CN104134984A - Neutral point virtual ground connection cabinet - Google Patents
Neutral point virtual ground connection cabinet Download PDFInfo
- Publication number
- CN104134984A CN104134984A CN201410367108.4A CN201410367108A CN104134984A CN 104134984 A CN104134984 A CN 104134984A CN 201410367108 A CN201410367108 A CN 201410367108A CN 104134984 A CN104134984 A CN 104134984A
- Authority
- CN
- China
- Prior art keywords
- cabinet
- voltage
- virtual ground
- isolator
- ground
- 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.)
- Pending
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a neutral point virtual ground connection cabinet, and relates to a ground connection cabinet. A disconnecting switch operation chamber is arranged below a secondary chamber. A simulation board, a door electromagnetic lock, a front door inspection window and a nameplate are arranged on a cabinet door of the disconnecting switch operation chamber. A disconnecting switch operation mechanism is arranged in the disconnecting switch operation chamber and connected with an auxiliary switch. A cabinet illuminating lamp is arranged below the disconnecting switch operation chamber. The disconnecting switch operation mechanism is further connected with a high-voltage disconnecting switch, a circuit connected with the high-voltage disconnecting switch is provided with a high-voltage sensor and a supporting insulator, the high-voltage disconnecting switch is further connected with high-voltage fuses, porcelain bottles are arranged between the high-voltage fuses, and the two high-voltage fuses are connected with a voltage transformer and a virtual ground connection transformer respectively. The neutral point virtual ground connection cabinet can provide system voltage signals for a metering device and a relay protection device, can replace a conventional PT cabinet and is high in performance cost ratio.
Description
Technical field
What the present invention relates to is a kind of ground connection cabinet, is specifically related to a kind of neutral point virtual ground cabinet.
Background technology
In 3-35KV medium voltage network, at present to have earth-free, resonance grounding be the earthing modes such as grounding through arc, low resistance grounding to neutral point in electric power system, and above-mentioned various earthing modes respectively have pluses and minuses.
For a long time in China, the electrical network of 3-35KV (containing 66KV) adopts the operational mode of isolated neutral mostly, isolated neutral system is due to investment, economical operation, power supply reliability is high to be widely adopted, but when there is single-phase arc grounding, can produce arc grounding overvoltage, very easily cause the damage of insulation in electric equipment or puncture accidents causedly, cause heavy losses.Expansion along with electrical network scale, the extensive use of cable, earthing capacitance current is increasing, in it when there is single-phase earthing, electric arc can not put out certainly, arc grounding overvoltage problem is more and more serious, in order to address the above problem, many electrical networks have adopted resonance grounding mode, resonance grounding is grounding through arc, the capacitance current of flow compensated through fault point makes it to be tending towards 0, arc light can not maintain burning and extinguish, fault point dielectric " air " is around supplemented can return to normal dielectric strength, the insulation of fault point no longer punctures, resonance grounding has very high power supply reliability and fail safe, but it is high to there is overvoltage multiple, precision tuning difficulty is large, route selection accuracy rate is low, assembly is many, complex structure, device faults itself rate is high, the shortcomings such as perspective long-term plan that are unfavorable for electrical network.The shortcoming of arc suppression coil maximum is can not bring into play extinguishing arc effect in cable line.
When the earth-free operation of neutral point of electric network, even if the capacitance current of system is little, also can make the current potential that perfects phase may be elevated to the degree that is enough to destroy its insulation level because of producing intermittent arc overvoltage when the single-phase earthing, even form phase fault.The electromagnetic energy in intermittent arc overvoltage if released after neutral point (or use grounding transformer and draw neutral point) serial connection one resistor of transformer; neutral point current potential reduces; the fault phase recovery voltage rate of climb also slows down; thereby reduce the possibility of arc reignition; suppressed the amplitude of power network overvoltage, and selectively ground protection is achieved.
Summary of the invention
For the deficiency existing in prior art, the present invention seeks to be to provide a kind of neutral point virtual ground cabinet, be specially adapted to generator outlet, transformer, and various superpotential absorption and the inhibition of the weak equipment of motor etc. self insulation.Can provide system voltage signal to measuring instrument and protective relaying device, can substitute conventional PT cabinet, cost performance is high simultaneously.
To achieve these goals, the present invention realizes by the following technical solutions: neutral point virtual ground cabinet, comprise three-phase voltage meter, Setup Controller, electrification display, comprehensive protection device, hinge, simulation board, auxiliary switch, door electromagnetic lock, Qianmen observation window, nameplate, isolator operating mechanism, cabinet intraoral illumination lamp, high pressure sensor, high voltage isolator, supporting insulator, cable built-in beam, earthing bar, secondary chamber, isolator operation chamber, porcelain vase, high-tension fuse, voltage transformer and virtual ground instrument transformer, before ground connection cabinet, upper lateral part is provided with secondary chamber, in secondary chamber, be provided with three-phase voltage meter, Setup Controller, electrification display, comprehensive protection device, ground connection all cabinet doors cashier's office in a shop are all fixed by hinge and cabinet, secondary chamber below is provided with isolator operation chamber, on the cabinet door of isolator operation chamber, be provided with simulation board, door electromagnetic lock, Qianmen observation window, nameplate, the indoor isolator operating mechanism that is provided with of isolator operation, isolator operating mechanism is connected with auxiliary switch, below, isolator operation chamber is provided with cabinet intraoral illumination lamp, isolator operating mechanism is also connected with high voltage isolator, on the circuit being connected with high voltage isolator, be also provided with high pressure sensor, supporting insulator, high voltage isolator is also connected with high-tension fuse, between high-tension fuse, be provided with porcelain vase, two high-tension fuses respectively with voltage transformer, virtual ground instrument transformer is connected, cable built-in beam, earthing bar is arranged on voltage transformer front side.
On described ground connection cabinet rear cabinet door, be provided with back door observation window.
The present invention has following beneficial effect:
1, restriction system resonance and overvoltage thereof, during system without considering parameter matching:
When electric power system designs, in system, the impedance of inductive element is easily calculated, but system capacitance to earth be difficult to calculate, this is mainly the equipment position of installing, the humidity of the path of line arrangement and height, height above sea level, climatic environment, air, environmental etc. all affect system capacitance over the ground.During design, calculating parameter coupling is reasonable, and on-the-spot actual parameter coupling is unreasonable.
The irrational system of parameter matching, when being subject to certain " excitation " (as operation, fault, thunderbolt etc.), system tend generation resonance, overvoltage multiple is high causing the accident very.
Virtual ground absorbs the energy of release " excitation " and resonance, eliminates its impact from source, prevents overvoltage, and therefore design is upper without taking into account system parameter matching problem.
2, refusal Ferroresonance Overvoltage Caused by PT overvoltage:
During voltage transformer generation resonance; virtual ground absorbs the resonant energy of releasing; from source, eliminate resonance overvoltage; three-phase voltage returns to normal voltage level very soon, has not only protected the insulation safety of system, has prevented the harm of resonance overvoltage to system insulation; guarantee that the characteristic of voltage transformer is forever in the range of linearity simultaneously; be high induction reactance, ensure that resonance can not develop, there is small resistor, high resistance ground.
3, realize transient fault (overhead transmission line, cable joint) extinguishing arc:
During ground connection arcing, virtual ground has absorbed the energy that ground connection excites, and significantly reduces ground connection oscillatory process on the one hand, reduces the harm of transient process to system; Virtual ground consumes the electric charge that arc light extinguishes direct-to-ground capacitance storage constantly fast on the other hand, reduce the speed that fault scratch start road voltage to earth recovers, be conducive to the recovery of arc road dielectric dielectric strength, Shi Hu road dielectric strength resume speed is greater than the resume speed of voltage to earth, virtual ground makes fault point voltage to earth approach phase voltage (while there is no virtual ground, fault point voltage to earth recovery maximum is not 2 times of phase voltages) simultaneously, therefore fault point can not puncture again, thereby realizes extinguishing arc.
4, the superpotential inhibition of cable line arc grounding:
When having virtual ground device, because absorbing the fault point of having released, virtual ground device punctures the energy exciting, significantly reduce transient process during arcing, make temporary overvoltage be less than 2.5 times; When arc light extinguishes, virtual ground consumes fast arc light and extinguishes the electric charge that direct-to-ground capacitance stores constantly, reduce the resume speed of voltage to earth, eliminated the impact of direct-to-ground capacitance storage electric charge, make arcing number of times reduce half, although for fault point again puncture voltage be less than the fault of line voltage can not extinguishing arc, but because virtual ground device absorbs the energy that fault point arcing blow-out excites of having released, can over-voltage suppression multiple in 2.5 times, arcing number of times reduces half, and the transient process while significantly reducing arcing.
Because overvoltage multiple is lower, can time delay excise or excise fast fault, meet the service requirement that various users are different, there is great flexibility.
5, the inhibition of Lightning Over-voltage:
Can hold greatly overvoltage protection device restriction atmospheric over-voltage and switching overvoltage
6, refusal wire-break resonance overvoltage:
While there is wire-break resonance overvoltage in electrical network, can generation systems neutral point displacement, the reversion of load transformer phase sequence, winding current sharply increase, iron core sends sound, wire sends the phenomenons such as corona sound.In severe case, can make insulation dodge and iron, Explosion of on Arrester, even damages power equipment.Virtual ground absorbs " excitation " energy of releasing and producing because of broken string, makes broken string cannot cause wire-break resonance at all.
7, prevent generator switching overvoltage:
Generator connecting in parallel with system can not be " same period " in complete meaning, and excision generator, must bring impact to system, especially mini system.Virtual ground absorbs the energy that this impact of releasing produces, and eliminates the impact of its generation.
8, suppress asymmetric harmonic wave, reduce the impact of asymmetric harmonic wave on transformer, motor, cable, capacitor, reduce transformer noise of motor, generate heat and have energy-saving effect.
Accompanying drawing explanation
Below in conjunction with the drawings and specific embodiments, describe the present invention in detail;
Fig. 1 is front view of the present invention;
Fig. 2 is end view of the present invention;
Fig. 3 is rearview of the present invention;
Fig. 4 is electrical schematic diagram of the present invention.
Embodiment
For technological means, creation characteristic that the present invention is realized, reach object and effect is easy to understand, below in conjunction with embodiment, further set forth the present invention.
With reference to Fig. 1-4, this embodiment is by the following technical solutions: neutral point virtual ground cabinet, comprise three-phase voltage meter 1, Setup Controller 2, electrification display 3, comprehensive protection device 4, hinge 5, simulation board 6, auxiliary switch 7, door electromagnetic lock 8, Qianmen observation window 9, nameplate 10, isolator operating mechanism 11, cabinet intraoral illumination lamp 12, high pressure sensor 13, high voltage isolator 14, supporting insulator 15, cable built-in beam 16, earthing bar 17, secondary chamber 18, isolator operation chamber 19, porcelain vase 20, high-tension fuse 21, voltage transformer 22 and virtual ground instrument transformer 23, before ground connection cabinet, upper lateral part is provided with secondary chamber 18, in secondary chamber 18, be provided with three-phase voltage meter 1, Setup Controller 2, electrification display 3, comprehensive protection device 4, ground connection all cabinet doors cashier's office in a shop are all fixed by hinge 5 and cabinet, secondary chamber 18 belows are provided with isolator operation chamber 19, on the cabinet door of isolator operation chamber 19, be provided with simulation board 6, door electromagnetic lock 8, Qianmen observation window 9, nameplate 10, in isolator operation chamber 19, be provided with isolator operating mechanism 11, isolator operating mechanism 11 is connected with auxiliary switch 7, 19 belows, isolator operation chamber are provided with cabinet intraoral illumination lamp 12, isolator operating mechanism 11 is also connected with high voltage isolator 14, on the circuit being connected with high voltage isolator 14, be also provided with high pressure sensor 13, supporting insulator 15, high voltage isolator 14 is also connected with high-tension fuse 21, between high-tension fuse 21, be provided with porcelain vase 20, two high-tension fuses 21 respectively with voltage transformer 22, virtual ground instrument transformer 23 is connected, cable built-in beam 16, earthing bar 17 is arranged on voltage transformer 22 front sides.
The core component of this embodiment device is to copy generator neutral point earthing method, implement special virtual ground instrument transformer, secondary side three-phase windings in series forms open delta, access high-power resistance, equivalent system neutral ground, earth-free to power frequency, to non-power-frequency earthing, realize system neutral " virtual " ground connection.Why being called " virtual " ground connection is because the capacity of virtual ground instrument transformer is little compared with the capacity of generator neutral point ground connection instrument transformer.
This embodiment adopts special virtual ground instrument transformer, the secondary side three-phase windings in series of virtual instrument transformer forms open delta, the power of its three phase winding is the size setting according to system direct-to-ground capacitance, open delta access resistance, equivalent system neutral ground, realizes system neutral virtual ground.
Optional function: virtual ground becomes a neutral point can be according to the PT primary connection mode of the overvoltage suppression cabinet of my company, ground connection after a neutral point is in parallel with a resonance eliminator by intelligent instant shut-in, intelligence instant shut-in PTK is when normal operation, PTK is in "on" position, a neutral-point solid ground of PT, when there is resonance, PTK opens, to connect and enter in the primary circuit of PT with a resonance eliminator of its parallel connection, earth impedance of PT is strengthened, PT primary current reduces, and reaches the effect of harmonic elimination; When PTK opens, the resonance eliminator harmonic elimination in the situation that of voltage transformer generation resonance.Resonance eliminator is by the characteristic of self intrinsic physical characteristic and equivalent neutral ground release fast electricity, the magnetic energy of resonance and single-phase earthing, when there is single-phase earthing, still can maintain operation a period of time, overvoltage level is reduced, there is very high power supply reliability and fail safe.
The advantage of the various neutral grounding modes of neutral point virtual ground cabinet set, active absorption is released and is produced various superpotential energy, from source, eliminates overvoltage, and refusal overvoltage, among rudiment, is given the guarantee of system safety operation maximum.Operational mode, can maintain operation during single-phase earthing flexibly, also can excise immediately fault, meets different service requirements; Very low overvoltage Limiting value, ensures to system insulation safety greatly.
The principle of science, novel method, nearly Utopian effect, the virtual ground mode of original creation, gathers the advantage of various neutral grounding modes, and active absorption is released and is produced various superpotential energy, from source, prevents overvoltage, and refusal overvoltage is among rudiment; Release electricity, the magnetic energy of resonance and single-phase earthing, realize extinguishing arc, and refusal system, PT ferro resonance are given the guarantee of system safety operation maximum.
The device of this embodiment can be integrated with voltage transformer cabinet, virtual ground cabinet, replaces voltage transformer cabinet.
More than show and described basic principle of the present invention and principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; that in above-described embodiment and specification, describes just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.The claimed scope of the present invention is defined by appending claims and equivalent thereof.
Claims (4)
1. neutral point virtual ground cabinet, it is characterized in that, comprise three-phase voltage meter (1), Setup Controller (2, electrification display (3), comprehensive protection device (4), hinge (5), simulation board (6), auxiliary switch (7), door electromagnetic lock (8), Qianmen observation window (9), nameplate (10), isolator operating mechanism (11), cabinet intraoral illumination lamp (12), high pressure sensor (13), high voltage isolator (14), supporting insulator (15), cable built-in beam (16), earthing bar (17), secondary chamber (18), isolator operation chamber (19), porcelain vase (20), high-tension fuse (21), voltage transformer (22) and virtual ground instrument transformer (23), before ground connection cabinet, upper lateral part is provided with secondary chamber (18), in secondary chamber (18), be provided with three-phase voltage meter (1), Setup Controller (2), electrification display (3), comprehensive protection device (4), ground connection all cabinet doors cashier's office in a shop are all fixed by hinge (5) and cabinet, secondary chamber (18) below is provided with isolator operation chamber (19), isolator operation chamber 19) on cabinet door, be provided with simulation board (6), door electromagnetic lock (8), Qianmen observation window (9), nameplate (10), in isolator operation chamber (19), be provided with isolator operating mechanism (11), isolator operating mechanism (11) is connected with auxiliary switch (7), below, isolator operation chamber (19) is provided with cabinet intraoral illumination lamp (12), isolator operating mechanism (11) is also connected with high voltage isolator (14), on the circuit being connected with high voltage isolator (14), be also provided with high pressure sensor (13), supporting insulator (15), high voltage isolator (14) is also connected with high-tension fuse (21), between high-tension fuse (21), be provided with porcelain vase (20), two high-tension fuses (21) respectively with voltage transformer (22), virtual ground instrument transformer (23) is connected, cable built-in beam (16), earthing bar (17) is arranged on voltage transformer (22) front side.
2. neutral point virtual ground cabinet according to claim 1, it is characterized in that, described virtual ground instrument transformer, secondary side three-phase windings in series forms open delta, access high-power resistance, equivalent system neutral ground, earth-free to power frequency, to non-power-frequency earthing, realize system neutral " virtual " ground connection.
3. neutral point virtual ground cabinet according to claim 1, it is characterized in that, the secondary side three-phase windings in series of described virtual ground instrument transformer forms open delta, the power of its three phase winding is the size setting according to system direct-to-ground capacitance, open delta access resistance, equivalent system neutral ground, realizes system neutral virtual ground.
4. neutral point virtual ground cabinet according to claim 1, is characterized in that, on described ground connection cabinet rear cabinet door, is provided with back door observation window (24).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410367108.4A CN104134984A (en) | 2014-07-30 | 2014-07-30 | Neutral point virtual ground connection cabinet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410367108.4A CN104134984A (en) | 2014-07-30 | 2014-07-30 | Neutral point virtual ground connection cabinet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104134984A true CN104134984A (en) | 2014-11-05 |
Family
ID=51807560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410367108.4A Pending CN104134984A (en) | 2014-07-30 | 2014-07-30 | Neutral point virtual ground connection cabinet |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104134984A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106329363A (en) * | 2015-06-15 | 2017-01-11 | 连际高新电气(上海)有限公司 | Novel environmental-protection intelligent switch cabinet |
| CN108512211A (en) * | 2018-05-25 | 2018-09-07 | 长江勘测规划设计研究有限责任公司 | Combine cabinet style impedance type gigantic generating units neutral earthing devices |
-
2014
- 2014-07-30 CN CN201410367108.4A patent/CN104134984A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106329363A (en) * | 2015-06-15 | 2017-01-11 | 连际高新电气(上海)有限公司 | Novel environmental-protection intelligent switch cabinet |
| CN108512211A (en) * | 2018-05-25 | 2018-09-07 | 长江勘测规划设计研究有限责任公司 | Combine cabinet style impedance type gigantic generating units neutral earthing devices |
| CN108512211B (en) * | 2018-05-25 | 2023-06-27 | 长江勘测规划设计研究有限责任公司 | Combined cabinet type impedance type giant generator set neutral point grounding device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Carsimamovic et al. | Very fast electromagnetic transients in air insulated substations and gas insulated substations due to disconnector switching | |
| CN104134984A (en) | Neutral point virtual ground connection cabinet | |
| CN201004553Y (en) | Arc over voltage limit for power transmission and distribution system and integrated device for small current grounding and line selection | |
| CN203932706U (en) | A kind of arc-extinguishing harmonic-eliminating cabinet | |
| CN104158163B (en) | VFTO protection device and method for transformer in GIS substation | |
| CN105356436B (en) | Multifunctional comprehensive circuit protection device | |
| CN104953578A (en) | System overvoltage suppression device | |
| CN203660531U (en) | Novel intelligent arc-extinguishing and over-voltage protection device | |
| CN205945048U (en) | Three -phase combined type over -voltage protector | |
| CN202696141U (en) | Arc-extinction resonance-elimination device | |
| CN201388042Y (en) | Central high-voltage switch equal-height cabinet | |
| CN203660532U (en) | Intelligent type arc-extinguishing overvoltage protector | |
| CN2638313Y (en) | Reactive compensation and arc-extinguishing resonance-extinguishing device | |
| CN204012702U (en) | A kind of arc-extinguishing harmonic-eliminating cabinet with virtual ground device | |
| CN204030580U (en) | A kind of overvoltage inhibiting apparatus with small current line selection | |
| Chi et al. | Comparison and analysis on Very Fast Transient Overvoltage based on 550kV GIS and 800kV GIS | |
| CN201387999Y (en) | Central high-low cabinet type intelligent arc extinction, harmonic elimination and route selection device | |
| CN202872357U (en) | Optimized comprehensive protection device of power grid | |
| CN203135434U (en) | Neutral point virtual grounding device | |
| CN106129989A (en) | A kind of three phase combined over-voltage protector | |
| CN203326598U (en) | Arc-extinguishing, resonance-eliminating and all-overvoltage inhibiting cabinet | |
| CN201388009Y (en) | Central isolated handcart type arc extinction, harmonic elimination and route selection device | |
| CN209642058U (en) | A kind of overvoltage suppression cabinet | |
| CN102709899A (en) | Intelligent arc extinction and resonance extinction overvoltage protection integral optimization device | |
| CN202616767U (en) | Intelligent comprehensive arc-extinction resonance-elimination overvoltage protection optimizing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141105 |