CN105044505A - Grounding grid DC shunt coefficient measuring method based on high-power DC power supply - Google Patents
Grounding grid DC shunt coefficient measuring method based on high-power DC power supply Download PDFInfo
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- CN105044505A CN105044505A CN201510397259.9A CN201510397259A CN105044505A CN 105044505 A CN105044505 A CN 105044505A CN 201510397259 A CN201510397259 A CN 201510397259A CN 105044505 A CN105044505 A CN 105044505A
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Abstract
The present invention relates to a grounding grid DC shunt coefficient testing method and more particularly to a grounding grid DC shunt coefficient measuring method based on a high-power DC power supply. The method comprises the steps of (1) injecting high-power DC testing current Ir in any grounding downlead line position of a grounding grid to be measured, defining the direction that the testing current goes into a ground as a positive direction, (2) obtaining the shunt current value Ik of the position, and (3) carrying out individual measurement to obtain the shunt condition In of each line out frame of the ground grid or a cable and summing all algebraic sums with current to obtain the shunt condition of the whole grounding grid. According to the method, the high-power DC power supply is used to provide current, the interference of a working frequency signal can be avoided, the adding and subtraction of mold values can be directly carried out after the positive direction is defined, and the complication and trouble of the phase measurement of other methods are avoided.
Description
Technical field
The present invention relates to grounded screen diverting coefficient method of testing, particularly relate to a kind of grounded screen diverting coefficient measuring method based on high-power DC power supply, belong to electric system grounded screen characterisitic parameter fields of measurement.
Background technology
Grounding net of transformer substation is as the special ingredient of electric system; a kind of current by pass is provided during except breaking down as transformer station; the safety of protection station equipment and operations staff; also for other equipment provides working earthing; according to relevant regulations stipulate, certain time limit is needed to carry out preventive trial to the parameter of grounded screen.Stake resistance, as one of important characteristic parameter of grounded screen, is measured as an important parameter in preventative examination.
Stake resistance is defined as the resistance value of earthing device to distant place zero potential point.In current test procedure, generally on grounding net of transformer substation downlead, inject an alien frequencies small area analysis I or power frequency heavy-current I, then measure the voltage difference U between grounded screen and the voltage level of a distance with voltage table, obtain the apparent impedance value of grounded screen, be defined as R=U/I; Resistance of Grounding Grids value is finally obtained by repetitive measurement.As can be seen here, the electric current I measuring accurately and obtain ground and voltage U between grounding net of transformer substation and voltage pole is only had could finally to obtain grounding resistance accurately, at present along with the development of technology, the precision of reometer and voltage table is all higher, the main source of error of measurement and the tapping condition of grounded screen.
Transformer station to be constituted on electrically by overhead transmission line or cable and other transformer stations after putting into operation and contacts, now in measuring process to grounding net of transformer substation Injection Current to be measured, now electric current not all flow into the earth by measuring grounded screen, flow into infinite point, but pass through the screen layer of lightning conducter or cable, the earth is flowed into by other transformer stations, now measure the electric current obtained and will be injected the size of current of the earth by transformer station to be measured than reality, cause measuring the magnitude of voltage obtained less than normal, and adopt during actual computation be measure electric current, finally cause grounding resistance less than normal than actual value.
For solving Problems existing in above-mentioned reality, Measurement accuracy is needed to obtain earth current.Now can be connected with every other transformer station lightning conducter or cable by disconnecting grounding net of transformer substation to be measured, making to measure electric current and all entering the earth, but when being connected by cable actually, cannot disconnect; Equally very difficult when being connected by lightning conducter, except newly put into operation transformer station when capital construction except, other run transformer stations and substantially cannot realize.In addition, by measuring the tapping condition of lightning conducter or cable, the real electric current flowing into the earth can also be obtained.When being undertaken by this kind of mode, because there is certain inductance in this province of grounded screen, there is certain inductance and electric capacity in coupled lightning conducter, in fact an impedance network is constituted, need when measuring to consider that phase place is on the impact of test result, directly carry out the measurement of phase place, implement like this and all have certain difficulty.
Patent of the present invention injects a galvanic current stream source by high-power DC power supply to grounding net of transformer substation, avoid the coupled lightning conducter of grounded screen, the impact of resistance value that cable is formed, directly carry out the measurement of resistance, now directly can add and subtract mutually current value and calculate, finally obtain the diverting coefficient of grounded screen.
Summary of the invention
Object of the present invention mainly for improving the measurement accuracy of transformer station, station grounding net stake resistance, provides a kind of method of testing of the grounded screen diverting coefficient based on high-power DC power supply.The method can make full use of the characteristic of DC current, avoids the difficulty of power frequency or non-power-frequency current phase measurement.
Essence of the present invention utilizes direct current without the characteristic of phase place, utilizes high-power DC power supply, injects a DC current to grounded screen to be measured, and keep stable in whole test process; Measure the direct current flow of all overhead ground wires or cable outflow simultaneously, the diverting coefficient of grounded screen can be obtained.
The present invention, according to above-mentioned know-why, provides a kind of grounded screen diverting coefficient measuring method based on high-power DC power supply, it is characterized in that, comprise the steps:
The first step, injects a high power DC measuring current Ir in any down conductor position of grounded screen to be measured, and keep current stabilization in test process, define this measuring current enter ground direction be positive dirction;
Second step, utilizes high-precision current table to vise the down conductor of certain cable or circuit outlet structure in this ground web area, and is positive dirction down by the measurement direction of reometer, compared with the magnitude of current in the first step, be the partial current value Ik of this position;
3rd step, adopts the method identical with second step, measures the tapping condition In obtaining each circuit outlet structure of earth mat or cable one by one, the algebraic sum of all electric currents is added, obtains the tapping condition of whole grounded screen.
Preferably, described grounded screen refers to the grounded screen of transformer station, generating plant, current conversion station.
Preferably, the transmission line of electricity that described grounded screen is connected with other transformer stations, generating plant, current conversion station is provided with lightning conducter.
In a preference of the present invention, in second step, the resolution of reometer should reach 0.01A.
In a preference of the present invention, the DC test electric current injected in a first step is greater than 5A; It is generally acknowledged that the shunting test data of every root lightning conducter is more than 10 times of reometer resolution, reliable measuring data degree is higher; According to test case, a lightning conducter shunting is large about about 2%, and when measurement reometer resolution is 0.01A, the DC test electric current of injection is greater than 5A, and reliable measuring data degree is higher.
The present invention has technique effect positive as follows: adopt high-power DC power supply to provide measuring current, the interference of power frequency component can be avoided, directly can carry out the plus-minus of modulus value after defining positive dirction, avoid and adopt the loaded down with trivial details and difficult of additive method phase measurement.
Accompanying drawing explanation
Fig. 1 is grounded screen diverting coefficient of the present invention test schematic diagram.
1. ground; 2. grounded screen; 3. overhead ground wire; 4. framework down conductor; 5. any down conductor pulse current injectingt position.
Embodiment
Below by embodiment, by reference to the accompanying drawings, to technical scheme of the present invention, it is further described:
See Fig. 1, the first step, inject a high power DC measuring current Ir in any down conductor position of grounded screen to be measured, and keep current stabilization in test process, define this measuring current enter ground direction be positive dirction; High power DC current flow devices adopts certain plant equipment of customization, and can provide the DC current of maximum 100A, in implementation process, warranty test current stabilization is at 50A, and injection phase is positioned at this transformer station 1# main transformer place.
Second step, utilizes high-precision current table to vise the down conductor of certain cable or circuit outlet structure in this ground web area, and is positive dirction down by the measurement direction of reometer, compared with the magnitude of current in the first step, be the partial current value Ik of this position; During measurement, reometer adopts FULKE345, and during measurement, equipment keeps electric current to enter place to being positive dirction.In this transformer station by 3 500kV circuits and power plant's contact, article 2,500kV circuit and transformer station's contact, article 1,110kV circuit and transformer station's contact, measure 110kV circuit framework down conductor in implementation process, measured value is-0.81A.
3rd step, adopts the method identical with second step, measures the tapping condition In obtaining each circuit outlet structure of earth mat or cable one by one, the algebraic sum of all electric currents is added, obtains the tapping condition of whole grounded screen.In implementation process, the down conductor of all overhead transmission line frameworks all except second step is measured.Comprise second step to measure, all down conductor measurement results are-13.35A.Thus the diverting coefficient that can obtain the outflow of this grounding net of transformer substation is 26.7%, the diverting coefficient entering ground from transformer station is 73.3%.
Conventional alien frequencies method is adopted to measure the tapping condition that same transformer station flows out, Injection Current is at 6.40A, frequency is 47HZ, this equipment can not measure phase angle, the diverting coefficient that the way adopting modulus value to be added obtains the outflow of this grounding net of transformer substation is 38.9%, the diverting coefficient entering ground from transformer station is 61.1%, if according to said method convert to the stake resistance of this transformer station, by causing, final grounding resistance measurement result is bigger than normal.
Adopt said method, obtain the diverting coefficient of grounding net of transformer substation, avoid Hz noise, the numerical value that can directly utilize test to obtain is added, and facilitates field conduct.
The above embodiment of the present invention is not limiting the scope of the present invention; embodiments of the present invention are not limited thereto; according to foregoing of the present invention; according to ordinary technical knowledge and the customary means of this area; do not departing under the present invention's above-mentioned basic fundamental thought prerequisite; to the amendment of other various ways that said structure of the present invention is made, replacement or change, all drop within protection scope of the present invention.
Claims (5)
1., based on a grounded screen diverting coefficient measuring method for high-power DC power supply, it is characterized in that, comprise the steps:
The first step, injects a high power DC measuring current Ir in any down conductor position of grounded screen to be measured, and keep current stabilization in test process, define this measuring current enter ground direction be positive dirction;
Second step, utilizes high-precision current table to vise the down conductor of certain cable or circuit outlet structure in this ground web area, and is positive dirction down by the measurement direction of reometer, compared with the magnitude of current in the first step, be the partial current value Ik of this position;
3rd step, adopts the method identical with second step, measures the tapping condition In obtaining each circuit outlet structure of earth mat or cable one by one, the algebraic sum of all electric currents is added, obtains the tapping condition of whole grounded screen.
2. the earth mat diverting coefficient measuring method based on high power DC electric current according to claim 1, is characterized in that described grounded screen refers to the grounded screen of transformer station, generating plant, current conversion station.
3. the grounded screen diverting coefficient measuring method based on high power DC electric current according to claim 1, is characterized in that the electric transmission line erection that described grounded screen is connected with other transformer stations, generating plant, current conversion station has lightning conducter.
4. according to any one of claim 1-3 based on high power DC current earthing net diverting coefficient method of testing, it is characterized in that the resolution of reometer in second step should reach 0.01A.
5. according to any one of claim 1 based on high power DC current earthing net diverting coefficient method of testing, it is characterized in that the DC test electric current injected in the first step is greater than 5A.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105388355A (en) * | 2015-12-03 | 2016-03-09 | 国家电网公司 | Ground screen shunting vector test system and method with GPS synchronization |
| CN106950456A (en) * | 2017-05-26 | 2017-07-14 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method tested based on man-made short-circuit |
| CN107132455A (en) * | 2017-05-26 | 2017-09-05 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method injected based on ground line current |
| CN108646077A (en) * | 2018-05-02 | 2018-10-12 | 中铁第四勘察设计院集团有限公司 | The ground connection parameter acquiring method and device of traction substation |
| CN112362942A (en) * | 2020-10-20 | 2021-02-12 | 国网湖北省电力有限公司电力科学研究院 | Rail transit feed current measuring method based on shunt coefficient |
| CN115166338A (en) * | 2022-08-09 | 2022-10-11 | 国网湖南省电力有限公司 | Hydropower station ground grid shunt vector testing method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2791655Y (en) * | 2005-05-27 | 2006-06-28 | 福建省电力试验研究所 | Earthing network state monitoring system |
| JP2008263761A (en) * | 2007-04-13 | 2008-10-30 | Chugoku Electric Power Co Inc:The | Power line artificial ground fault testing system and method |
| CN103217584A (en) * | 2013-03-26 | 2013-07-24 | 广东电网公司电力科学研究院 | Method for measuring ground impedance of large grounding grid |
| CN104569671A (en) * | 2014-12-30 | 2015-04-29 | 云南电网公司电力科学研究院 | Method for testing direct current shunting coefficient of grounding grid of convertor station |
-
2015
- 2015-07-09 CN CN201510397259.9A patent/CN105044505A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2791655Y (en) * | 2005-05-27 | 2006-06-28 | 福建省电力试验研究所 | Earthing network state monitoring system |
| JP2008263761A (en) * | 2007-04-13 | 2008-10-30 | Chugoku Electric Power Co Inc:The | Power line artificial ground fault testing system and method |
| CN103217584A (en) * | 2013-03-26 | 2013-07-24 | 广东电网公司电力科学研究院 | Method for measuring ground impedance of large grounding grid |
| CN104569671A (en) * | 2014-12-30 | 2015-04-29 | 云南电网公司电力科学研究院 | Method for testing direct current shunting coefficient of grounding grid of convertor station |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105388355A (en) * | 2015-12-03 | 2016-03-09 | 国家电网公司 | Ground screen shunting vector test system and method with GPS synchronization |
| CN106950456A (en) * | 2017-05-26 | 2017-07-14 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method tested based on man-made short-circuit |
| CN107132455A (en) * | 2017-05-26 | 2017-09-05 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method injected based on ground line current |
| CN107132455B (en) * | 2017-05-26 | 2019-07-05 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method based on ground line current injection |
| CN106950456B (en) * | 2017-05-26 | 2019-07-26 | 云南电网有限责任公司电力科学研究院 | A kind of grounding net of transformer substation performance estimating method based on man-made short-circuit's experiment |
| CN108646077A (en) * | 2018-05-02 | 2018-10-12 | 中铁第四勘察设计院集团有限公司 | The ground connection parameter acquiring method and device of traction substation |
| CN112362942A (en) * | 2020-10-20 | 2021-02-12 | 国网湖北省电力有限公司电力科学研究院 | Rail transit feed current measuring method based on shunt coefficient |
| CN115166338A (en) * | 2022-08-09 | 2022-10-11 | 国网湖南省电力有限公司 | Hydropower station ground grid shunt vector testing method |
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