CN204230882U - A kind of 10 kv grid neutral earthing devices - Google Patents
A kind of 10 kv grid neutral earthing devices Download PDFInfo
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- CN204230882U CN204230882U CN201420709497.XU CN201420709497U CN204230882U CN 204230882 U CN204230882 U CN 204230882U CN 201420709497 U CN201420709497 U CN 201420709497U CN 204230882 U CN204230882 U CN 204230882U
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- nonlinear resistance
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- neutral
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- 230000007935 neutral effect Effects 0.000 title claims abstract description 39
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 229960001296 zinc oxide Drugs 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- 230000008033 biological extinction Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
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Abstract
The utility model relates to a kind of 10 kv grid neutral earthing devices, belongs to neutral point in electric power system grounding technology field.10kV neutral point of electric network is connected with the first nonlinear resistance through isolating switch, and the two ends of the first nonlinear resistance are connected in parallel on fast current-limiting fuse, and the circuit after parallel connection is connected with the second nonlinear resistance; The branch circuit parallel connection connected with by multiple special fuse and multiple nonlinear resistance in the two ends of the second nonlinear resistance, the circuit after parallel connection is connected with the earth through zero sequence current mutual inductor; The signal entering signal controller that zero sequence current mutual inductor gathers, for controlling the action of isolating switch and fast current-limiting fuse.The utility model earthing device; there is very high power supply reliability and excellent overvoltage protection performance; possess the advantage of low-impedance earthed system system, also there is the advantage that capacity is large, cost is low, structure is simple, floor space is little simultaneously, make the scope of application of earthing device wider.
Description
Technical field
The utility model relates to a kind of 10 kv grid neutral earthing devices, particularly relates to the neutral earthing devices based on nonlinear resistance and fuse, belongs to neutral point in electric power system grounding technology field.
Background technology
Existing 10 kilovolts of electric power system is joined a net neutral grounding mode and is mainly contained isolated neutral, neutral by arc extinction coil grounding and Neutral Point Through Low Resistance.
These three kinds of modes respectively have advantage, but also there is obvious shortcoming.Isolated neutral mode is simple, but the scope of application is less.When capacitance current is larger, very easily generation arc light is crossed and is pressed, and therefore isolated neutral mode can only be applicable to the region that in electric power system, capacitance current is very little.Grounding through arc mode is the capacitance current gone by outputting inductance electric current in bucking-out system, thus reduce earth fault electric current, prolongation system holds the time of operating with failure, and lowers the probability that arc light overvoltage occurs, and can reduce the probability that single-phase fault develops into phase-to phase fault simultaneously.But its shortcoming is power frequency overvoltage long-term existence in the ground connection time, and after offset current, be difficult to accurately select faulty line.Simultaneously in the region that capacitance current is larger, need the arc suppression coil capacity of configuration very large, greatly improve project cost and floor space.The principle of low resistance grounding mode produces obvious current signal by the small resistor of neutral point, can timely isolated fault circuit by protective device.But due to transient fault and non-momentary fault cannot be distinguished, and all implement tripping operation, cause line tripping rate too high, have impact on system power supply reliability.
Summary of the invention
The purpose of this utility model proposes a kind of 10 kv grid neutral earthing devices, existing neutral earthing devices is improved, and be core parts with zinc oxide varistor valve, collocation is selected through science, connect, make the voltage-current characteristic of each road energy Zinc-oxide piezoresistor identical, then pass through parallel connection, thus form a jumbo nonlinear resistance earthing device, to improve the power supply reliability of electrical network.
The 10 kv grid neutral earthing devices that the utility model proposes, comprise isolating switch, the first nonlinear resistance, fast current-limiting fuse, multiple special fuse, the second nonlinear resistance, multiple 3rd nonlinear resistance, zero sequence current mutual inductor and signal controller, 10kV neutral point of electric network is connected with the first nonlinear resistance through isolating switch, the two ends of the first nonlinear resistance are connected in parallel on fast current-limiting fuse, and the circuit after parallel connection is connected with the second nonlinear resistance; The branch circuit parallel connection connected with by multiple special fuse and multiple nonlinear resistance in the two ends of the second nonlinear resistance, the circuit after parallel connection is connected with the earth through zero sequence current mutual inductor; The signal entering signal controller that zero sequence current mutual inductor gathers, for controlling the action of isolating switch and fast current-limiting fuse.
The 10 kv grid neutral earthing devices that the utility model proposes, compare with device with original earthing mode, its advantage is: this neutral earthing devices has very excellent non-linear, it is high-impedance state when system is normally run, very little by electric current wherein, be equivalent to open-circuit condition, at this moment system is non-effective earthing mode, therefore has very high power supply reliability.No matter which kind of reason, when system generation resonance, when ground connection or other reasons produce overvoltage, capital produces higher voltage at the neutral point of system, now zero sequence current mutual inductor senses voltage, signal controller sends signal, special fuse is fused, nonlinear resistance drops into immediately, by overvoltage Limiting in the scope of setting, at this moment nonlinear resistance is small resistor state, be equivalent to low-impedance earthed system, and electric current changes within a large range, and the voltage at neutral earthing devices two ends remains unchanged substantially, therefore this neutral earthing devices has excellent overvoltage protection performance, therefore the advantage of low-impedance earthed system system has been possessed again.Centre-point earth device of the present utility model, also has the advantage that capacity is large, cost is low, structure is simple, floor space is little, makes the scope of application of earthing device wider.
Accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of 10kV neutral point of electric network earthing device.
In Fig. 1,1 is 10kV neutral point of electric network, and 2 is isolating switches, and 3 is first nonlinear resistances, and 4 is fast current-limiting fuses, and 5 is special fuses, and 6 is zero sequence current mutual inductors, and 7 is signal controllers, and 8 is second nonlinear resistances, and 9 is the 3rd nonlinear resistances.
Embodiment
The 10 kv grid neutral earthing devices that the utility model proposes, this earthing device accesses this neutral earthing devices on 10kV neutral point of electric network 1.The circuit theory diagrams of each neutral earthing devices as shown in Figure 1, comprise isolating switch 2, first nonlinear resistance 3, fast current-limiting fuse 4, multiple special fuse 5, second nonlinear resistance 8, multiple 3rd nonlinear resistance 9, zero sequence current mutual inductor 6 and signal controller 7,10kV neutral point of electric network 1 is connected with the first nonlinear resistance 3 through isolating switch 2, the two ends of the first nonlinear resistance 3 are connected in parallel on fast current-limiting fuse 4, and the circuit after parallel connection is connected with the second nonlinear resistance 8; The branch circuit parallel connection connected with by multiple special fuse 5 and multiple nonlinear resistance 9 in the two ends of the second nonlinear resistance 8, the circuit after parallel connection is connected with the earth through zero sequence current mutual inductor 6; The signal entering signal controller 7 that zero sequence current mutual inductor 6 gathers, for controlling the action of isolating switch 2 and fast current-limiting fuse 4.
Below in conjunction with accompanying drawing, introduce operation principle and the course of work of the centre-point earth device that the utility model proposes in detail:
Novel neutral point earthing device has very excellent non-linear, and when 10 kilovolts of electric power systems normally run, Novel neutral point earthing device is failure to actuate, and entirety presents in high-impedance state, is equivalent to open-circuit condition.The neutral point of at this moment 10 kilovolts of electric power systems is non-effective earthing mode, has very high power supply reliability.
When 10 kilovolts of electric power system generation resonance, ground connection or other reasons produce overvoltage, all higher voltage can will be produced at neutral point 1 place of 10 kilovolts of electric power systems.After zero sequence current mutual inductor 6 senses voltage, signal controller 7 sends signal and is fused by fast current-limiting fuse 4, and the first nonlinear resistance 3 drops into immediately, by overvoltage Limiting in the scope of setting.At this moment first, second, and third nonlinear resistance is small resistor state; be equivalent to low-impedance earthed system; and can be changed within a large range by the electric current of Novel neutral point earthing device; and the voltage at Novel neutral point earthing device two ends remains unchanged substantially, there is excellent overvoltage protection performance.
In an embodiment of the utility model earthing device, the parameter of the first nonlinear resistance 3, second nonlinear resistance 8 and multiple 3rd nonlinear resistance 9 is that direct current 10mA reference voltage gets 8.3 ~ 9.2 kilovolts, leakage current is 50 microamperes, 300 amperes are impacted lower residual voltage is 12 kilovolts, and 0.3 second impact energy is 5750 kilojoules.The fusing time of fast current-limiting fuse 4 is less than 6 milliseconds.
Claims (1)
1. a kv grid neutral earthing devices, it is characterized in that this earthing device comprises isolating switch, the first nonlinear resistance, fast current-limiting fuse, multiple special fuse, the second nonlinear resistance, multiple 3rd nonlinear resistance, zero sequence current mutual inductor and signal controller, 10kV neutral point of electric network is connected with the first nonlinear resistance through isolating switch, the two ends of the first nonlinear resistance are connected in parallel on fast current-limiting fuse, and the circuit after parallel connection is connected with the second nonlinear resistance; The branch circuit parallel connection connected with by multiple special fuse and multiple nonlinear resistance in the two ends of the second nonlinear resistance, the circuit after parallel connection is connected with the earth through zero sequence current mutual inductor; The signal entering signal controller that zero sequence current mutual inductor gathers, for controlling the action of isolating switch and fast current-limiting fuse.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420709497.XU CN204230882U (en) | 2014-11-21 | 2014-11-21 | A kind of 10 kv grid neutral earthing devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420709497.XU CN204230882U (en) | 2014-11-21 | 2014-11-21 | A kind of 10 kv grid neutral earthing devices |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204230882U true CN204230882U (en) | 2015-03-25 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420709497.XU Expired - Fee Related CN204230882U (en) | 2014-11-21 | 2014-11-21 | A kind of 10 kv grid neutral earthing devices |
Country Status (1)
| Country | Link |
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| CN (1) | CN204230882U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104410058A (en) * | 2014-11-21 | 2015-03-11 | 国家电网公司 | 10000 volt power grid neutral point grounding device |
| CN113820633A (en) * | 2021-09-15 | 2021-12-21 | 上海舒盈科技股份有限公司 | Fuse specification determination method, system, terminal and medium for fusing type overvoltage protection device |
-
2014
- 2014-11-21 CN CN201420709497.XU patent/CN204230882U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104410058A (en) * | 2014-11-21 | 2015-03-11 | 国家电网公司 | 10000 volt power grid neutral point grounding device |
| CN113820633A (en) * | 2021-09-15 | 2021-12-21 | 上海舒盈科技股份有限公司 | Fuse specification determination method, system, terminal and medium for fusing type overvoltage protection device |
| CN113820633B (en) * | 2021-09-15 | 2024-02-27 | 上海舒盈科技股份有限公司 | Fuse specification determination method, system, terminal and medium for fusing overvoltage protection device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150325 Termination date: 20161121 |