LVQB(T)-35/66/110/220
Adopting advanced SF6 gas insulation technology and optimized internal structural design, the LVQB(T) series features excellent insulation performance, uniform electric field distribution and extremely low dielectric loss. Filled with high-purity SF6 insulating gas, the transformer maintains stable insulation performance under variable temperature and pressure conditions, effectively avoiding partial discharge and ensuring long-term safe operation.
The product is equipped with high-quality low-loss magnetic cores and precision winding technology, realizing accurate current transformation ratio and ultra-low measurement error. It can effectively resist strong electromagnetic interference in complex power grid environments, guaranteeing high measurement accuracy and reliable protection response for power system operation.
With an integrated fully sealed metal shell structure, the LVQB(T) series prevents gas leakage, moisture and dust intrusion. The high-strength anti-corrosion and anti-fouling porcelain sleeve adapts to various harsh outdoor environments, including high altitude, low temperature, coastal salt fog and industrial pollution areas, supporting stable all-weather outdoor operation.
Optimized with scientific structural layout, this SF6 gas insulated current transformer features compact structure, strong overload capacity and low operating noise. It requires minimal daily maintenance, greatly reducing operational and maintenance costs for medium and high voltage power grid construction and renovation projects.
As core and reliable power equipment for 35kV-220kV power engineering, the LVQB(T) series outdoor SF6 gas insulated current transformers deliver superior operational stability and measurement precision. We provide global customers with factory direct supply, complete certification documents and professional one-stop after-sales service.
Product Details
LVQB(T)-35/66/110/220
type SF6 gas insulated current transformer
□Introduction
□LVQB(T)-35/66/110/220 type current transformeris a kind of SF6 gas insulated independent current transformer with inverted structure researched and developed by our factory on the basis of similar products at home and abroad,it adopts SF6 gas of high electric-strength as the insulating medium,when comparing with oil-immersed transformer,this product has advantages of good insulating performance,long service life,short production cycle,simplified processes,oil free,maintenance free,safe and reliable running,it meets the modern power grid's high reliability requirements to the power transmission and transformation equipment.
□ Characteristic of structure
□The product adopts inverted structure,is composed of shell,explosion-proof sheet,machine body,bushing,base,density relay and other parts,there is shielding part inside the product that is used to improve the electric field,the secondary lead wire is connected in an airtight junction box, the shell can be divided into tee type and bell-jar type two types.
□Main insulation part adopts structure of coaxial columned uniform electric field.Primary guide rod and secondary shielding part form the coaxial columned uniform electric field mutually.Adopt primary series and parallel connection mode to change the current ratio,also could adopt primary parallel connection, all transformation ratios are got from the secondary tap.
□U pper part of the shell is equipped with explosion-proof sheet.Internal insulation of SF6gas insulated transformer boasts of high reliability,generally, it is impossible to have internal insulating fault arc,but considering internal arc may be caused by unpredictable accidental factors,we equip it with a explosion-proof sheet as a kind of safety measures.
□ External insulating bushing:products up to and including 220kV adopt high-strength porcelain bushing or HTV rubber composite hollow insulating bushing,it is able to withstand rated pressure of 1.6MPa(breaking pressure >4.0MPa).
□Base of the product is equipped with SF6 gas density relay,rated pressure is0.4MPa,when the internal pressure of product is 0.35MPa,density relay will give an alarm;when the pressure is 0.30MPa,density relay will give another alarm.SF6 density relay has automatic temperature compensation function,the indicated pressure value at-40℃~+60℃equals to the pressure value(density)at room temperature(20℃).Density relay is equipped with special nonreturn self-sealing valve,when the pressure gauge is removed,the valve will close automatically.
□ Sealing performance is the most important problem of SF6electrical apparatuses,the product adopts mature sealing structure design and strict position
-limit sealing,employs high quality sealing materials,meanwhile,it adopts sealant and waterproof adhesive to ensure long-term sealing performance, guarantee annual leakage rate of product is≤0.5%,make sure long-term safety running of product.
□Primary connection terminal adopts integral die-casting forming,has high mechanical strength.
□ Technical data
(1)Altitude:not exceed 2000m (the ones exceed 2000m shall be designed separately)
(2)Ambient temperature:-40℃~+50℃, daily mean temperature not exceeds 30℃
(3)Max monthly mean relative humidity:90%
(4)10min max average wind velocity:35m/s
5)Max ice coating thickness:10mm
(6)Class of pollution:Ⅲ、IV Class
2.Max voltage of equipment:40.5/72.5/126/252kV
3. Rated frequency:50H z
4. Rated primary current:300～4000A
5.Rated secondary current:1Aor5A
6.Secondary combination:0.2、0.2S、0.5、0.5S、5P、TPY、TPS
Class combination at random
7. Rated output:0.2 class、0.2S class、0.5 class、0.5S class、 5P class:20～60VA TPY class: 10~20Ω
8.Accuracy limit factor:20～40
9.Instrument security factor: ≤5
10.A ccuracy limit condition of class TPY:
a.primary time constant Tp=100ms or 60ms
b.short-circuit current direct component 100%(i.e.full migration)
c.specified working cycle:C-0.1 s-0-0.5S(or0.4S)-C-0.1s-0 (guarantee all accuracy class times are 0.4s)
d.symmetrical short-circuit current multiple:10、15、20
11. Rated insulating level:current transformer of 35kV; Current transformer of 66kV:72.5/140/325kV
Current transformer of 110kV:126/200/480kV Current transformer of 220kV:252/395/950kV
12.Short-time thermal current:50-63kA、3S
13.Rated peak withstand current:125-160kA(peak)
14.Withstand voltage level under zero gauge pressure:1.3 times
of max working voltage of equipment
15.Partial discharge level:1.2 times of max working voltage of equipment ≤5pC
16.Annual gas leakage rate:≤0.5%
17. Water content of SF6 gas:≤150×10-6(V/V)
18.Radio interference level:1.1 times of max working voltage of equipment,radio interference voltage≤500μV
19.Specific creepage distance of external insulation:25mm/kV or 31mm/kV
20.Static bearing load of primary terminal:2000N~6000N
21.Max total mass of product:current transformer of 35kV:450kg (thereinto mass of SF6 gas is 4kg)
Current transformer of 66kV:500kg (thereinto mass of SF6gas is 5kg)
Current transformer of 110kV:600kg(thereinto mass of SF6gas is 7kg)
Current transformer of 220kV:1400kg(thereinto mass of SF6 gas is23kg)
□Outline dimension
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