# Interconnection & Transmission Autotransformers (345-380 kV) - High-Voltage & Transmission Power Transformers

> Verify configuration-specific ratings and compliance in the manufacturer documentation.

> Power/rating scope: 150 MVA - 250 MVA | Voltage scope: 345 kV - 380 kV / 154 kV - 161 kV / 34.5 kV

**Canonical:** https://voltformer.com/category/power-transmission-transformers/interconnected-grid-autotransformers - markdown: https://voltformer.com/category/power-transmission-transformers/interconnected-grid-autotransformers.md

## Parent

[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.

## Sample Products

- [VF-TBEA-PWR-250MVA-380 - TBEA 250 MVA 380/154/34.5 kV Three-Winding Interconnection Autotransformer](https://voltformer.com/product/tbea-250-mva-380-154-34-5-kv-three-winding-interconnection-autotransformer.md)
- [VF-BEST-AUTO-250M-380K - BEST Transformer 250 MVA 380/154/34.5 kV Three-Winding Interconnection Autotransformer](https://voltformer.com/product/best-transformer-250-mva-380-154-34-5-kv-three-winding-interconnection-autotransformer.md)
- [VF-ILJ-AUT-150MVA-345 - Iljin Electric 150 MVA 345/161 kV Interconnection & Transmission Autotransformers (345-380 kV)](https://voltformer.com/product/iljin-150-mva-345-kv-three-phase-transmission-autotransformer.md)
- [VF-HE-AUT-315M-765K - Hitachi Energy 315 MVA 765/345 kV OLTC Autotransformer](https://voltformer.com/product/hitachi-energy-315-mva-765-345-kv-autotransformer.md)
- [VF-GEV-AUT-500M-765K - GE Vernova 500 MVA 765/345 kV Interconnected Autotransformer](https://voltformer.com/product/ge-vernova-500-mva-765-345-kv-autotransformer.md)
- [VF-HE-AUT-500M-765K - Hitachi Energy 500 MVA 765/345 kV Intertie Autotransformer](https://voltformer.com/product/hitachi-energy-500-mva-765-345-kv-autotransformer.md)
- [VF-GEV-AUT-800M-765K - GE Vernova 800 MVA 765/345 kV Interconnected Autotransformer](https://voltformer.com/product/ge-vernova-800-mva-765-345-kv-autotransformer.md)
- [VF-BST-AUT-TER-250M-380 - BEST 250 MVA 380/154/34.5 kV Tertiary-Winding Compensation Autotransformer](https://voltformer.com/product/best-250-mva-380-154-34-5-kv-tertiary-autotransformer.md)

## Technical specializations

- **Three-Winding 380/154/34.5 kV Interconnected Transmission Backbone** - Verify configuration-specific ratings and compliance in the manufacturer documentation.
- **Tertiary-Wound Reactive Power Shunt Reactor Connected** - Verify configuration-specific ratings and compliance in the manufacturer documentation.

## Official sources

- https://webstore.iec.ch/en/publication/599

- **Last reviewed:** 2026-09-13

## RFQ

Use the family-specific tools in [the tool reference](https://voltformer.com/tool-reference.md) and the canonical taxonomy at https://voltformer.com/agent-catalog.json. Sub-category: interconnected-grid-autotransformers. The transformer query's subCategory parameter applies only to transformer families. Authenticate and obtain explicit confirmation before RFQ submission.