# TBEA 250 MVA 380/154/34.5 kV Three-Winding Interconnection Autotransformer

> TBEA 250 MVA 380/154/34.5 kV Three-Winding Interconnection Autotransformer belongs to the Interconnection & Transmission Autotransformers (345-380 kV) category and is rated at 250 MVA with 380/154 kV primary/secondary voltage. Application: 380 kV Main Transmission Interconnection System. Final ratings must be verified against the manufacturer datasheet.

> SKU: VF-TBEA-PWR-250MVA-380 | Brand: TBEA (Tebian Electric Apparatus) | Category: Power & Energy Equipment / Transformers / High-Voltage & Transmission Power Transformers / Interconnection & Transmission Autotransformers (345-380 kV)

**Voltformer canonical:** https://voltformer.com/product/tbea-250-mva-380-154-34-5-kv-three-winding-interconnection-autotransformer - markdown version: https://voltformer.com/product/tbea-250-mva-380-154-34-5-kv-three-winding-interconnection-autotransformer.md

## Overview

TBEA 250 MVA 380/154/34.5 kV Three-Winding Interconnection Autotransformer is intended for 380 kV Main Transmission Interconnection System. Configured electrical data: 250 MVA, 380/154 kV primary/secondary voltage, 50 Hz, 3-phase, vector group YNa0d11 and short-circuit impedance 14.5%. Construction: Copper (Cu-Cu); cooling: ODAF/OFAF; loss class: Ecodesign Tier 2. These values support preliminary engineering selection; verify insulation levels, thermal limits, short-circuit duty, installation conditions and applicable standards against the manufacturer datasheet and the site study.

- **Application:** 380 kV Main Transmission Interconnection System
- **Target industries:** National Grid Backbone (Transmission), Nuclear / Thermal Power Switchyards
- **Brand:** [TBEA (Tebian Electric Apparatus)](https://voltformer.com/brand/tbea-energy.md) - TBEA, one of the world's largest transformer manufacturers, delivers world-leading engineering from 1000 kV UHV AC/DC power transformers to SCB18 cast-resin dry-type, S20/S22 ultra-low-loss hermetic a
- **Category:** [Power & Energy Equipment](https://voltformer.com/catalog.md) / **Transformers** / [High-Voltage & Transmission Power Transformers](https://voltformer.com/category/power-transmission-transformers.md): 5 MVA–1000 MVA 110 kV, 154 kV, 380 kV, 500 kV and 1000 kV UHV AC/DC transmission and interconnection power transformers. / [Interconnection & Transmission Autotransformers (345-380 kV)](https://voltformer.com/category/power-transmission-transformers/interconnected-grid-autotransformers.md)

## Technical Specifications

| Property | Value |
|---|---|
| Rated power | 250 MVA |
| Primary / secondary voltage | 380 kV / 154 kV (±12 x 1.25% (on-load tap-changing)) |
| Frequency / phases | 50 Hz / 3-phase - YNa0d11 |
| Short-circuit impedance (Uk) | 14.5% |
| No-load loss P0 | 78.00 kW |
| Load loss Pk | 490.0 kW |
| Calculated efficiency (power factor = 1) | 99.77% at 100% load; 99.84% at 50% load |
| Loss class | Ecodesign Tier 2 |
| Windings | Copper (Cu-Cu) - cooling: ODAF/OFAF - insulation: Class A |
| Temperature rise | 65 K - sound pressure: 72 dB(A) |
| Mass and dimensions | 240000 kg - 9800×5800×8200 mm |
| Enclosure | IP55 - wheel gauge: 1435 mm |
| LI / AC withstand | 1425 kV peak / 560 kV rms - partial discharge: 20 pC |
| Environment | -25°C / +40°C; altitude ≤ 1000 m |
| Core steel | CRGO Laser-Treated Grain-Oriented Silicon Steel (23ZDMH85 / Baosteel B23R085) |
| Bushings / terminals | RIP (Resin Impregnated Paper) Dry Condenser High-Voltage Bushing |

## Standards

- IEC 60076
- TEİAŞ 380 kV special specification
- IEEE C57
- KEMA type-tested

## Accessories

**Included:** 380 kV RIP Dry-Type Bushings, Advanced DGA & Online Gas Analysis, Vacuum OLTC, Dual Buchholz Relays
**Optional:** Smart Transformer SCADA Integration Package, Automatic Water Spray Fire Fighting Equipment

## Official sources

- https://en.tbea.com/product_list/48.html

- **Source scope:** manufacturer-family
- **Last reviewed:** 2026-09-13

Manufacturer portfolio/family source. Confirm the exact order code, guaranteed ratings and project-specific options against the current OEM datasheet before procurement or an SLD study.

## Pricing & Logistics

- Pricing type: RFQ (On Request) - Indicative range: $1,750,000 – $2,100,000 USD
- Delivery time: 2–8 weeks (may vary depending on technical configuration, factory capacity and destination) - Warranty: 36 months
- Compliance candidates: IEC 60076, TEİAŞ 380 kV special specification, IEEE C57, KEMA type-tested. Verify applicability and conformity against the exact offered model and project jurisdiction.

## RFQ

Request a formal factory quotation via Voltformer RFQ:

```json
POST https://voltformer.com/api/v1/rfq
{"companyName":"Example Energy","email":"procurement@example.com","items":[{"skuOrId":"VF-TBEA-PWR-250MVA-380","quantity":1}]}
```

Full catalog JSON: https://voltformer.com/agent-catalog.json - OpenAPI: https://voltformer.com/openapi.json