AGU / LVQB / LB current transformers 110–765 kV (inverted oil-filled, SF6 gas-insulated, U-shaped winding)
AGU, LVQB and LB are current transformers rated 126–800 kV for 110–765 kV networks. The range covers inverted oil-filled units, SF6 gas-insulated units and oil-filled units with a U-shaped winding for measurement, metering and relay protection.
- Oil-filled inverted type
- AGU-800 (800 kV, LI 2100 kV), AGU-550 (550 kV), AGU-252 (252 kV)
- SF6 gas-insulated
- LVQB-220 (252 kV), LVQB-110 (126 kV)
- U-shaped primary winding
- LB9-220 (252 kV), LB6-110 (126 kV)
- 800 kV insulation
- LI 2100 / AC 975 / SI 1550 kV, creepage distance 20,000 mm
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
These current transformers for 110–765 kV networks are built in three designs: inverted oil-filled, SF6 gas-insulated and oil-filled with a U-shaped primary winding. They pass current signals to measurement, metering, relay protection and control circuits and isolate the secondary circuits from high voltage. By purpose they are equivalents of TFZM, TOGF, TRG and TVG 110–750 kV units. The units operate at 110–750 kV substations and outdoor switchgear, on transmission lines and at power plants.
In the oil-filled AGU-800, AGU-550 and AGU-252 the secondary windings sit at the top in a shielded aluminium housing, and their leads run through an aluminium tube to the terminal box at the base. The primary conductor passes through the centre of the secondary winding, and the main capacitor-type paper-oil insulation is wound over the housing and the tube. The unit is compact, withstands high dynamic and thermal short-circuit currents and cools well because the primary winding is in air.
The AGU-800 has a highest operating voltage of 800 kV, test voltages of LI 2100, AC 975 and SI 1550 kV, and a creepage distance of 20,000 mm. It was the first in China to pass a seismic test at intensity 8 on a 7 m steel support with composite insulators, as well as a heat transfer test. In 2014 the transformer was accepted by India's national grid, 32 units were energised there at the same time on 19 March 2015, and according to the manufacturer they have been in service for 9 years. Three AGU-800 units stand in the DC filters of the Butuo station of the 800 kV Baihetan–Jiangsu transmission link, where they operate at high altitude and withstand a DC test voltage of 150 kV. The AGU-550 (550 kV, LI 1675 kV) and AGU-252 (252 kV, LI 1050 kV) are widely used in power systems.
The SF6 gas-insulated LVQB-220 (252 kV) and LVQB-110 (126 kV) have no fire or explosion hazard, no dielectric losses and no insulation ageing. They have low leakage reactance and high dynamic and thermal withstand.
The LB9-220 (252 kV) and LB6-110 (126 kV) have a U-shaped primary winding with capacitor-type paper-oil insulation and equalising screens, the inner one at high potential and the outer one earthed. The secondary windings are located at the bottom. The insulation is wound automatically, the centre of gravity is low and seismic performance is high. For the 252 kV class the insulation is LI 1050 and AC 460 kV, the chopped wave is 1175 kV and the creepage distance is 7812 mm. The manufacturer states a service life of over 40 years owing to low losses and partial discharges.
Technical specifications
| Oil-filled inverted type | AGU-800 (800 kV, LI 2100 kV), AGU-550 (550 kV), AGU-252 (252 kV) |
|---|---|
| SF6 gas-insulated | LVQB-220 (252 kV), LVQB-110 (126 kV) |
| U-shaped primary winding | LB9-220 (252 kV), LB6-110 (126 kV) |
| 800 kV insulation | LI 2100 / AC 975 / SI 1550 kV, creepage distance 20,000 mm |
| 252 kV insulation | LI 1050 / AC 460 kV, chopped wave 1175 kV, creepage distance 7812 mm |
| Seismic withstand | intensity 8 (AGU-800 on a 7 m support, composite insulators) |
| Service life | over 40 years (stated) |
Replacement for
ТФЗМ-110Б, ТФЗМ-220Б, ТФУМ-330, ТФРМ-500, ТФРМ-750 (oil-filled), ТОГФ-110, ТРГ-220, ТРГ-500 (SF6 gas-insulated)
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
AGU / LVQB / LB current transformers 110–765 kV (inverted oil-filled, SF6 gas-insulated, U-shaped winding). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8504 31 29 00 |
|---|---|
| HS, 6 digits | 8504 31 |
| CN (EU) | 8504 31 29 |
| HTSUS (USA) | 8504 31 40 95 |
| China customs tariff | 8504 31 10 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
What test voltages does the AGU-800 have?
LI 2100 kV, AC 975 kV and SI 1550 kV, with a creepage distance of 20,000 mm. The unit passed a seismic test at intensity 8 on a 7 m support.
How do the SF6 LVQB units differ from oil-filled ones?
SF6 insulation removes the fire and explosion hazard, dielectric losses and insulation ageing. The LVQB-220 is rated 252 kV and the LVQB-110 126 kV.
What service life is stated for the current transformers?
The manufacturer states over 40 years owing to low losses and low partial discharges. For the LB9-220 the insulation is LI 1050 and AC 460 kV, with a creepage distance of 7812 mm.
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