CN107728024A - A kind of large-scale grounding network impact characteristics method of testing to be flowed back using earth mat - Google Patents
A kind of large-scale grounding network impact characteristics method of testing to be flowed back using earth mat Download PDFInfo
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- CN107728024A CN107728024A CN201711021516.4A CN201711021516A CN107728024A CN 107728024 A CN107728024 A CN 107728024A CN 201711021516 A CN201711021516 A CN 201711021516A CN 107728024 A CN107728024 A CN 107728024A
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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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
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Abstract
The invention discloses a kind of large-scale grounding network impact characteristics method of testing to be flowed back using earth mat, including：Select the position of Current injection points and current reflux point, the positive pole of Current injection points connection impact power supply, the negative pole of current reflux point connection impact power supply on the net on ground；Voltage reference points are selected on the line of Current injection points and current reflux point；During using high-voltage probe measurement dash current injection earth mat, the potential difference between Current injection points and voltage reference points, the impact ground potential liter of the peak value, as decanting point of reading potential difference；Use the peak value of current probe measurement dash current；The Transient grounding resistance with Current calculation earth mat is risen according to impact ground potential.Current reflux pole is arranged on earth mat to be measured by the present invention, without laying current reflux pole again outside earth mat to be measured, reduces the impedance in loop, is convenient for the detection of grounded screen impact characteristics.
Description
Technical field
The present invention relates to technical field of high voltage, more particularly to a kind of large-scale grounding network impact characteristics to be flowed back using earth mat
Method of testing.
Background technology
, often need to be by power system and its some parts of electrical equipment in order to work and security needs in power system
With being greatly connected, here it is ground connection.Transformer station is grounded to ensure reliable ground, it is necessary in transformer station's embedded underground grounded screen
The size of net can be suitable with the area of transformer station.
At present, the leading indicator for examining grounded screen performance is the power frequency earthing resistance of grounded screen, and related detecting method is
It is very perfect, need in practice to the newly-built grounded screen progress power frequency earthing resistance measurement into earth mat and using a period of time, root
The performance of grounded screen is evaluated according to the size of power frequency earthing resistance.
Shorted to earth failure and thunderbolt are accidents common in power system, inject the generally height in grounded screen during thunderbolt
Dash current based on frequency composition.The impact characteristics of grounded screen have bigger difference with power frequency characteristic, under impact, due to earth conductor
Inductive effect, dash current is difficult in ground uniform diffusing on the net, but concentrates on the earth conductor near Current injection points
Diffusing, the effective area of diffusing are smaller.Therefore, under dash current injection, occur between decanting point and the other regions of grounded screen
Great transient state potential difference.Ultra-high voltage transformer station grounded screen catercorner length newly-built at present typically can reach hundreds of meters, so
The grounded screen power frequency earthing resistance of large area often very little.However, because the problem of effective area be present in dash current diffusing, i.e.,
Make the power frequency earthing resistance very little of grounded screen, under dash current injection, still may cause the impact transient state ground potential liter of danger.
Therefore, it is quite necessary to examine the impact characteristics of grounded screen.However, seldom the impact characteristics of grounded screen are carried out in engineering at present
Investigate, this undoubtedly leaves larger potential safety hazard.
《DL/T 266-2012 earthing or grounding means impact characteristics parameter testing directive/guides》With reference to power frequency characteristic measurement method, there is provided
The method of measurement earthing or grounding means impact characteristics, this method is traditional three electrode method, as shown in Figure 1.According to DL/T 266-2012
It is required that current reflux pole (label C in Fig. 1) should be apart from ground 2~3D of network edge (D is earthing or grounding means maximum diagonal length).It is small
Type earthing or grounding means catercorner length is smaller, is easier to meet the requirement.But ultra-high voltage transformer station grounded screen catercorner length is reachable
Hundreds of meters, meet that the reflux point position of requirement is often outer at one kilometer even several kilometers.Dash current caused by impact test
General amplitude is higher, and current feed needs to select blister copper wire, arranges that current feed is more difficult over long distances, work on the spot amount is huge
Greatly；And long lead has larger inductance, there is larger obstruction to dash current.Meanwhile the backflow pole of laying is due to existing
Field condition limitation can only simple-arranged, grounding resistance is very big.The inductance of long lead and the grounding resistance of backflow pole cause whole return
Roadlock resists larger, seriously limits the dash current amplitude of output, and can Severe distortion dash current waveform, cannot accord with
Close desired dash current.
The content of the invention
Weak point present in regarding to the issue above, the present invention provide a kind of large-scale grounding network using earth mat backflow and rushed
Hit characteristic test method.
To achieve the above object, the present invention provides a kind of large-scale grounding network impact characteristics test side to be flowed back using earth mat
Method, including：
Step 1, the position for selecting on ground Current injection points and current reflux point on the net, Current injection points connection impact power supply
Positive pole, current reflux point connection impact power supply negative pole；
Step 2, select voltage reference points on the line of Current injection points and current reflux point；
Step 3, using high-voltage probe measurement dash current injection earth mat when, between Current injection points and voltage reference points
Potential difference, the impact ground potential liter of the peak value, as decanting point of reading potential difference；
Step 4, the peak value using current probe measurement dash current；
Step 5, the Transient grounding resistance according to impact ground potential liter and Current calculation earth mat.
As a further improvement on the present invention, in step 1, Current injection points and the current reflux point is under grounding lead
Line, the distance between the Current injection points and current reflux point are more than 100m.
As a further improvement on the present invention, in step 2, the distance of Current injection points and the current reflux point is L,
The distance between the Current injection points and voltage reference points are 0.618L.
As a further improvement on the present invention, in step 3, the high-voltage probe just terminates Current injection points, the height
Pressure probe negative terminal connects voltage reference points by plain conductor, and the data connector of high-voltage probe connects oscillograph or data collecting card to remember
Record the waveform of the potential difference, the peak value Um, as decanting point of reading potential difference impact ground potential liter.
As a further improvement on the present invention, the peak I m of dash current is measured using current probe, is counted according to Um and Im
Calculate the Transient grounding resistance of earth mat.
As a further improvement on the present invention, in addition to：The measurement that ground potential near Current injection points rises；
During measurement, high-voltage probe is just being terminated on the down conductor near decanting point, and high-voltage probe negative terminal passes through metal
Wire power connection presses reference point.
Compared with prior art, beneficial effects of the present invention are：
Current reflux pole is arranged on earth mat to be measured by the present invention, without laying current reflux again outside earth mat to be measured
Pole, reduce the impedance in loop, be convenient for the detection of grounded screen impact characteristics；
The method of testing of the present invention only needs to lay about 100m current feed, substantially reduces measurement workload, while can
The influence of reflux point is compensated, makes measurement result more accurate.
Brief description of the drawings
Fig. 1 is the schematic diagram of existing three electrode method；
Fig. 2 is the disclosed large-scale grounding network impact characteristics method of testing using earth mat backflow of an embodiment of the present invention
Flow chart；
Fig. 3 is Current injection points disclosed in an embodiment of the present invention and current reflux point in the online layout drawing in ground；
Fig. 4 is the layout drawing of voltage reference points disclosed in an embodiment of the present invention.
Embodiment
To make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below in conjunction with the embodiment of the present invention
In accompanying drawing, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is
The part of the embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, ordinary skill people
The every other embodiment that member is obtained on the premise of creative work is not made, belongs to the scope of protection of the invention.
In the description of the invention, it is necessary to explanation, term " " center ", " on ", " under ", "left", "right", " vertical ",
The orientation or position relationship of the instruction such as " level ", " interior ", " outer " be based on orientation shown in the drawings or position relationship, merely to
Be easy to the description present invention and simplify description, rather than instruction or imply signified device or element must have specific orientation,
With specific azimuth configuration and operation, therefore it is not considered as limiting the invention.In addition, term " first ", " second ",
" the 3rd " is only used for describing purpose, and it is not intended that instruction or hint relative importance.
In the description of the invention, it is also necessary to explanation, unless otherwise clearly defined and limited, term " installation ",
" connected ", " connection " should be interpreted broadly, for example, it may be being fixedly connected or being detachably connected, or integratedly be connected
Connect；Can be mechanical connection or electrical connection；Can be joined directly together, can also be indirectly connected by intermediary, can
To be the connection of two element internals.For the ordinary skill in the art, above-mentioned term can be understood with concrete condition
Concrete meaning in the present invention.
The present invention is described in further detail below in conjunction with the accompanying drawings：
In fact, when dash current injects earth mat, dash current concentrates on decanting point and near zone diffusing.From decanting point
Outward, earth mat ground potential rises rapid decay, and this point is with being very different when the low frequency, therefore, for ultra-high voltage transformer station, time
Flow point and do not need standard in recommend it is so remote.Rational reflux point position even can in earth mat to be measured, now, by
Larger in the lower grounded screen longitudinal direction induction reactance of impact, most current diffusing enters ground, rather than passes through earth mat conductor flow telegram in reply source.Root
According to the thinking, a kind of large-scale grounding network impact characteristics method of testing to be flowed back using earth mat of the invention is proposed.
As shown in Fig. 2 the present invention provides a kind of large-scale grounding network impact characteristics method of testing to be flowed back using earth mat, by electricity
Streamer access point and current reflux point are arranged in earth mat to be measured simultaneously；Specifically include：
S101, as shown in figure 3, selecting Current injection points and current reflux point on earth mat to be measured (grid shown in Fig. 3)
Position, Current injection points are generally the down conductor of visual plant or lightning rod, and current reflux point selection is injected with electric current
Point has the down conductor of certain distance (more than 100m)；After the position of Current injection points and current reflux point is selected, it will impact
The positive pole connection Current injection points down conductor of power supply, the negative pole connection current reflux point down conductor of power supply is impacted, is led to
Overbump power supply produces dash current.
S102, as shown in figure 4, selecting voltage reference points on the line of Current injection points and current reflux point；Electric current is noted
Access point and the distance of current reflux point are L, and the distance between Current injection points and voltage reference points are 0.618L.
S103, using high-voltage probe measurement dash current injection earth mat when, between Current injection points and voltage reference points
Potential difference；High-voltage probe just terminates Current injection points, and high-voltage probe negative terminal connects voltage reference points, high-voltage probe by plain conductor
Data connector connect oscillograph or data collecting card to record the waveform of the potential difference, the peak value Um of reading potential difference, as note
The impact ground potential liter of access point.
S104, the peak I m using current probe measurement dash current；
S105, the Transient grounding resistance that Um and electric current Im calculates earth mat is risen according to impact ground potential.
The present invention can equally use the ground potential liter near high-voltage probe measurement decanting point；During measurement, high-voltage probe is just
Terminate on the down conductor near decanting point, high-voltage probe negative terminal connects voltage reference points by plain conductor.
Need to lay current reflux pole again outside earth mat to be measured different from traditional three electrode method, it is of the invention by current reflux
Pole is arranged on earth mat to be measured, without laying current reflux pole again outside earth mat to be measured, reduces the impedance in loop, be easy into
Row grounded screen impact characteristics detect；The method of testing of the present invention only needs to lay about 100m current feed, substantially reduces measurement
Workload, while the influence of reflux point is can compensate for, make measurement result more accurate.
For ultra-large type grounded screen, backflow pole also can be more nearby laid outside grounded screen, but the position for pole of flowing back is without same
The distance required in standard 2~3D of network edge it is so remote, it might even be possible to grounded screen edge lay backflow pole.
The preferred embodiments of the present invention are these are only, are not intended to limit the invention, for those skilled in the art
For member, the present invention can have various modifications and variations.Any modification within the spirit and principles of the invention, being made,
Equivalent substitution, improvement etc., should be included in the scope of the protection.
Claims (6)
- A kind of 1. large-scale grounding network impact characteristics method of testing to be flowed back using earth mat, it is characterised in that including：Step 1, the position for selecting on ground Current injection points and current reflux point on the net, Current injection points connection impact power supply is just Pole, the negative pole of current reflux point connection impact power supply；Step 2, select voltage reference points on the line of Current injection points and current reflux point；Step 3, using high-voltage probe measurement dash current injection earth mat when, the current potential between Current injection points and voltage reference points Difference, the impact ground potential liter of the peak value, as decanting point of reading potential difference；Step 4, the peak value using current probe measurement dash current；Step 5, the Transient grounding resistance according to impact ground potential liter and Current calculation earth mat.
- 2. the large-scale grounding network impact characteristics method of testing of earth mat backflow is utilized as claimed in claim 1, it is characterised in that In step 1, Current injection points and the current reflux point is down conductor, between Current injection points and the current reflux point Distance be more than 100m.
- 3. the large-scale grounding network impact characteristics method of testing of earth mat backflow is utilized as claimed in claim 1, it is characterised in that In step 2, the distance of Current injection points and the current reflux point is L, between the Current injection points and voltage reference points Distance is 0.618L.
- 4. the large-scale grounding network impact characteristics method of testing of earth mat backflow is utilized as claimed in claim 1, it is characterised in that In step 3, the high-voltage probe just terminates Current injection points, and the high-voltage probe negative terminal connects Voltage Reference by plain conductor Point, the data connector of high-voltage probe connect oscillograph or data collecting card to record the waveform of the potential difference, the peak of reading potential difference Value Um, as decanting point impact ground potential liter.
- 5. the large-scale grounding network impact characteristics method of testing of earth mat backflow is utilized as claimed in claim 4, it is characterised in that make With the peak I m of electric current probe measurement dash current, the Transient grounding resistance of earth mat is calculated according to Um and Im.
- 6. the large-scale grounding network impact characteristics method of testing of earth mat backflow is utilized as claimed in claim 1, it is characterised in that also Including：The measurement that ground potential near Current injection points rises；During measurement, high-voltage probe is just being terminated on the down conductor near decanting point, and high-voltage probe negative terminal passes through plain conductor Connect voltage reference points.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201711021516.4A CN107728024B (en) | 2017-10-27 | 2017-10-27 | Large-scale grounding grid impact characteristic testing method utilizing grounding grid backflow |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201711021516.4A CN107728024B (en) | 2017-10-27 | 2017-10-27 | Large-scale grounding grid impact characteristic testing method utilizing grounding grid backflow |
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| CN107728024A true CN107728024A (en) | 2018-02-23 |
| CN107728024B CN107728024B (en) | 2020-09-04 |
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Cited By (3)
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| CN108761175A (en) * | 2018-05-18 | 2018-11-06 | 云南电网有限责任公司电力科学研究院 | A kind of ground potential rises detecting system and transmission line lightning stroke situation determines method |
| CN109991468A (en) * | 2019-03-21 | 2019-07-09 | 中国电力科学研究院有限公司 | A kind of method and device for testing ultra-high voltage transformer station electrical secondary system disturbance voltage |
| CN110412355A (en) * | 2018-04-28 | 2019-11-05 | 武汉市康达电气有限公司 | A kind of earth loop impedance test instrument |
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| CN108761175B (en) * | 2018-05-18 | 2021-03-12 | 云南电网有限责任公司电力科学研究院 | Ground potential rise detection system and power transmission line lightning stroke condition determination method |
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