phase transformer. People can get an electric shock when standing on the ground and touching the live wire at the output end of the transformer. Therefore, the good insulation of the modified line must be ensured before the experiment, and the grounding of the lamp post is reliable. And adjusting the corresponding protection equipment specification fixed value according to the line load condition.
Setting one of two output ends of the original single-phase transformer as a phase line and one as a neutral line; the output end of the neutral wire of the original single-phase transformer can be directly grounded by a copper bar or a cable, and the grounding wire must be reliably connected.
After the grounding wire is installed, when the transformer runs, the grounding wire is strictly forbidden to be manually removed, otherwise, personal safety accidents or damage to electric equipment can be caused in the removing process.
And (4) detecting the grounding resistance according to the standard requirement, if the resistance value does not meet the requirement, adopting a measure of reducing the grounding resistance, and then detecting until the resistance value is qualified.
Before transformation, the phase ground voltage of the transformer is determined, the two-phase ground voltage of the transformer is respectively tested by using a universal meter (normally, the voltage of the two phases of the transformer is about 110V), if one phase is 0, the 0V voltage of the station is seriously grounded, the phase is subjected to ground transformation, the other phase cannot be transformed, and otherwise, an inter-phase short circuit fault is caused.
The working principle of the invention is as follows:
during the use, the electric leakage condition that electric leakage monitoring CT can take place in the circuit in time monitors, and good lamp pole ground connection can be guaranteed the problem very first time and be kept apart with protection definite value setting in the station, avoids taking place to electrocute the incident. Meanwhile, the electric leakage remote monitoring equipment transmits the acquired data to the person on duty, and the monitoring person on duty takes measures in time after knowing the electric leakage problem, so that the defect elimination efficiency is improved.
It should be emphasized that the examples described herein are illustrative and not restrictive, and thus the present invention includes, but is not limited to, those examples described in this detailed description, as well as other embodiments that can be derived from the teachings of the present invention by those skilled in the art and that are within the scope of the present invention.
Claims (5)
1. A single-phase transformer system capable of improving load leakage detection performance is characterized in that: the method comprises the following steps: the system comprises a single-phase two-wire system transformer, a station grounding grid, a grounding wire and a leakage monitoring CT; one end of the grounding wire is connected with a station grounding grid, and the other end of the grounding wire is connected with one secondary wiring terminal of the single-phase two-wire transformer and used for establishing a leakage current loop and a zero-ground voltage release channel; the leakage monitoring CT is sleeved on two power supply lines on the load side of the single-phase two-wire system transformer and used for detecting leakage current data.
2. The single-phase transformer system capable of improving the load leakage detection performance according to claim 1, wherein: the output end of the electric leakage monitoring CT is also connected with an electric leakage monitoring remote monitoring terminal, and the electric leakage monitoring remote monitoring terminal is used for outputting the collected electric leakage current data to a monitoring platform.
3. The single-phase transformer system capable of improving the load leakage detection performance according to claim 1, wherein: and the leakage monitoring CT selects a high-precision current transformer at the milliampere level.
4. The single-phase transformer system capable of improving the load leakage detection performance according to claim 1, wherein: the neutral line is made of copper bars or cables at the output end.
5. A method for installing a single-phase transformer system capable of improving load leakage detection performance is characterized in that: the method comprises the following steps:
step 1, selecting a low-voltage side transformation phase of a single-phase transformer, respectively testing two-phase ground voltages of the transformer by using a universal meter before transformation, and selecting one phase as the transformation phase if the two-phase ground voltages are about 110 v; if the voltage of one phase is 0V, carrying out grounding transformation on the phase;
step 2, determining that grounding is reliable, determining that grounding resistance in the station is not more than 10 ohms and grounding resistance of load equipment of a lamp post of the station is not more than 4 ohms before modification and implementation, and if the grounding resistance is lower than the standard, continuously reducing the grounding resistance;
step 3, selecting a grounding wire or a grounding bar with sufficient current-carrying capacity according to the actual situation of the station to be reconstructed;
step 4, making field safety measures, and grounding the modified station after power failure and electricity testing;
step 5, setting one of two output ends of the single-phase transformer as a phase line and one as a neutral line, and grounding the neutral line by connecting two ends of a grounding wire with an in-station earth electrode firstly and then connecting a terminal of the transformer;
step 6, installing a street lamp intelligent control terminal, and sleeving a leakage transformer in a power supply loop;
and 7, removing the ground wire, recovering power transmission and debugging the four-remote function of the monitoring terminal.
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| CN202110799538.3A CN113608150A (en) | 2021-07-15 | 2021-07-15 | Single-phase transformer system capable of improving load leakage detection performance and installation method thereof |
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Citations (7)
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|---|---|---|---|---|
| KR20080015650A (en) * | 2006-08-16 | 2008-02-20 | 김보경 | Electric leakage detecting system |
| CN101138139A (en) * | 2005-01-04 | 2008-03-05 | 科技研究公司 | Leakage current detection and interruption circuit |
| JP2009245791A (en) * | 2008-03-31 | 2009-10-22 | Panasonic Electric Works Co Ltd | Wiring instrument |
| JP2011153910A (en) * | 2010-01-27 | 2011-08-11 | Patokkusu Japan Kk | Leak current measuring device and measurement method in electric apparatus |
| KR20110112966A (en) * | 2010-04-08 | 2011-10-14 | 강동철 | Electronic circuit and signal processing method of auto reset earth leakage breaker |
| KR20170007686A (en) * | 2015-07-11 | 2017-01-19 | 이현창 | The apparatus and method to locate the leaking point efficiently under TN-C environment |
| CN112285617A (en) * | 2020-10-23 | 2021-01-29 | 南京谷贝电气科技有限公司 | Transformer electrical fault early warning system and device |
-
2021
- 2021-07-15 CN CN202110799538.3A patent/CN113608150A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101138139A (en) * | 2005-01-04 | 2008-03-05 | 科技研究公司 | Leakage current detection and interruption circuit |
| KR20080015650A (en) * | 2006-08-16 | 2008-02-20 | 김보경 | Electric leakage detecting system |
| JP2009245791A (en) * | 2008-03-31 | 2009-10-22 | Panasonic Electric Works Co Ltd | Wiring instrument |
| JP2011153910A (en) * | 2010-01-27 | 2011-08-11 | Patokkusu Japan Kk | Leak current measuring device and measurement method in electric apparatus |
| KR20110112966A (en) * | 2010-04-08 | 2011-10-14 | 강동철 | Electronic circuit and signal processing method of auto reset earth leakage breaker |
| KR20170007686A (en) * | 2015-07-11 | 2017-01-19 | 이현창 | The apparatus and method to locate the leaking point efficiently under TN-C environment |
| CN112285617A (en) * | 2020-10-23 | 2021-01-29 | 南京谷贝电气科技有限公司 | Transformer electrical fault early warning system and device |
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Effective date of registration: 20220617 Address after: 300010 Tianjin city Hebei District Wujing Road No. 39 Applicant after: STATE GRID TIANJIN ELECTRIC POWER Co. Applicant after: STATE GRID CORPORATION OF CHINA Applicant after: TIANJIN STREET LAMP MANAGEMENT OFFICE Address before: 300010 Tianjin city Hebei District Wujing Road No. 39 Applicant before: STATE GRID TIANJIN ELECTRIC POWER Co. Applicant before: STATE GRID CORPORATION OF CHINA Applicant before: TIANJIN STREET LAMP MANAGEMENT OFFICE Applicant before: TIANJIN ELECTRIC POWER INDUSTRIAL BUREAU STREET LAMP DIVISION MATERIAL CO. Applicant before: TIANJIN LUMING ELECTRIC POWER EQUIPMENT SALES CO.,LTD. |