CN101378192A - Resistance-grounded system - Google Patents
Resistance-grounded system Download PDFInfo
- Publication number
- CN101378192A CN101378192A CNA2007100926448A CN200710092644A CN101378192A CN 101378192 A CN101378192 A CN 101378192A CN A2007100926448 A CNA2007100926448 A CN A2007100926448A CN 200710092644 A CN200710092644 A CN 200710092644A CN 101378192 A CN101378192 A CN 101378192A
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- neutral
- thyristor
- transformer
- resistance
- neutral point
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Abstract
The invention belongs to the technical field of electricity, discloses a resistance grounding system, and particularly relates to an automatic control resistance grounding system. One end of a neutral-point isolating switch is connected with one end of a neutral-point current transformer, the other end of the neutral-point isolating switch is connected with one end of a power transformer, the other end of the neutral-point current transformer is connected with one end of a thyristor which can be opened and closed, the other end of the thyristor which can be closed is connected with a neutral-point grounding resistance, the other end of the power transformer is connected with a voltage transformer, and two triangle ends of a secondary opening of the voltage transformer is connected with the relay for controlling the opening and closing of the neutral-point thyristor. The automatic control resistance grounding system improves the reliability of medium-voltage power distribution, prevents the occurrence of cable fires, and can be widely applied in 3 to 35kV industrial enterprises and city network power distribution systems.
Description
Technical field
The invention belongs to the electroporation field, disclose a kind of resistance grounded system, particularly a kind of automatic controlling resistance grounding system.
Background technology
Current national economy fast development is for satisfy industrial and agricultural production and people's lives need for electricity, the development that China's power generating equipment and city net power supply and distribution facility are also advanced by leaps and bounds thereupon.Wherein, 3-35kV industrial enterprise and city net be for the distribution neutral grounding mode, be related to medium voltage network for the distribution safe power supply one of important and key subject.At present, in based on the worker enterprise of cable and city net, press power supply-distribution system, adopting the resistance neutral grounding mode is trend of the times, advanced industrially developed country medium-pressure electricity supplies such as America and Europe, Japan are all based on cable, adopt neutral grounding mode to become the common recognition of various countries, and in large-scale reconstruction and extension projects such as Baosteel, Taiyuan Iron and Steel Co., obtain the practice confirmation.Press power supply-distribution system to adopt cable line or overhead wire and cable hybrid power supply circuit substantially among 3-35kV, seldom adopt independent overhead transmission line.This is adopted the neutral resistor grounding system is to prevent grounding surge, particularly the most effective safeguard procedures of batch (-type) arc grounding.It is safeguard procedures fundamentally, we can say and effects a permanent cure.And other all is the passive measure that prevents for the zinc oxide arrester that prevents the superpotential various modes of connection, rc absorber, arc suppression coil etc.
The weak point of neutral resistor grounding system is: before earth fault is eliminated, earth fault current potential is on every side raise, as not adopting timely tripping operation measure, will cause the insulation breakdown of equipment, the people's of crisis simultaneously life security; To batch (-type) ground connection and metal ground connection,, can not very be judged accurately sometimes though get its earth current value of 20～30%; Because make, actual use can cause the three-phase imbalance problem, generally can reach about 10～20%, therefore 10～20% unbalanced so-called residual voltage is arranged on neutral resistor.Particularly the interference of 3 times or 3 multiple subharmonic voltage more can not be ignored, this interference can not be ignored the interference of modernized numerical control system, owing to the three-phase imbalance residual voltage, the electric energy loss that the zero-sequence current of generation produces on earth resistance also can not be ignored simultaneously.
Summary of the invention
The object of the present invention is to provide novel resistance grounded system,, put forward high pressure and supply the distribution reliability and prevent that cable fire from taking place to overcome the weak point of neutral resistor grounding system.The present invention can be widely used in 3-35kV industrial enterprise and the city net power supply-distribution system.
Purpose of the present invention realizes in the following manner:
Neutral point isolating switch one end links to each other with an end of neutral point current instrument transformer, the neutral point isolating switch other end links to each other with power transformer one end, the other end of neutral point current instrument transformer links to each other with can opening with an end of turn-off thyristor, the other end of turn-off thyristor links to each other with neutral resistance, the power transformer other end links to each other with voltage transformer, and voltage transformer secondary open-delta two ends cut-off control relay with the neutral point thyristor and link to each other.
Description of drawings
Accompanying drawing is a resistance grounded system schematic diagram of the present invention.
Among the figure, part 1 is the neutral point isolating switch, and part 2 is neutral point current instrument transformers, and part 3 is can open and turn-off thyristor, and part 4 is neutral resistances, and part 5 is power transformers, and part 6 is that the neutral point thyristor cut-offs control relay, and part 7 is voltage transformers.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described further:
Neutral point isolating switch 1 one ends link to each other with an end of neutral point current instrument transformer 2, neutral point isolating switch 1 other end links to each other with power transformer 5 one ends, the other end of neutral point current instrument transformer 2 links to each other with can opening with an end of turn-off thyristor 3, the other end of turn-off thyristor 3 links to each other with neutral resistance 4, power transformer 5 other ends link to each other with voltage transformer 7, and voltage transformer 7 secondary open-deltas two ends cut-off control relay 6 with the neutral point thyristor and link to each other.
Power transformer 5 can change 110～35kV into 10～3kV, and the neutral point thyristor cut-offs control relay 6 band adjustable resistances, and voltage transformer is measured the uneven residual voltage u of open-delta
0
The present invention is in neutral resistance back polyphone thyristor automatic switching control system; Automatic setting thyristor conducting threshold voltage promptly guarantees residual voltage (10～20%) the not conducting of reverse-blocking tetrode thyristor that three-phase imbalance produces owing to normal operation the time, prevents and overcome the weak point of neutral resistor grounding system; When single-phase earthing takes place when; be the paranormal unbalanced residual voltage of neutral point place voltage meeting, in case surpass set point, the instantaneous conducting of gate-controlled switch; resistance is inserted the earth apace, finish the various protections of resistance earth neutral system and prevent superpotential function.
The present invention can put forward high pressure and supply the distribution reliability and prevent that cable fire from taking place, and is widely used in 3-35kV industrial enterprise and the city net power supply-distribution system.
Claims (2)
1, a kind of resistance grounded system, by the neutral point isolating switch, neutral resistance and power transformer are formed, it is characterized in that: neutral point isolating switch one end links to each other with an end of neutral point current instrument transformer, the neutral point isolating switch other end links to each other with power transformer one end, the other end of neutral point current instrument transformer links to each other with can opening with an end of turn-off thyristor, the other end of turn-off thyristor links to each other with neutral resistance, the power transformer other end links to each other with voltage transformer, and voltage transformer secondary open-delta two ends cut-off control relay with the neutral point thyristor and link to each other.
2, resistance grounded system according to claim 1 is characterized in that: the neutral point thyristor cut-offs control relay band adjustable resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100926448A CN101378192A (en) | 2007-08-31 | 2007-08-31 | Resistance-grounded system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100926448A CN101378192A (en) | 2007-08-31 | 2007-08-31 | Resistance-grounded system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101378192A true CN101378192A (en) | 2009-03-04 |
Family
ID=40421584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007100926448A Pending CN101378192A (en) | 2007-08-31 | 2007-08-31 | Resistance-grounded system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101378192A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102842900A (en) * | 2012-08-17 | 2012-12-26 | 河北省首钢迁安钢铁有限责任公司 | Power supply circuit of crane |
| CN103560500A (en) * | 2013-11-05 | 2014-02-05 | 国家电网公司 | Energy-saving selecting method for grounding resistor of transformer substation grounding transformer |
| CN109449912A (en) * | 2018-11-26 | 2019-03-08 | 中国电力科学研究院有限公司 | Neutral earthing devices and its control method |
| CN112332403A (en) * | 2020-09-22 | 2021-02-05 | 山东电力工程咨询院有限公司 | Superconducting air-core transformer and system for changing 35kV neutral point grounding mode of power grid |
-
2007
- 2007-08-31 CN CNA2007100926448A patent/CN101378192A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102842900A (en) * | 2012-08-17 | 2012-12-26 | 河北省首钢迁安钢铁有限责任公司 | Power supply circuit of crane |
| CN103560500A (en) * | 2013-11-05 | 2014-02-05 | 国家电网公司 | Energy-saving selecting method for grounding resistor of transformer substation grounding transformer |
| CN103560500B (en) * | 2013-11-05 | 2016-08-17 | 国家电网公司 | The energy-conservation choosing method of substation grounding transformer grounding resistance |
| CN109449912A (en) * | 2018-11-26 | 2019-03-08 | 中国电力科学研究院有限公司 | Neutral earthing devices and its control method |
| CN109449912B (en) * | 2018-11-26 | 2022-03-04 | 中国电力科学研究院有限公司 | Neutral point grounding device and control method thereof |
| CN112332403A (en) * | 2020-09-22 | 2021-02-05 | 山东电力工程咨询院有限公司 | Superconducting air-core transformer and system for changing 35kV neutral point grounding mode of power grid |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Open date: 20090304 |