AT / ATV — high-speed on-load tap changers (OLTC) up to 66 kV (132 kV at the neutral), 300–400 A
AT and ATV single-compartment three-phase on-load tap changers (OLTC) with high-speed resistor transition, for external mounting on the transformer tank. Voltage up to 66 kV at the line end and up to 132 kV at the neutral, current 300 and 400 A. For power transformers of 11–132 kV.
- Voltage
- up to 66 kV (52 kV star/delta) at the line end; 132–145 kV at the neutral
- Rated current
- 300 A; 400 A (linear regulation)
- Positions
- up to 17 (16 steps) linear; up to 33 (32 steps) reversing/coarse-fine
- Principle
- high-speed resistor transition, single compartment
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
AT and ATV are single-compartment three-phase OLTCs with high-speed resistor transition for external (flange) mounting on the tank of a power transformer. The transition between taps takes place without breaking the load circuit. The oil in the diverter switch compartment is always separate from the oil in the main tank, so arcing products do not enter the transformer oil. A single-phase version is also available for single-phase windings. Control is fully automatic or manual, the oil volume is small and maintenance is simple.
Voltage is up to 66 kV at the line end of the winding and up to 132 kV (145 kV for a star-connected winding) at the neutral. A version for 52 kV windings, star or delta connected, is provided. Rated current is 300 A, and 400 A for linear regulation. Mounting is horizontal (AT) or vertical (ATV), depending on the layout on the transformer tank.
The maximum number of positions is 17 (16 steps) with linear regulation (15 is also possible for a linear scheme) and 33 (32 steps) with reversing or coarse-fine regulation. The AT type OLTC operates with reverse power flow at full load. This is needed at substations with distributed generation and storage, where the direction of flow changes. The choice of regulation scheme determines the number of positions, so it is agreed at the stage of ordering the transformer. The small oil volume and simple design reduce operating costs.
Manufacture is to IEC 60214 and other national and international standards. It is used with 11–132 kV power transformers of network companies, industry, renewables and oil and gas. The company's management system is certified by AFNOR UK to ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018. Certification covers design, manufacture, testing, installation, commissioning, servicing and repair of power, traction and special transformers, reactors and OLTCs with control systems.
Transformers are fully assembled and tested at the factory in Loughborough (United Kingdom). The test facility, which complies with IEC (BS EN) and ENA, performs routine and type tests of transformers up to 170 kV, including impulse, temperature rise, SFRA, and measurement of partial discharge, losses and noise level.
Technical specifications
| Voltage | up to 66 kV (52 kV star/delta) at the line end; 132–145 kV at the neutral |
|---|---|
| Rated current | 300 A; 400 A (linear regulation) |
| Positions | up to 17 (16 steps) linear; up to 33 (32 steps) reversing/coarse-fine |
| Principle | high-speed resistor transition, single compartment |
| Mounting | external flange; horizontal (AT) or vertical (ATV) |
| Versions | three-phase and single-phase |
| Features | reverse power flow at full load; diverter switch oil separate from the tank |
| Standard | IEC 60214 |
Request a price and lead time
AT / ATV — high-speed on-load tap changers (OLTC) up to 66 kV (132 kV at the neutral), 300–400 A. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What voltage and current are the AT and ATV OLTCs rated for?
Voltage up to 66 kV at the line end of the winding and up to 132 kV (145 kV for a star-connected winding) at the neutral. Rated current is 300 A, and 400 A for linear regulation.
How many positions does the tap changer have?
Up to 17 positions (16 steps) with linear regulation and up to 33 positions (32 steps) with reversing or coarse-fine regulation.
To which standard is the OLTC made and how is it mounted?
Manufacture is to IEC 60214. Mounting is by flange, external on the transformer tank, horizontal for AT or vertical for ATV.
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