CN202513569U - Transformer neutral point overvoltage protector - Google Patents
Transformer neutral point overvoltage protector Download PDFInfo
- Publication number
- CN202513569U CN202513569U CN2012201716547U CN201220171654U CN202513569U CN 202513569 U CN202513569 U CN 202513569U CN 2012201716547 U CN2012201716547 U CN 2012201716547U CN 201220171654 U CN201220171654 U CN 201220171654U CN 202513569 U CN202513569 U CN 202513569U
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- China
- Prior art keywords
- transformer
- neutral point
- monitor
- discharging
- gapless metal
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- 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.)
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- 230000007935 neutral effect Effects 0.000 title claims abstract description 38
- 230000001012 protector Effects 0.000 title abstract 6
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 22
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 22
- 238000007599 discharging Methods 0.000 claims abstract description 17
- 239000012212 insulator Substances 0.000 claims description 13
- 238000009413 insulation Methods 0.000 abstract description 16
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 abstract 3
- 238000002955 isolation Methods 0.000 abstract 2
- 238000000034 method Methods 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 3
- 230000002950 deficient Effects 0.000 description 2
- 230000003534 oscillatory effect Effects 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 206010001541 Akinesia Diseases 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
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- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model relates to a transformer neutral point overvoltage protector, which comprises a power transformer, a grounding isolation switch, a gapless metal oxide lightning arrester, and an insulation pedestal. The gapless metal oxide lightening arrester is arranged on the insulation pedestal and is connected to the ground via a monitor or a discharging register, wherein the monitor or the discharging register is connected to the gapless metal oxide lightening arrester; a current transformer is arranged on the outboard of the insulation pedestal, and the current transformer and a discharging gap position are in series connection and are than connected to the ground; simultaneously, the grounding isolation switch, a combination in which the gapless metal oxide lightening arrester is in series connection with the monitor or the discharging register position, and a combination in which the current transformer is in series connection with the discharging gap position, are in parallel connection between a transformer neutral point of the power transformer and the ground. The transformer neutral point overvoltage protector has the advantages that insulation cooperation among protection levels of the protector, gap discharging characteristics of the protector, and insulation levels of the transformer neutral point is reasonable, that thermal runaway is not caused in the neutral point protection, that it is avoided that misoperations cause accidents, and that the service life of the protector is long.
Description
Technical field
The utility model relates to the over-voltage protection technique of electric power system, relates in particular to a kind of transformer neutral point overvoltage protection about insulation coordination between protection of arrester level, gap discharge and the transformer neutral point insulation level three.
Background technology
At present; In 110kV and above electric power system; Its transformer mostly moves with the neutral-point solid ground mode, but rectifies the needs that dispose and control direction of tide for limiting short-circuit current, relaying protection, often will the part transformer neutral point be moved with earth-free mode; So neutral point will be protected, in order to avoid overvoltage is damaged the insulation of transformer neutral point and caused the accident.Protected mode commonly used is to be main with gapless metal-oxide lighting arrester (abbreviation MOA) and discharging gap Combined Protection; Be equipped with the complete sets of equipment of earthing isolator, current transformer again; Wherein: earthing isolator is used to change the neutral point operational mode; Zero-sequence current when current transformer discharges in order to the interrecord gap (IGP); The insulation of transformer neutral point mainly protection equipment is MOA and discharging gap, and MOA bears the defencive function of lightning overvoltage and switching overvoltage, and discharging gap is born the defencive function of the temporary overvoltage of longer duration.But in the prior art; There are very big defective in the protection level of the flash-over characteristic in gap and MOA and the cooperation between the transformer neutral point insulation level three, the reasonable matching problem of discharge voltage (power-frequency sparkover voltage and impulse sparkover voltage) of the indeterminate gap of more specifically saying so (no matter being single gap or control gap) and the rated voltage of MOA (specific to the power-frequency voltage tolerance time characteristic of MOA); Then the discharge voltage in its gap (especially power-frequency sparkover voltage) has got lowly sometimes, and this has not only wasted the insulation of transformer neutral point, and makes the gap be prone to misoperation to cause the accident; Sometimes obtain too highly, the gap can't be played a protective role, thereby cause MOA to hold temporary overvoltage that can't stand longer duration and cause thermal runaway.Therefore, to above aspect, need reasonably improve prior art.
The utility model content
To above defective, the transformer neutral point overvoltage protection that the utility model provides a kind of and makes insulation coordination more rationally, can not cause thermal runaway, can avoid the misoperation accident, service life of equipment is long is to solve many deficiencies of prior art.
For realizing above-mentioned purpose, the utility model adopts following technical scheme:
A kind of transformer neutral point overvoltage protection; Comprise power transformer, earthing isolator, gapless metal-oxide lighting arrester, insulator foot; Said gapless metal-oxide lighting arrester is installed on the insulator foot and passes through the outside monitor that connects or discharge register ground connection, ground connection after said insulator foot arranged outside one current transformer and this current transformer and discharging gap position are connected in series; Simultaneously; Said earthing isolator, gapless metal-oxide lighting arrester and monitor or the combination of discharge register serial connection, current transformer and the serial connection combination of discharging gap position; This three part is connected in parallel, and is connected between the transformer neutral point and ground of power transformer.In addition, said monitor or discharge register upper end connect gapless metal-oxide lighting arrester and are in parallel installed with on the ground connection base with insulator foot.
For above characteristic; Gapless metal-oxide lighting arrester (MOA) is the high energy permittivity of zinc; At this important technological parameters and defencive function that relates to insulation coordination be: rated voltage Ur, nominal discharge current residual voltage Ures and power-frequency voltage tolerance time characteristic, said rated voltage Ur is 0.57 times (Ur ≡ 0.57Um) of the ceiling voltage Um of system; Said nominal discharge current residual voltage Ures is 0.8 times (Ures=0.8Us=Us/1.25) less than transformer neutral point insulation level (lightning impulse withstand voltage Us); Said power-frequency voltage tolerance time characteristic (high energy valve block) is: 1.3Ur, 0.1s, 1.15Ur, 10s, 1.0Ur, 20min; Or 1.25Ur, 0.1s, 1.2Ur, 1s, 1.15Ur, 10s, 1.0Ur, 20min; Simultaneously, the flash-over characteristic in said gap is: power-frequency sparkover voltage U
The worker, lightning impulse discharge voltage U
Dash, said power-frequency sparkover voltage U
The workerThe principle that cooperates with the power-frequency voltage tolerance time characteristic of MOA is: (the former breaks down and t≤0.5s when being started by backup protection, and then value is: 1.05Ur≤U to consider earth fault duration≤10s (DL/T804 power industry standard regulation) in the solidly earthed neutral system, quick relaying protection and backup protection
The worker＜1.15Ur; Said lightning impulse discharge voltage U
DashThe principle that cooperates with the MOA characteristic is: its value is not more than MOA nominal discharge current residual voltage (U
Dash≯ Ures).
The beneficial effect of the described transformer neutral point overvoltage protection of the utility model is:
(1) helps giving full play to the excellent nonlinear characteristic of gapless metal-oxide lighting arrester, realize that the insulation coordination between its protection level, gap discharge characteristic and the transformer neutral point insulation level three is reasonable;
(2) can bring into play lightning arrester high energy valve block and suppress the ability of temporary overvoltage and absorb the ability of overvoltage energy that (7kj～13kj)/kV rationally cooperates with the gap power-frequency sparkover voltage, in neutral point protection, can not cause thermal runaway;
(3) help making gap power-frequency sparkover voltage characteristic value to cooperate appropriately with the power-frequency voltage tolerance time characteristic of lightning arrester; Gap discharge voltage receives the control of higher limit and lower limit; Dispersed little, discharge stability, in the temporary overvoltage scope that lightning arrester can bear; The gap can not moved, and then can not cause the accident that misoperation causes;
(4) duration that combines relaying protection in the solidly earthed neutral system (protection and backup protection fast) measure, temporary overvoltage to reach the oscillatory process before the steady-state value is to be that 0.2s and lightning arrester power-frequency voltage tolerance time characteristic select to confirm gap power-frequency sparkover voltage value scope about 10 cycles; Rational in infrastructure, economical and practical, service life of equipment is long, thereby given full play to lightning arrester and the gap Combined Protection advantage of function separately.
Description of drawings
According to accompanying drawing the utility model is done further explain below.
Fig. 1 is that the said transformer neutral point overvoltage protection of the utility model embodiment connects sketch map.
Among the figure:
1, power transformer; 2, transformer neutral point; 3, earthing isolator; 4, gapless metal-oxide lighting arrester; 5, monitor or discharge register; 6, insulator foot; 7, current transformer; 8, discharging gap position.
Embodiment
As shown in Figure 1; The described transformer neutral point overvoltage protection of the utility model embodiment; Comprise power transformer 1, earthing isolator 3, gapless metal-oxide lighting arrester 4, insulator foot 6; Said gapless metal-oxide lighting arrester 4 is installed on the insulator foot 6 and passes through the outside monitor that connects or discharge register 5 ground connection; Monitor wherein or discharge register 5 upper ends connect gapless metal-oxide lighting arrester 4 and are in parallel installed with on the ground connection base with insulator foot 6, ground connection after said insulator foot 6 arranged outside, one current transformer 7 and this current transformer 7 are connected in series with discharging gap position 8; Simultaneously; Said earthing isolator 3, gapless metal-oxide lighting arrester 4 and monitor or the 5 serial connection combinations of discharge register, current transformer 7 and the 8 serial connection combinations of discharging gap position; This three part is connected in parallel, and is connected between the transformer neutral point 2 and ground of power transformer 1; Earthing isolator 3 wherein is used to change the operational mode of neutral point; Monitor or discharge register 5 are used to monitor the leakage current and the action frequency of gapless metal-oxide lighting arrester 4, the zero-sequence current of system when discharge in current transformer 7 interrecord gap (IGP)s wherein.
Above embodiment is more preferably embodiment a kind of of the utility model; According to the principle that the flash-over characteristic of the protective value of the determined gapless metal-oxide lighting arrester 4 of above scheme and discharging gap position 8 cooperates, getting gap power-frequency sparkover voltage value is the 1.05Ur≤U of MOA rated voltage
The worker＜1.15Ur; Then MOA can tolerance under the temporary overvoltage of 1.15Ur time＞10s; Single-line to ground fault is the common form of fault; Single-phase grounding fault causes isolated neutral transformer neutral point temporary overvoltage, and possibly occur because of broken string or the temporary overvoltage of switch tripping when causing open-phase operation.Neutral point voltage is being tending towards before the steady-state value individual oscillatory process being arranged, about 10 cycles of duration of oscillation, power industry standard regulation neutral ground trouble duration≤10s.Like this, the Frequency Transient Overvoltage that causes in lightning overvoltage, switching overvoltage and various fault (its amplitude less than 1.05Ur time) is born protective effect by MOA, and the gap akinesia guarantees power supply safety; And when the temporary overvoltage amplitude reaches or surpass 1.15Ur, the gap precision maneuver, MOA thermal runaway accident is exempted in the operation of transformer neutral point transient earthing, and the lasting extension of fault has been avoided in and then system's tripping operation.
Above embodiment is more preferably embodiment a kind of of the utility model, and common variation that those skilled in the art carry out in present technique scheme scope and replacement should be included in the protection range of the utility model.
Claims (2)
1. transformer neutral point overvoltage protection; Comprise power transformer (1), earthing isolator (3), gapless metal-oxide lighting arrester (4), insulator foot (6); It is characterized in that: said gapless metal-oxide lighting arrester (4) is installed in monitor or discharge register (5) ground connection that outside connection was gone up and passed through to insulator foot (6), ground connection after said insulator foot (6) arranged outside one current transformer (7) and this current transformer (7) are connected in series with discharging gap position (8); Simultaneously; Said earthing isolator (3), gapless metal-oxide lighting arrester (4) and monitor or the combination of discharge register (5) serial connection, current transformer (7) and the combination of discharging gap position (8) serial connection; This three part is connected in parallel, and is connected between the transformer neutral point (2) and ground of power transformer (1).
2. transformer neutral point overvoltage protection according to claim 1 is characterized in that: said monitor or discharge register (5) upper end connect gapless metal-oxide lighting arrester (4) and are in parallel installed with on the ground connection base with insulator foot (6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201716547U CN202513569U (en) | 2012-04-20 | 2012-04-20 | Transformer neutral point overvoltage protector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012201716547U CN202513569U (en) | 2012-04-20 | 2012-04-20 | Transformer neutral point overvoltage protector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202513569U true CN202513569U (en) | 2012-10-31 |
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ID=47066026
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012201716547U Expired - Fee Related CN202513569U (en) | 2012-04-20 | 2012-04-20 | Transformer neutral point overvoltage protector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202513569U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103138237A (en) * | 2013-02-26 | 2013-06-05 | 深圳供电局有限公司 | Method and device for protecting gap action of transformer neutral point |
| CN104767191B (en) * | 2015-04-09 | 2019-04-05 | 国家电网公司 | A kind of inverter earthed system |
| CN110492462A (en) * | 2019-08-30 | 2019-11-22 | 国网陕西省电力公司电力科学研究院 | A kind of surge arrester with parallel gaps for the protection of 110kV transformer neutral point |
-
2012
- 2012-04-20 CN CN2012201716547U patent/CN202513569U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103138237A (en) * | 2013-02-26 | 2013-06-05 | 深圳供电局有限公司 | Method and device for protecting gap action of transformer neutral point |
| CN103138237B (en) * | 2013-02-26 | 2015-05-20 | 深圳供电局有限公司 | Method and device for protecting gap action of transformer neutral point |
| CN104767191B (en) * | 2015-04-09 | 2019-04-05 | 国家电网公司 | A kind of inverter earthed system |
| CN110492462A (en) * | 2019-08-30 | 2019-11-22 | 国网陕西省电力公司电力科学研究院 | A kind of surge arrester with parallel gaps for the protection of 110kV transformer neutral point |
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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 |
Granted publication date: 20121031 Termination date: 20150420 |
|
| EXPY | Termination of patent right or utility model |