CN103837775A - Grounding grid corrosion diagnostic method and device - Google Patents
Grounding grid corrosion diagnostic method and device Download PDFInfo
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- CN103837775A CN103837775A CN201410098954.0A CN201410098954A CN103837775A CN 103837775 A CN103837775 A CN 103837775A CN 201410098954 A CN201410098954 A CN 201410098954A CN 103837775 A CN103837775 A CN 103837775A
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- grounding grid
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Abstract
The invention discloses a grounding grid corrosion diagnostic method and device. The method comprises the steps of injecting sinusoidal alternating currents the frequency of which is not 50 Hz into a grounding grid, measuring the potential rise and reference supply bus voltage of an observation point, calculating the percentage of the reference supply bus voltage of the observation point, simulating an intact grounding grid with simulation software and calculating the percentage of the reference supply bus voltage of the observation point, obtaining the difference value between the percentage of the reference supply bus voltage of the actual observation point and the percentage of the reference supply bus voltage calculated by the simulation software, and judging whether the percentage difference value of the reference supply bus voltage of the observation point meets a preset condition. According to the grounding grid corrosion diagnostic method and device, large-area excavation of the grounding grid is not needed, huge waste of labor, material resources and financial resources is avoided, limitation of operating conditions on site is eliminated, normal operation of an electric system is guaranteed, the application prospect is wide, and market value is high.
Description
Technical field
The present invention relates to electrical network field, be specifically related to a kind of method and device of corrosion diagnosis of grounding grid.
Background technology
Substation grounding device is the important component part of safe operation of power system.It not only provides a public potential reference ground for various electrical equipments in transformer station, and in the time that system breaks down, can also drain rapidly fault current and reduce the earth potential liter of transformer station.The quality of Grounding performance is directly connected to staff's personal safety and the safety of various electrical equipments and normally operation in transformer station.China's grounded screen generally adopts the steel material such as band steel, round steel.In the place of south and the rainy weather of East Coastal, along with the increase of the time limit, the generation corrosion of ground connection Netease is even ruptured and has been brought serious harm to the normal operation of electric system.
In Practical Project, more original for the measurement means of grounded screen fault point, often according to regional soil corrosion rate, empirically estimate grounded screen conductor extent of corrosion, then sampling excavates inspection.This method with blindness, workload is large, speed is slow, and is subject to the restriction of on-the-spot service condition, can not judge exactly extent of corrosion and breakpoint.Meanwhile, transformer station is bearing the important task of national product and people's lives, and each interruption maintenance all inevitably brings many economic losses, brings difficulty to practical operation.Electric system in the urgent need to find a kind of easy, not limited by on-the-spot service condition, realize in the situation that not having a power failure and not excavating the method that grounded screen is diagnosed.
Summary of the invention
For solving the deficiency of prior art existence, the invention discloses a kind of method and device of corrosion diagnosis of grounding grid, avoid a large amount of human and material resources, the waste of financial resources, be not also subject to the restriction of on-the-spot service condition simultaneously.
For achieving the above object, concrete scheme of the present invention is as follows:
A method for corrosion diagnosis of grounding grid, comprises the following steps:
Step 1: to grounded screen injected frequency and the big or small simple sinusoidal alternating current that differs from the optional frequency of 50Hz;
Step 2: utilize measurement mechanism measure observation station potential rise and with reference to bus supply voltage;
Step 3: the reference power source busbar voltage number percent that calculates actual observation point;
Step 4: utilize simulation software to carry out emulation to intact grounded screen, utilize simulation software calculating observation point reference power source busbar voltage number percent;
Step 5: the reference voltage percentage of actual observation being put to reference voltage number percent and simulation software calculating likens difference to;
Step 6: whether the reference power source busbar voltage percentage difference that judges observation point meets pre-conditioned.
In described step 2, described measurement mechanism is current potential control pin.
In described step 2, described observation station spreads all over whole grounded screen.
In described step 3, the potential rise that reference power source busbar voltage number percent is observation station is multiplied by 100% divided by the potential rise of electric current decanting point.
When measuring, described observation station selects potential rise point-blank and with reference to bus supply voltage.
In described step 6, when judgement: in the time of reference voltage percentage difference≤1, do not corrode, in the time of reference voltage percentage difference≤5, slightly corrosion, in the time of reference voltage percentage difference ﹥ 5, heavy corrosion.
Described simulation software is CDEGS simulation calculation software.
A kind of corrosion diagnosis of grounding grid device, comprise the potential pole, the backflow utmost point and the electric current injector that are arranged in grounded screen, the utmost point that wherein refluxes is connected by driving source with electric current injector, and potential pole is connected with current potential control pin by digital oscilloscope, and current potential control pin is used for measuring potential value;
Described driving source comprises that signal generation divides, the output that signal generation divides divides two-way, one tunnel is connected with frequency display circuit, another road is connected with power amplifying part, the input of power amplifying part is connected with impedance transformer, and the output of impedance transformer divides two-way, and a road is connected with grounded screen load, another road is connected with output current display circuit, and signal generation divides with power amplifying part is powered by power supply.
Described signal generation divides and comprises regulating and controlling circuit, and regulating and controlling circuit and signal circuit for generating is connected, and signal generating circuit is connected with amplification output stage;
Described power amplifying part comprises input stage, and input stage is connected with promotion level, promotes level and is connected with output stage, and output stage is connected with the input end of protected level, and the output terminal of protected level is connected with input stage and promotion grade.
The CDEGS of simulation software is the tool software that is solved the engineering problems such as electric system ground connection, electromagnetic field and electromagnetic interference (EMI) by the exploitation of Canadian SES company, can calculate and analyze various earthed system parameters, for example surface potential, touch voltage, step voltage, impedance ground, fault current distribution.Purposes in electric system is very extensive.Can utilize the MALZ module of ground connection simulation software the inside to carry out emulation to grounded screen.
Beneficial effect of the present invention:
The fault of grounded screen has been the important hidden danger of safe operation of power system, should set up a set of method that grounded screen is diagnosed for this reason.The quality of Grounding performance is directly connected to staff's personal safety and the safety of various electrical equipments and normally operation in transformer station, and therefore grounded screen being detected is to manufacturer or user has positive meaning.This project has been invented a kind of new grounded screen inventive method, do not need large area to excavate grounded screen, avoided a large amount of human and material resources, the waste of financial resources, be not also subject to the restriction of on-the-spot service condition simultaneously, ensure that electric system normally moves, be with a wide range of applications and marketable value.
Brief description of the drawings
Fig. 1 schematic flow sheet of the present invention;
Fig. 2 electric current method for implanting schematic diagram;
Fig. 3 Plant arrangement figure of the present invention;
The cut-away drawing of Fig. 4 driving source;
In figure, 1, potential pole, 2, grounded screen, 3, electric current injector, 4, the backflow utmost point, 5, driving source, 6, current potential control pin, 7, digital oscilloscope.
Embodiment:
Below in conjunction with accompanying drawing, the present invention is described in detail:
The present invention need not consider electric current decanting point, extract the position of point out, can need the position of selecting arbitrarily decanting point, extracting point out according to scene.
As shown in Figure 1, a kind of method of corrosion diagnosis of grounding grid, comprises the following steps:
Step 1: to grounded screen 2 injected frequencies and the big or small simple sinusoidal alternating current that differs from the optional frequency of 50Hz; After Injection Current, on each earth conductor, there is electric current to flow through, have current potential and produce.
Step 2: utilize current potential control pin 6 to measure observation station potential rise and with reference to bus supply voltage, observation station spreads all over whole grounded screen 2, as far as possible potential rise point-blank of choosing and with reference to bus supply voltage; Be convenient for measuring, measurement data is convenient to form straight line, convenient and emulated data is compared.
Step 3: the reference power source busbar voltage number percent of calculating observation point; Reduce error, prevent from affecting larger because only survey the current potential scene that is subject to.
Step 4: utilize simulation software to carry out emulation to intact grounded screen, calculating observation point reference power source busbar voltage number percent; In order to form contrast with actual measured value.
Step 5: liken the reference voltage percentage of actual spot of measurement reference voltage number percent and simulation software calculating to difference;
Step 6: whether the reference power source busbar voltage percentage difference that judges observation point meets pre-conditioned, in the time of reference voltage percentage difference≤1, do not corrode, in the time of reference voltage percentage difference≤5, slight corrosion, in the time of reference voltage percentage difference ﹥ 5, heavy corrosion.
As shown in Figure 2, in described step 1, the position of Injection Current, size are not limited by field condition, do not need to excavate electrical network.
In described step 2, the welcome selection of observation station, can measure successively along a direction.
The reference power source busbar voltage number percent of observation point is exactly that the potential rise of observation station is divided by the potential rise of electric current decanting point.
As shown in Figure 3-4, a kind of corrosion diagnosis of grounding grid device, comprise the potential pole 1, the backflow utmost point 4 and the electric current injector 3 that are arranged in grounded screen 2, the utmost point 4 that wherein refluxes is connected by driving source 5 with electric current injector 3, potential pole 1 is connected with current potential control pin 6 by digital oscilloscope 7, and current potential control pin 6 is for measuring potential value;
Described driving source 5 comprises that signal generation divides, the output that signal generation divides divides two-way, one tunnel is connected with frequency display circuit, another road is connected with power amplifying part, the input of power amplifying part is connected with impedance transformer, and the output of impedance transformer divides two-way, and a road is connected with grounded screen load, another road is connected with output current display circuit, and signal generation divides with power amplifying part is powered by power supply.
Described signal generation divides and comprises regulating and controlling circuit, and regulating and controlling circuit and signal circuit for generating is connected, and signal generating circuit is connected with amplification output stage;
Described power amplifying part comprises input stage, and input stage is connected with promotion level, promotes level and is connected with output stage, and output stage is connected with the input end of protected level, and the output terminal of protected level is connected with input stage and promotion grade.
The CDEGS of simulation software is the tool software that is solved the engineering problems such as electric system ground connection, electromagnetic field and electromagnetic interference (EMI) by the exploitation of Canadian SES company, can calculate and analyze various earthed system parameters, for example surface potential, touch voltage, step voltage, impedance ground, fault current distribution.Purposes in electric system is very extensive.Can utilize the MALZ module of ground connection simulation software the inside to carry out emulation to grounded screen.
Table 1 extent of corrosion judge module
Claims (10)
1. a method for corrosion diagnosis of grounding grid, is characterized in that, comprises the following steps:
Step 1: to grounded screen injected frequency and the big or small simple sinusoidal alternating current that differs from the optional frequency of 50Hz;
Step 2: utilize measurement mechanism measure observation station potential rise and with reference to bus supply voltage;
Step 3: the reference power source busbar voltage number percent that calculates actual observation point;
Step 4: utilize simulation software to carry out emulation to intact grounded screen, utilize simulation software calculating observation point reference power source busbar voltage number percent;
Step 5: the reference voltage percentage of actual observation being put to reference voltage number percent and simulation software calculating likens difference to;
Step 6: whether the reference power source busbar voltage percentage difference that judges observation point meets pre-conditioned.
2. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1, is characterized in that, in described step 2, described measurement mechanism is current potential control pin.
3. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1, is characterized in that, in described step 2, described observation station spreads all over whole grounded screen.
4. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1, is characterized in that, in described step 3, the potential rise that reference power source busbar voltage number percent is observation station is multiplied by 100% divided by the potential rise of electric current decanting point.
5. the method for a kind of corrosion diagnosis of grounding grid as described in claim 1 or 3, is characterized in that, selects potential rise point-blank and with reference to bus supply voltage when described observation station is measured.
6. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1, it is characterized in that, in described step 6, when judgement: in the time of reference voltage percentage difference≤1, do not corrode, in the time of reference voltage percentage difference≤5, slightly corrosion, in the time of reference voltage percentage difference ﹥ 5, heavy corrosion.
7. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1, is characterized in that, described simulation software is CDEGS simulation calculation software.
8. the method for a kind of corrosion diagnosis of grounding grid as claimed in claim 1 device used, it is characterized in that, comprise the potential pole, the backflow utmost point and the electric current injector that are arranged in grounded screen, the utmost point that wherein refluxes is connected by driving source with electric current injector, potential pole is connected with current potential control pin by digital oscilloscope, and current potential control pin is used for measuring potential value;
Described driving source comprises that signal generation divides, the output that signal generation divides divides two-way, one tunnel is connected with frequency display circuit, another road is connected with power amplifying part, the input of power amplifying part is connected with impedance transformer, and the output of impedance transformer divides two-way, and a road is connected with grounded screen load, another road is connected with output current display circuit, and signal generation divides with power amplifying part is powered by power supply.
9. device as claimed in claim 8, is characterized in that, described signal generation divides and comprises regulating and controlling circuit, and regulating and controlling circuit and signal circuit for generating is connected, and signal generating circuit is connected with amplification output stage.
10. device as claimed in claim 8, is characterized in that, described power amplifying part comprises input stage; input stage is connected with promotion level; promote level and be connected with output stage, output stage is connected with the input end of protected level, and the output terminal of protected level is connected with input stage and promotion level.
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104777402A (en) * | 2015-04-10 | 2015-07-15 | 国家电网公司 | Corrosion state diagnosis and prevention method for grounding grid |
| CN104897995A (en) * | 2015-06-10 | 2015-09-09 | 国网上海市电力公司 | Transformer station grounding network corrosion detecting system based on earth surface potential, and method thereof |
| CN104931853A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Diagnosis method for transformer-station grounding net based on surface potential distribution |
| CN104965134A (en) * | 2015-06-10 | 2015-10-07 | 国网上海市电力公司 | Echo state network-based transformer station grounding grid earth surface potential distribution calculation method |
| CN105279342A (en) * | 2015-11-18 | 2016-01-27 | 广州地铁集团有限公司 | Segmenting method for subway contact system lead, system, simulating method and simulating system |
| CN105652139A (en) * | 2015-12-30 | 2016-06-08 | 国家电网公司 | Method for testing conductivity of grounding grid |
| CN106093534A (en) * | 2016-08-08 | 2016-11-09 | 三峡大学 | A kind of method testing earth mat step voltage and contact voltage |
| CN110794216A (en) * | 2019-11-14 | 2020-02-14 | 云南电网有限责任公司西双版纳供电局 | Grounding state detection device and detection method thereof |
| CN110907344A (en) * | 2019-11-18 | 2020-03-24 | 深圳供电局有限公司 | Grounding grid corrosion rate detection system |
| CN110907343A (en) * | 2019-11-18 | 2020-03-24 | 深圳供电局有限公司 | Method for detecting corrosion rate of grounding grid |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01111369A (en) * | 1987-10-26 | 1989-04-28 | Nec Ic Microcomput Syst Ltd | Cmos type integrated circuit device |
| JP2006115555A (en) * | 2004-10-12 | 2006-04-27 | Koichi Tsuji | Ground directional relay |
| CN201138368Y (en) * | 2007-12-28 | 2008-10-22 | 华北电力大学 | Defect diagnostic equipment for substation grounding grid |
| CN201886113U (en) * | 2010-12-14 | 2011-06-29 | 四川电力试验研究院 | Pilot-frequency and high-current multifunctional grounding parameter testing system based on variable frequency power supply |
| CN202119699U (en) * | 2011-04-27 | 2012-01-18 | 北京工业大学 | Corrosion detection device of grounding net conductor based on SH0 wave power system |
| CN102435918A (en) * | 2011-09-14 | 2012-05-02 | 浙江省电力试验研究院 | Large-current outdoor real model simulation test method for testing lightning impulse characteristics of grounding device |
| CN102495291A (en) * | 2011-12-13 | 2012-06-13 | 武汉大学 | Impedance frequency response method for measuring corrosion state of grounding network of transformer substation |
| CN102928704A (en) * | 2012-10-26 | 2013-02-13 | 湖州电力局 | Intelligent diagnosis method for corrosion failure point of transformer substation grounding grid |
| CN202903922U (en) * | 2012-10-26 | 2013-04-24 | 湖州电力局 | Corrosion fault point diagnosis system for substation grounding grids |
| CN103197193A (en) * | 2013-03-25 | 2013-07-10 | 重庆市电力公司电力科学研究院 | Method and system for determining grounding grid corrosion point |
-
2014
- 2014-03-17 CN CN201410098954.0A patent/CN103837775A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01111369A (en) * | 1987-10-26 | 1989-04-28 | Nec Ic Microcomput Syst Ltd | Cmos type integrated circuit device |
| JP2006115555A (en) * | 2004-10-12 | 2006-04-27 | Koichi Tsuji | Ground directional relay |
| CN201138368Y (en) * | 2007-12-28 | 2008-10-22 | 华北电力大学 | Defect diagnostic equipment for substation grounding grid |
| CN201886113U (en) * | 2010-12-14 | 2011-06-29 | 四川电力试验研究院 | Pilot-frequency and high-current multifunctional grounding parameter testing system based on variable frequency power supply |
| CN202119699U (en) * | 2011-04-27 | 2012-01-18 | 北京工业大学 | Corrosion detection device of grounding net conductor based on SH0 wave power system |
| CN102435918A (en) * | 2011-09-14 | 2012-05-02 | 浙江省电力试验研究院 | Large-current outdoor real model simulation test method for testing lightning impulse characteristics of grounding device |
| CN102495291A (en) * | 2011-12-13 | 2012-06-13 | 武汉大学 | Impedance frequency response method for measuring corrosion state of grounding network of transformer substation |
| CN102928704A (en) * | 2012-10-26 | 2013-02-13 | 湖州电力局 | Intelligent diagnosis method for corrosion failure point of transformer substation grounding grid |
| CN202903922U (en) * | 2012-10-26 | 2013-04-24 | 湖州电力局 | Corrosion fault point diagnosis system for substation grounding grids |
| CN103197193A (en) * | 2013-03-25 | 2013-07-10 | 重庆市电力公司电力科学研究院 | Method and system for determining grounding grid corrosion point |
Non-Patent Citations (2)
| Title |
|---|
| 刘冉等: "CDEGS在接地网缺陷诊断中的应用研究", 《机电一体化》, no. 6, 31 December 2013 (2013-12-31) * |
| 刘洋等: "应用阻抗变换技术的变电站接地网检测系统激励源的设计与应用", 《中国电机工程学报》, vol. 28, no. 28, 5 October 2008 (2008-10-05) * |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104777402A (en) * | 2015-04-10 | 2015-07-15 | 国家电网公司 | Corrosion state diagnosis and prevention method for grounding grid |
| CN104931853A (en) * | 2015-06-08 | 2015-09-23 | 上海交通大学 | Diagnosis method for transformer-station grounding net based on surface potential distribution |
| CN104931853B (en) * | 2015-06-08 | 2017-12-12 | 上海交通大学 | A kind of grounding net of transformer substation corrosion diagnosis method based on surface potential distribution |
| CN104965134B (en) * | 2015-06-10 | 2017-11-03 | 国网上海市电力公司 | Grounding net of transformer substation surface potential distribution calculation method based on echo state network |
| CN104897995A (en) * | 2015-06-10 | 2015-09-09 | 国网上海市电力公司 | Transformer station grounding network corrosion detecting system based on earth surface potential, and method thereof |
| CN104965134A (en) * | 2015-06-10 | 2015-10-07 | 国网上海市电力公司 | Echo state network-based transformer station grounding grid earth surface potential distribution calculation method |
| CN104897995B (en) * | 2015-06-10 | 2019-04-26 | 国网上海市电力公司 | Grounding net of transformer substation corrosion detection system and method based on surface potential |
| CN105279342A (en) * | 2015-11-18 | 2016-01-27 | 广州地铁集团有限公司 | Segmenting method for subway contact system lead, system, simulating method and simulating system |
| CN105279342B (en) * | 2015-11-18 | 2019-01-04 | 广州地铁设计研究院股份有限公司 | The segmentation method and system of subway contact line conducting wire, emulation mode and system |
| CN105652139A (en) * | 2015-12-30 | 2016-06-08 | 国家电网公司 | Method for testing conductivity of grounding grid |
| CN106093534A (en) * | 2016-08-08 | 2016-11-09 | 三峡大学 | A kind of method testing earth mat step voltage and contact voltage |
| CN110794216A (en) * | 2019-11-14 | 2020-02-14 | 云南电网有限责任公司西双版纳供电局 | Grounding state detection device and detection method thereof |
| CN110794216B (en) * | 2019-11-14 | 2022-01-18 | 云南电网有限责任公司西双版纳供电局 | Grounding state detection device and detection method thereof |
| CN110907344A (en) * | 2019-11-18 | 2020-03-24 | 深圳供电局有限公司 | Grounding grid corrosion rate detection system |
| CN110907343A (en) * | 2019-11-18 | 2020-03-24 | 深圳供电局有限公司 | Method for detecting corrosion rate of grounding grid |
| CN110907344B (en) * | 2019-11-18 | 2023-01-24 | 深圳供电局有限公司 | Grounding grid corrosion rate detection system |
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Application publication date: 20140604 |