CN101478119B - Earthing process for transforming plant protecting device shielding chamber - Google Patents

Earthing process for transforming plant protecting device shielding chamber Download PDF

Info

Publication number
CN101478119B
CN101478119B CN2009100606561A CN200910060656A CN101478119B CN 101478119 B CN101478119 B CN 101478119B CN 2009100606561 A CN2009100606561 A CN 2009100606561A CN 200910060656 A CN200910060656 A CN 200910060656A CN 101478119 B CN101478119 B CN 101478119B
Authority
CN
China
Prior art keywords
earthing
ground
ground connection
protection cell
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN2009100606561A
Other languages
Chinese (zh)
Other versions
CN101478119A (en
Inventor
邬雄
万保权
张广洲
张小武
王勤
蒋虹
张业茂
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Electric Power Research Institute
Original Assignee
State Grid Electric Power Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Electric Power Research Institute filed Critical State Grid Electric Power Research Institute
Priority to CN2009100606561A priority Critical patent/CN101478119B/en
Publication of CN101478119A publication Critical patent/CN101478119A/en
Application granted granted Critical
Publication of CN101478119B publication Critical patent/CN101478119B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The invention relates to a grounding method for a shielding chamber of protective equipment in a transformer substation. The method comprises the following steps: firstly, the aim to ground a protective chamber is analyzed; after the aim is known, the influences of the different grounding modes on reduction of electromagnetic disturbance are compared; and the reasonable grounding modes and the realization methods are determined through tests, investigations, and accumulation of operating experience. The grounding method is very accurate, and can provide basis and reference for designing the grounding of the protective chamber of secondary units in high-voltage transformer substations in the future.

Description

A kind of earthing process for transforming plant protecting device shielding chamber
Technical field
The invention belongs to high voltage power transmission and transforming engineering electromagnetic compatibility field, is a kind of earthing process for transforming plant protecting device shielding chamber specifically.
Background technology
China's power construction develop rapidly; It is the electric power networks of trunk skeleton that the present whole nation has formed 500kV electric pressure transmission line; Three Gorges Projects highly visible are to see the project of transmitting and converting electricity of class of track off with the 500kV electric pressure promptly, and the need for electricity of China's sustainable development of socio-economy has been satisfied in the operation operation of Three Gorges Projects greatly.
Project of transmitting and converting electricity comprises transmission of electricity and two parts of power transformation, and transformer station promptly carries out power transformation task wherein.Because the charged high-tension apparatus of transformer station is many, dense degree is big, and along with the raising of electric pressure, electromagnetic environment is more complicated.500kV transformer substation voltage grade is high, and the complexity of the electromagnetic environment in its switch place, severity make people be installed in the problem statement into questions such as fail safe, functional reliability of on-the-spot secondary device to these.The electromagnetic environment of trouble free service is provided for the secondary device of giving on-the-spot operation; Adopting the protection cell of shielding to solve protection and transfer the contradiction of The Application of Technology and forceful electric power magnetic environment as jamproof measure, is domestic 500kV transformer substation construction and the existing a kind of mode of operation.
Protection cell on earth mat is ground connection how, is one of major issue of protection cell design and construction.Because the ground connection shortage to the protection cell, goed deep into systematic research, brought certain difficulty for the design that reduces electromagnetic disturbance, and irrational earthing method can make the protection cell lose due protection effect, bring hidden danger for the safe and stable operation of electric power system.
Summary of the invention
The present invention is from the purpose of protection cell ground connection; Analyzed the influence of different earthing modes; According to test and operating experience a kind of safe and reliable earthing process for transforming plant protecting device shielding chamber is provided, for the design of the protection cell ground connection of voltage levels substation secondary device from now on provides foundation and reference.
To achieve these goals; The method that the present invention adopted is: the purpose of at first analyzing protection cell ground connection; Clear and definite after the purpose of ground connection; Relatively different earthing mode is given and is lowered the influence that electromagnetic disturbance brings, and confirms rational earthing mode and realization means through the accumulation of test, investigation and operating experience.
Its concrete steps are:
First step: the purpose of analyzing protection cell ground connection;
Second step: analyze of the influence of different earthing methods to electromagnetic disturbance:
Ground connection is divided into single-point grounding usually, kinds such as multipoint earthing and mixing ground connection;
Single-point grounding: the ground wire of all circuit is received the same point of common ground, further can be divided into series connection single-point grounding and parallelly connected single-point grounding;
Multipoint earthing: the ground wire of all circuit is received the difference of common ground, and general circuit is ground connection nearby;
Mix ground connection: in earth system, use inductance, electric capacity to connect, utilize inductance, capacitor element that the characteristic of different impedance is arranged, make earth system have different ground structures in different frequencies under different frequency;
Third step: confirm protection cell earthing method:
Confirming of the mode of protection cell ground connection mainly should be from reducing the angle of electromagnetic disturbance.
Through the design and the practical operating experiences of transforming plant protecting cell, the present invention has high accuracy and reliability, for the design of the protection cell ground connection of voltage levels substation secondary device from now on provides foundation and reference.
Description of drawings
Fig. 1 is a cable grounding mode sketch map of the present invention.
Embodiment
Below in conjunction with accompanying drawing and embodiment the present invention is made further detailed description, but this embodiment should not be construed as limitation of the present invention.
Detailed step of the present invention is:
First step: the purpose of analyzing protection cell ground connection;
Be embedded with special ground network in the transformer station, and the design of ground network should be satisfied the requirement of various conditions:
A. lower earth resistance;
B. limit step voltage and touch voltage;
C. reduce the harassing and wrecking of high and low frequency common mode;
D. can bear the big electric current of short circuit.
Protection cell on earth mat is ground connection how, is one of major issue of protection cell design and construction.Obviously reduce the purpose that the harassing and wrecking of high and low frequency common mode are protection cell ground connection, and the source of common mode harassing and wrecking, the one, the earth potential that thunderbolt or short trouble cause raises, and the 2nd, institute connects cable and conducts and come.
Second step: different earthing methods are to the influence of electromagnetic disturbance
Ground connection is divided into single-point grounding usually, kinds such as multipoint earthing and mixing ground connection.
Single-point grounding: the ground wire of all circuit is received the same point of common ground, further can be divided into series connection single-point grounding and parallelly connected single-point grounding.
Multipoint earthing: the ground wire of all circuit is received the difference of common ground, and general circuit is ground connection nearby.
Mix ground connection: in earth system, use inductance, electric capacity to connect, utilize inductance, capacitor element that the characteristic of different impedance is arranged, make earth system have different ground structures in different frequencies under different frequency.
1) single-point grounding
Single-point grounding has two kinds of forms, and a kind of is the series connection single-point grounding, and another kind is parallelly connected single-point grounding.In the series connection single-point grounding, between many circuit common impedance is arranged, therefore very serious by the interference of common impedance coupling generation each other.
Though this earthing mode has very big problem, be modal in the reality, because it is very simple.Ways of addressing this issue is parallelly connected single-point grounding.But parallelly connected single-point grounding needs more lead, can adopt series, parallel to mix ground connection in the practice.
Series connection single-point ground structure is owing to simply receiving designer's favor, but the common impedance coupled interference problem that it brings often lets people's headache again.Parallel connection single-point grounding structure can thoroughly be eliminated the influence between the circuit, but ground connection is complicated, and lead long meeting causing impedance ground is bigger.
A compromise method: circuit is divided into groups according to characteristic, and the circuit that is difficult for each other taking place to disturb is placed on same group, and the circuit that takes place easily each other to disturb is placed on different groups.Adopt the series connection single-point grounding in each group, obtain the simplest ground configurations, on the same group ground connection is not adopted parallelly connected single-point grounding, avoids disturbing each other.
The key of this method: the shared one section ground wire of the circuit that very big circuit of power difference or level are differed greatly.
2) multipoint earthing
In order to reduce the ground wire inductance, in high-frequency circuit and digital circuit, often use multipoint earthing.In the multipoint earthing system, each circuit is received on the low-impedance ground plane nearby.The earth connection of circuit will be lacked as far as possible, to reduce inductance.In the very high system of operating frequency, usually earth connection will be controlled in several millimeters the scope.
As previously mentioned, be easy to generate the ground loop problem during multipoint earthing.In the occasion of low frequency, can address this problem through single-point grounding.But when high frequency, can only solve through reducing grounding wire impedance (reducing the ground loop).Because skin effect, electric current only flow at conductive surface, the thickness that therefore increases conductor can not reduce the resistance of conductor.At the silver-plated resistance that can reduce conductor of conductive surface.
When the common 1MHz of operating frequency is following, can use single-point grounding; When 10MHz is above, can use multipoint earthing, in the time of between 1MHz and 10MHz, if the longest earth connection is no more than 1/20 of wavelength, can use single-point grounding, otherwise use multipoint earthing.
3) mix ground connection
Mix grounding system and present different ground structures in different frequencies;
Third step: confirm protection cell earthing method
Confirming of the mode of protection cell ground connection mainly should be from reducing the angle of electromagnetic disturbance.
Table 1 has been listed operation unloaded bus caused harassing and wrecking result of calculation, can be found out by data in the table, take cable sheath in the control room or protection cell input end grounding better.
Disturbance voltage (calculating) during table 1 operation (closing) aircraft carrier line
According to correlative study, parallel earthing conductor should be in the cell external ground that enters the mouth, and does not introduce in the cell.If the safety regulation permission, parallel earthing conductor CT, PT secondary side ground connection, can not reduce disturbance voltage (Fig. 1) the terminal box ground connection of CT, PT.
The problem that the transient state earth potential that causes about thunder and lightning rises, according to result of calculation, when near the member the protection cell suffered the 30kA thunderbolt, maximum potential difference was about hundreds of 1kV of lying prostrate (being lower than 1kV) in the protection cell.The thunderbolt that it is pointed out that 30kA belongs to more intense thunder-strike phenomenon in statistics, the probability of appearance is less, so calculate the tight partially situation of being considered of genus.Considering the existing immunity to interference level of secondary device, such current potential is not enough to cause the unusual of equipment work.
Equipment is numerous in the transforming plant protecting cell, and operating frequency is not high, and frequency is 50HZz during operate as normal, and adopting multipoint earthing obviously is irrational with mixing ground connection, adopts single-point grounding to be advisable.Be excellent with parallelly connected single-point grounding in the single-point grounding, but since in the protection cell each equipment room have certain distance, if all adopt parallelly connected single-point grounding, the ground wire of some equipment can be very long, the compromise single-point grounding mode that should adopt preceding text to introduce.
In addition, the great amount of calculation through to the thunderbolt grounding net of transformer substation obtains following Main Conclusions:
The first, the thunderbolt grounding net of transformer substation will cause the transient state earth potential liter that produces uneven distribution in the protection cell, and it will produce electromagnetic interference to these secondary devices through the grounding system of secondary devices such as protection and control in the protection cell.
The second, should single pavement ground network in the protection cell, this ground network preferably adopts four angle point connected modes to be connected with grounding net of transformer substation, maximum transient state potential difference minimum in the protection cell when guaranteeing to be struck by lightning grounding net of transformer substation.Because difficult realization during four angle point connected mode practice of construction, the single-point connection is connected with four angle points to be compared, and maximum transient state potential difference differs and is not too big in the protection cell, according to practical operating experiences, adopts single-point to connect satisfying the demand.
The 3rd, under the identical connected mode of protection cell ground network, copper ground network makes in the protection cell maximum transient state potential difference little than steel ground network, but effect and not obvious.Reduce to protect the size of mesh opening of cell ground network more effective for maximum transient state potential difference in the reduction protection cell than using copper ground network.
The 4th, distance protection cell in lightning rod position is near more, and the maximum transient state potential difference that in the protection cell, produces during the thunderbolt lightning rod is also big more.Therefore, the position of lightning rod should be as far as possible away from the protection cell.
According to above research and practical operating experiences, should adopt installing ground connection copper bar (being preferably formed as the closed-loop path) in the protection cell to the ground connection of protection cell, copper bar is carried out single-point with power transformation station owner earth mat and reliably is connected.
The content of not doing in this specification to describe in detail belongs to this area professional and technical personnel's known prior art.

Claims (5)

1. earthing process for transforming plant protecting device shielding chamber; The method that is adopted is: at first analyze the purpose of protection cell ground connection, clear and definite after the purpose of ground connection, relatively different earthing mode is given and is lowered the influence that electromagnetic disturbance brings; Confirm earthing mode and realization means, its concrete steps are:
First step: the purpose of analyzing protection cell ground connection:
In transformer station, be embedded with special ground network, and the requirement that meets the following conditions of the design of ground network:
A. lower earth resistance;
B. limit step voltage and touch voltage;
C. reduce the harassing and wrecking of high and low frequency common mode;
D. can bear the big electric current of short circuit;
Then reducing high and low frequency common mode harassing and wrecking is purposes of protection cell ground connection, and the source of common mode harassing and wrecking, the one, and the earth potential that thunderbolt or short trouble cause raises, and the 2nd, institute connects cable and conducts and come;
Second step: analyze of the influence of different earthing methods to electromagnetic disturbance:
Ground connection is divided into single-point grounding, kinds such as multipoint earthing and mixing ground connection;
Single-point grounding: the ground wire of all circuit is received the same point of common ground, further can be divided into series connection single-point grounding and parallelly connected single-point grounding;
Multipoint earthing: the ground wire of all circuit is received the difference of common ground, and general circuit is ground connection nearby;
Mix ground connection: in earth system, use inductance, electric capacity to connect, utilize inductance, capacitor element that the characteristic of different impedance is arranged, make earth system have different ground structures in different frequencies under different frequency;
Third step: confirm protection cell earthing method:
Confirming of the mode of protection cell ground connection from reducing the angle of electromagnetic disturbance.
2. earthing process for transforming plant protecting device shielding chamber as claimed in claim 1 is characterized in that: single-point grounding has two kinds of forms in second step, and a kind of is the series connection single-point grounding; Another kind is parallelly connected single-point grounding; Its concrete grammar is: circuit is divided into groups according to characteristic, and the circuit that is difficult for each other taking place to disturb is placed on same group, and the circuit that takes place easily each other to disturb is placed on different groups; Adopt the series connection single-point grounding in each group; On the same group ground connection is not adopted parallelly connected single-point grounding, avoids disturbing each other the shared one section ground wire of the circuit that very big circuit of power difference or level are differed greatly.
3. according to claim 1 or claim 2 earthing process for transforming plant protecting device shielding chamber, it is characterized in that: operating frequency is used single-point grounding in second step when 1MHz is following; When 10MHz is above, use multipoint earthing, in the time of between 1MHz and 10MHz,, use single-point grounding, otherwise use multipoint earthing if the longest earth connection is no more than 1/20 of wavelength.
4. earthing process for transforming plant protecting device shielding chamber as claimed in claim 1 is characterized in that: the protection cell takes cable sheath in the control room or the earthing method of protection cell input end grounding.
5. earthing process for transforming plant protecting device shielding chamber as claimed in claim 1 is characterized in that: the ground connection of protection cell is adopted installing ground connection copper bar in the protection cell, and copper bar is carried out the method that single-point is connected with power transformation station owner earth mat.
CN2009100606561A 2009-01-24 2009-01-24 Earthing process for transforming plant protecting device shielding chamber Active CN101478119B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2009100606561A CN101478119B (en) 2009-01-24 2009-01-24 Earthing process for transforming plant protecting device shielding chamber

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2009100606561A CN101478119B (en) 2009-01-24 2009-01-24 Earthing process for transforming plant protecting device shielding chamber

Publications (2)

Publication Number Publication Date
CN101478119A CN101478119A (en) 2009-07-08
CN101478119B true CN101478119B (en) 2012-05-09

Family

ID=40838767

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2009100606561A Active CN101478119B (en) 2009-01-24 2009-01-24 Earthing process for transforming plant protecting device shielding chamber

Country Status (1)

Country Link
CN (1) CN101478119B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102832553A (en) * 2012-08-20 2012-12-19 深圳供电局有限公司 Transformer substation earthing system
CN103220899B (en) * 2013-04-01 2015-11-25 中联重科股份有限公司 A kind of screen type variable grounding control device, system, method and engineering machinery
CN105811333B (en) * 2014-12-29 2018-08-14 华北电力大学 A kind of cable routing box for intelligent substation electronic device
CN105160172B (en) * 2015-08-31 2018-09-11 国家电网公司 A kind of method of determining GIS intelligent substations component ports electromagnetic disturbance
CN108174594A (en) * 2018-01-10 2018-06-15 信息产业电子第十设计研究院科技工程股份有限公司 It is a kind of based on high voltage, heavy-current discharge under the conditions of solve electromagnetic shielding and ionization radiation protection electrical system
CN109188152B (en) * 2018-10-15 2021-02-12 青岛四方庞巴迪铁路运输设备有限公司 Method for detecting common-mode disturbance of grounding circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN85105582A (en) * 1985-06-27 1986-12-24 三菱电机株式会社 The earthed switch of strip resistance device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN85105582A (en) * 1985-06-27 1986-12-24 三菱电机株式会社 The earthed switch of strip resistance device

Also Published As

Publication number Publication date
CN101478119A (en) 2009-07-08

Similar Documents

Publication Publication Date Title
CN101478119B (en) Earthing process for transforming plant protecting device shielding chamber
CN104569608B (en) A kind of Transient grounding resistance on-site measurement method based under heavy impulse current
CN204649859U (en) A kind of transmission line of electricity over-voltage measurement analogue test platform
CN103810323A (en) Method for assessing transformer substation communication device grounding body potential rising
Vita et al. The impact of distributed generation to the lightning protection of modern distribution lines
CN103823103A (en) Overvoltage on-line monitoring device and method
CN103913661A (en) Method for estimating influences on telecommunication cable E1 wire by electromagnetic disturbance
Miri et al. Transient electromagnetic phenomena in the secondary circuits of voltage and current transformers in GIS (measurements and calculations)
CN205539343U (en) Integration probe is put in office based on electric capacity divides platen press VFTO measuring transducer
Zhang et al. Mechanism of±800 kV HVDC converter abnormal block fault caused by lightning transient
Li et al. Lightning transient characteristics of cable power collection system in wind power plants
CN105067889A (en) Method of measuring secondary cable transfer impedance caused by ground net impact current
Said et al. Corona lightning overvoltage analysis for a 500 kV hybrid line
CN204597473U (en) The indoor 7 grades of lightning-protection systems of a kind of network center machine room
CN104360193B (en) Electromagnetic disturbance simulation test platform of transformer substation secondary system
Shangzun et al. Study on electromagnetic radiation of ultra-high voltage power transmission line
Lehtonen et al. Ground potential rise and lightning overvoltages in control systems of large power-plants under high soil resistivity
Caetano et al. A conductor arrangement that overcomes the effective length issue in transmission line grounding: full-scale measurements
CN203660078U (en) Lightning-protection structure of building
CN104820148A (en) Over-voltage measurement and simulation test platform of power transmission line
CN202563012U (en) Large-scale power station grounding net impedance parameter measuring device
Gu et al. Analysis of the characteristics and impact of lightning on smart substations
Li et al. Sheath Induced Over-Voltage Characteristic in 220 kV Power Cable Under Lightning Over-Voltage
Denker et al. Evaluation of Lightning Current Distribution on Macro Base Station Telecom Sites
Na et al. Research on the Characteristics of TEV when Disconnector Operating in UHV GIS

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
GR01 Patent grant
C14 Grant of patent or utility model