CN104569608A - Method for measuring impact grounding impedance on site based on large impact current - Google Patents
Method for measuring impact grounding impedance on site based on large impact current Download PDFInfo
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- CN104569608A CN104569608A CN201410770672.0A CN201410770672A CN104569608A CN 104569608 A CN104569608 A CN 104569608A CN 201410770672 A CN201410770672 A CN 201410770672A CN 104569608 A CN104569608 A CN 104569608A
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Abstract
The invention discloses a method for measuring impact grounding impedance on a site based on large impact current. The method comprises the following steps: wiring a current electrode, wiring an impact current generator, wiring an injection point voltage signal measuring wire, and wiring an injection point current signal measuring wire. By the method provided by the invention, a dispersing property of the impact current in soil can be really reflected, actual measurement on an impact grounding property of impedance under the large impact current can be achieved, the impact grounding impedance can be accurately measured, an impact property of a grounding body can be easily mastered, design, construction and running of lightning protection engineering can be instructed and inspected, the integral safety and the integral reliability of the engineering are improved, and the operability is good.
Description
Technical field
The present invention relates to a kind of impedance measurement method, be specifically related to a kind of based on the Transient grounding resistance on-site measurement method under heavy impulse current.
Background technology
Along with the fast development of national economy, the scale of electric line and electrified railway power supply system is increasing, structure becomes increasingly complex, in addition Climate and Environment Variation is abnormal in recent years, lightening activity is day by day frequent, therefore very pays close attention to thunderbolt jeopardizing security of system.The field such as power transmission and distribution and railway is constantly strengthened or is paid attention to Thunder Protection, and has dropped into the research that a large amount of manpower and financial resources carries out shocking preventing technology and measure.But lightning protection safety is not still solved, and technology or economy all exist larger deficiency, lightning protection measures specific aim is not strong, is still in single, extensive situation.Along with extra-high voltage grid and high-speed electric railway start to step into the high-speed developing period, the raising of electric pressure and shaft tower height and the further expansion of system scale, structure more complicated.Can predict, shocking preventing technology relatively lag behind and contradiction between the fast development of economy must solve as early as possible.
Thus, the Thunder Protection in the field such as power transmission and distribution and railway has very consequence, so how to reduce the important content that lightening hazard becomes security of system stable operation in the safe operation ensureing transmission and distribution network and the railway system.
Actual motion statistics shows, in the factor of the resistance to thunder security level of influential system, improving its impulse grounding characteristic is reduce lightning strike accident, improves the effective ways of safe operation reliability.At present in the design and construction of power transmission and distribution project, fall resistance measure and be mainly and adopt extended ground conductor, increase the measures such as ray radical, but these to fall resistance measure often unknown for the effect reducing impulse earthed resistance; And in railway engineering design and construction, often impulse grounding characteristic is not taken into account, the requirement whether the impulse grounding characteristic of natural grounding substance meets lightning Protection Design makes people uneasy.Therefore, be necessary to grasp its impulse grounding characteristic with the related data of the security of checking engineering lightning protection, propose coefficient of impact in conjunction with industrial frequency electric resistance interpretation of result, the engineering design and construction of Transient grounding resistance provide in time in order to reduce, science, reliably, foundation accurately.
Due to dash current through earthing device earial drainage time the complicacy of time-varying electric field that produces, be difficult to derive more accurate mathematic(al) representation theoretically, so the impact characteristics of earthing device can only be disclosed from the angle of in-site measurement.The impulse earthed resistance that general employing high-voltage pulse method is measured differs with true lightning impulse situation comparatively greatly, the result obtained under the impulse earthed resistance therefore measuring shaft tower can not reflect Practical Project situation.So, the actual result of engineering actual environment need be reduced, accurately to grasp its impact characteristics as far as possible.But field measurement is by such as needing to possess powerful dash current flow-generator and large actual measurement place, needs the restriction dropping into the conditions such as a large amount of manpower and materials, so mostly the research of Chinese scholars is theoretical research, being difficult to field measurement.
Therefore the basis need applied in above-mentioned test simulation research and actual measurement proposes a kind of impedance actual measurement device to realize the on-the-spot Measurement accuracy of impedance under large impact electric current.
Summary of the invention
For the deficiencies in the prior art, the invention provides a kind of on-site measurement method based on the Transient grounding resistance under heavy impulse current, measurement mechanism comprises earthing device, impulse current generator, Luo-coil, voltage divider, oscillograph and electric current pole; Described measuring method comprises the following steps:
A, the wiring of electric current pole: the round path being the center of circle with described earthing device is evenly arranged described electric current pole, to be extremely connected described electric current with braiding copper cash and to be connected to described impulse current generator body base;
B, the wiring of impulse current generator: draw braiding copper cash as current feed from the high-pressure side of described impulse current generator, and received the measurement decanting point place of described earthing device;
C, the measurement wiring of decanting point voltage signal: draw unsettled voltage lead at the measurement decanting point place of described earthing device, and be connected to the surge voltage signal that acquisition decanting point place sentenced by described voltage divider;
D, the measurement wiring of decanting point current signal: access described oscillograph at the collector ring place of described electric current pole by Luo-coil, described oscillographic other end stub cable is connected to described voltage divider.
Preferably, described electric current pole radical is no less than 8.
Preferably, the distance between the initial placement position of described electric current pole and the edge of described earthing device is 5m.
Preferably, described impulse current generator is moveable.
Preferably, described impulse current generator, described Luo-coil and described oscillograph all insulate with bottom surface.
Preferably, described impulse current generator, described oscillograph are independently-powered.
Preferably, the bus bar of described electric current pole disconnects at described voltage divider place.
Preferably, described voltage lead and the angle of current feed in space should be not less than 90 °.
Beneficial effect of the present invention is:
The present invention is based on great current impact test result of study and Study on Numerical Simulation result, propose a kind of on-site measurement method of the Transient grounding resistance based on heavy impulse current, the distribution situation of lightning current in soil can be reflected more really by this measuring method, can the Transient grounding resistance of Measurement accuracy grounding body.Measured result can check the design of grounding body whether to meet lightning protection requirement, and by surveying the impact of certain type grounding body, draw its coefficient of impact curve, only measure its power frequency earthing resistance in measuring at the scene in the future, in conjunction with existing coefficient of impact curve, just can calculate its Transient grounding resistance, contribute to the impact characteristics grasping grounding body, instruct and the design of checking engineering lightning protection, construction and operation, raising engineering overall security and reliability, have operability.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Fig. 1 is the wiring schematic diagram of the field measurement apparatus of the Transient grounding resistance that the present invention is based on heavy impulse current;
Fig. 2 is that current-voltage measurement loop angle in Fig. 1 of the present invention is to the effect diagram of measurement result.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
In order to thoroughly understand the embodiment of the present invention, by following description, detailed structure is proposed.Obviously, the execution of the embodiment of the present invention is not limited to the specific details that those skilled in the art has the knack of.Preferred embodiment of the present invention is described in detail as follows, but except these are described in detail, the present invention can also have other embodiments.
With reference to the wiring schematic diagram that Fig. 1, Fig. 1 are the field measurement apparatus of the Transient grounding resistance that the present invention is based on heavy impulse current.Measurement mechanism shown in figure comprises earthing device, mobile impulse current generator, Luo-coil, voltage divider, oscillograph and electric current pole composition; Described measuring method comprises the following steps:
A, the wiring of electric current pole: the round path being the center of circle with described earthing device is evenly arranged described electric current pole, then with braiding copper cash, described electric current is extremely connected, be finally connected to the base of described impulse current generator body; The arrangement that this dash current reclaims can reflect the diffusing distribution situation of lightning current in soil more really, therefore ensure that down the accuracy of measurement result with practical conditions.Following details is should be noted that in the placement process of electric current pole:
1) electric current pole need be uniformly distributed, and radical should be many as far as possible, and concrete radical can carry out contrast by measurement result when changing electric current pole radical at the scene and determine.Suggestion electric current pole radical is at least 8.
2) electric current pole and the enough distance of earthing device must be ensured, to make under heavy impulse current soil therebetween have nearly zero potential region.For finding the suitable layout distance of electric current pole, electric current pole radius of a circle can be changed, measurement result at different radii compared, Transient grounding resistance under adjacent three kinds of radiuses difference is within 10%, can choose the position that the maximum position of radius is electric current pole.Different from power current, the decay of dash current in soil is very fast, therefore advises the initial placement position of electric current pole and the border 5m of earthing device.
3) for increasing the recovering effect of dash current, the resistance at electric current pole place should be reduced as far as possible, comprise suitable increase electric current polar diameter and embedded depth, tamp electric current pole place soil to improve the measure such as the contact effect of itself and electric current pole, bold and vigorous (salt) water-wet electric current pole place soil.
B, the wiring of impulse current generator: draw a braiding copper cash as current feed from the high-pressure side of described impulse current generator, receive the measurement decanting point place of described earthing device; This mode of connection requires to possess moveable heavy current impact current feedback circuit, and impulse current generator should be positioned over the peripheral of the round path of electric current pole and keep certain distance with it.Impulse current generator should insulate with ground in placement, and available insulation column etc. carry out the isolation with ground.Impulse current generator body needs power supply, therefore needs the electric supply installations such as generator at the scene.For avoiding the superpotential that large impact electric current causes in actual measurement to work the mischief to electric power system (generator etc.), an isolating transformer must be connected in series between electric power system with impulse current generator.Isolating transformer and generator as far as possible away from electric current pole, and must should be placed in insulation against ground isolation, and carry out far-end zero potential ground connection.In current feed placement process, should be noted to possess certain insulation distance with objects such as ground, electric current pole or periphery weeds, cause flashover breakdown to avoid going between in actual measurement process between ground or other objects.
C, the measurement of decanting point voltage signal wiring: draw a unsettled voltage lead at the measurement decanting point place of described earthing device, be connected to described voltage divider and sentence the surge voltage signal obtaining decanting point place.For reducing electric current polar curve to the coupling of voltage divider cable measuring-signal, electric current pole bus bar can be disconnected at voltage divider place, as shown in Figure 1.For reducing current feed to the coupling of divider voltage lead signal, voltage lead and the angle of current feed in space should be not less than 90 °, as shown in Figure 2.
D, the measurement wiring of decanting point current signal: access described oscillograph at the collector ring place of described electric current pole by Luo-coil, be connected to described voltage divider at the described oscillographic other end by stub cable.With oscillograph-stub cable-Luo-coil that a charged pool is independently-powered in figure, measure as the current signal of an independent measuring unit to decanting point.Should be noted in wiring process, this independent measuring unit needs insulation against ground, and also at the dash current at the alternative decanting point place of current measurement at measurement collector ring place, electric current pole, as shown in Figure 1, the measurement result difference that both compare in amplitude and waveform is all little.
In addition, in measuring process, survey crew and measurement manipulation instrument all must carry out insulation against ground process, and appliance requires is independently-powered, and not allowing has any electrical connection with impact body and generator.
The distribution situation of lightning current in soil can be reflected more really by above-mentioned measuring method, can the Transient grounding resistance of Measurement accuracy grounding body.Measured result can check the design of grounding body whether to meet lightning protection requirement, and by surveying the impact of certain type grounding body, draw its coefficient of impact curve, only measure its power frequency earthing resistance in measuring at the scene in the future, in conjunction with existing coefficient of impact curve, just can calculate its Transient grounding resistance, contribute to the impact characteristics grasping grounding body, instruct and the design of checking engineering lightning protection, construction and operation, raising engineering overall security and reliability, have operability.
Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; although with reference to above-described embodiment to invention has been detailed description; those of ordinary skill in the field still can modify to the specific embodiment of the present invention or equivalent replacement; these do not depart from any amendment of spirit and scope of the invention or equivalent replacement, are all applying within the claims awaited the reply.
Claims (8)
1., based on an on-site measurement method for the Transient grounding resistance under heavy impulse current, measurement mechanism comprises earthing device, impulse current generator, Luo-coil, voltage divider, oscillograph and electric current pole;
It is characterized in that, described measuring method comprises the following steps:
A, the wiring of electric current pole: the round path being the center of circle with described earthing device is evenly arranged described electric current pole, to be extremely connected described electric current with braiding copper cash and to be connected to described impulse current generator body base;
B, the wiring of impulse current generator: draw braiding copper cash as current feed from the high-pressure side of described impulse current generator, and received the measurement decanting point place of described earthing device;
C, the measurement wiring of decanting point voltage signal: draw unsettled voltage lead at the measurement decanting point place of described earthing device, and be connected to the surge voltage signal that acquisition decanting point place sentenced by described voltage divider;
D, the measurement wiring of decanting point current signal: access described oscillograph at the collector ring place of described electric current pole by Luo-coil, described oscillographic other end stub cable is connected to described voltage divider.
2. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, described electric current pole radical is no less than 8.
3. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, the distance between the initial placement position of described electric current pole and the edge of described earthing device is 5m.
4. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, described impulse current generator is moveable impulse current generator.
5. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, described impulse current generator, described Luo-coil and described oscillograph all insulate with bottom surface.
6. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, described impulse current generator, described oscillograph are all independently-powered.
7. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, the bus bar of described electric current pole disconnects at described voltage divider place.
8. the on-site measurement method of Transient grounding resistance according to claim 1, is characterized in that, described voltage lead and current feed are not less than 90 ° at the angle in space.
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| CN105467248A (en) * | 2015-12-17 | 2016-04-06 | 清华大学 | Method for measuring and amending impact characteristics of grounding device |
| CN105606924A (en) * | 2015-12-17 | 2016-05-25 | 陕西省电力科学研究院 | Impact characteristic measurement correction method for grounding device |
| CN106199202A (en) * | 2015-05-05 | 2016-12-07 | 国家电网公司 | A kind of line steel tower grounded screen Transient grounding resistance measuring instrument |
| CN106597112A (en) * | 2016-10-31 | 2017-04-26 | 罗云峰 | Test equipment and test method thereof for testing impulse grounding resistance of transmission line pole type tower |
| CN106885946A (en) * | 2017-03-13 | 2017-06-23 | 贵州电网有限责任公司电力科学研究院 | A kind of impact grounding impedance measuring system and measuring method |
| CN107219423A (en) * | 2017-06-06 | 2017-09-29 | 中国电力科学研究院 | Lightning impulse response measurement system |
| CN109188090A (en) * | 2018-08-13 | 2019-01-11 | 西南交通大学 | The nonlinear test method of different humidity electric resistance of soil in vertical demixing soil |
| CN109470928A (en) * | 2018-06-26 | 2019-03-15 | 国网浙江省电力有限公司衢州供电公司 | The method of cloth pole measurement pole tower ground resistance in column foot |
| CN111722018A (en) * | 2020-06-17 | 2020-09-29 | 湖北宏源电力设计咨询有限公司 | Method for testing impulse grounding resistance of power transmission line tower |
| CN112415340A (en) * | 2020-10-27 | 2021-02-26 | 清华大学 | Device and method for observing three-dimensional discharge morphology of soil around grounding body |
| CN112505423A (en) * | 2020-11-30 | 2021-03-16 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of horizontal grounding electrode |
| CN112505424A (en) * | 2020-11-30 | 2021-03-16 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of vertical grounding electrode |
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| CN106199202A (en) * | 2015-05-05 | 2016-12-07 | 国家电网公司 | A kind of line steel tower grounded screen Transient grounding resistance measuring instrument |
| CN105606924A (en) * | 2015-12-17 | 2016-05-25 | 陕西省电力科学研究院 | Impact characteristic measurement correction method for grounding device |
| CN105467248A (en) * | 2015-12-17 | 2016-04-06 | 清华大学 | Method for measuring and amending impact characteristics of grounding device |
| CN106597112B (en) * | 2016-10-31 | 2019-04-02 | 杭州潇楠科技有限公司 | Shock ground resistance of transmission line tower test device and its method |
| CN106597112A (en) * | 2016-10-31 | 2017-04-26 | 罗云峰 | Test equipment and test method thereof for testing impulse grounding resistance of transmission line pole type tower |
| CN106885946A (en) * | 2017-03-13 | 2017-06-23 | 贵州电网有限责任公司电力科学研究院 | A kind of impact grounding impedance measuring system and measuring method |
| CN107219423A (en) * | 2017-06-06 | 2017-09-29 | 中国电力科学研究院 | Lightning impulse response measurement system |
| CN109470928A (en) * | 2018-06-26 | 2019-03-15 | 国网浙江省电力有限公司衢州供电公司 | The method of cloth pole measurement pole tower ground resistance in column foot |
| CN109470928B (en) * | 2018-06-26 | 2020-09-15 | 国网浙江省电力有限公司衢州供电公司 | Method for measuring tower grounding resistance by arranging poles in tower footing |
| CN109188090A (en) * | 2018-08-13 | 2019-01-11 | 西南交通大学 | The nonlinear test method of different humidity electric resistance of soil in vertical demixing soil |
| CN109188090B (en) * | 2018-08-13 | 2019-11-05 | 西南交通大学 | The nonlinear test method of different humidity electric resistance of soil in vertical demixing soil |
| CN111722018A (en) * | 2020-06-17 | 2020-09-29 | 湖北宏源电力设计咨询有限公司 | Method for testing impulse grounding resistance of power transmission line tower |
| CN112415340A (en) * | 2020-10-27 | 2021-02-26 | 清华大学 | Device and method for observing three-dimensional discharge morphology of soil around grounding body |
| CN112415340B (en) * | 2020-10-27 | 2021-12-21 | 清华大学 | Device and method for observing three-dimensional discharge morphology of soil around ground rod |
| CN112505423A (en) * | 2020-11-30 | 2021-03-16 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of horizontal grounding electrode |
| CN112505424A (en) * | 2020-11-30 | 2021-03-16 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of vertical grounding electrode |
| CN112505424B (en) * | 2020-11-30 | 2022-01-11 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of vertical grounding electrode |
| CN112505423B (en) * | 2020-11-30 | 2022-01-21 | 广东电网有限责任公司佛山供电局 | System and method for evaluating impact impedance distortion rate of horizontal grounding electrode |
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