# Substation Step-Down Power Transformers (110-330 kV) - High-Voltage & Transmission Power Transformers

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

> Power/rating scope: 25 MVA - 250 MVA | Voltage scope: 110 kV - 330 kV / 13.8 kV - 110 kV

**Canonical:** https://voltformer.com/category/power-transmission-transformers/substation-step-down-power-transformers - markdown: https://voltformer.com/category/power-transmission-transformers/substation-step-down-power-transformers.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-31.5MVA-110 - TBEA 31.5 MVA 110/34.5 kV Substation Step-Down Power Transformer (OLTC)](https://voltformer.com/product/tbea-31-5-mva-110-34-5-kv-substation-step-down-power-transformer-oltc.md)
- [VF-TBEA-PWR-50MVA-154 - TBEA 50 MVA 154/34.5 kV On-Load Tap-Changing (OLTC) High-Voltage Power Transformer](https://voltformer.com/product/tbea-50-mva-154-34-5-kv-on-load-tap-changing-oltc-high-voltage-power-transformer.md)
- [VF-TBEA-PWR-100MVA-154 - TBEA 100 MVA 154/34.5 kV High-Voltage Transmission Grid Power Transformer](https://voltformer.com/product/tbea-100-mva-154-34-5-kv-high-voltage-transmission-grid-power-transformer.md)
- [VF-ABB-PWR-50MVA-154 - Hitachi Energy / ABB TrafoStar 50 MVA 154/34.5 kV High-Voltage Power Transformer](https://voltformer.com/product/hitachi-energy-abb-trafostar-50-mva-154-34-5-kv-high-voltage-power-transformer.md)
- [VF-BST-PWR-50MVA-154 - BEST Transformer 50 MVA 154/34.5 kV High-Voltage Step-Down Power Transformer (TEİAŞ Compliant)](https://voltformer.com/product/best-transformer-50-mva-154-34-5-kv-high-voltage-step-down-power-transformer-tei-as-compliant.md)
- [VF-XD-PWR-240M-330K - China XD Group 240 MVA 330/110/35 kV Three-Winding Power Transformer (OLTC)](https://voltformer.com/product/china-xd-group-240-mva-330-110-35-kv-three-winding-power-transformer-oltc.md)
- [VF-JSHP-DRY-40M-110K - Jiangsu Huapeng (JSHP) 40 MVA 110/35 kV Epoxy Cast Resin Dry-Type Power Transformer](https://voltformer.com/product/jiangsu-huapeng-jshp-40-mva-110-35-kv-epoxy-cast-resin-dry-type-power-transformer.md)
- [VF-CHINT-SZ11-63M-110K - CHINT SZ11 63 MVA 110/34.5 kV On-Load Tap-Changing Power Transformer](https://voltformer.com/product/chint-sz11-63-mva-110-34-5-kv-on-load-tap-changing-power-transformer.md)

## Technical specializations

- **On-Load Tap Changer Automatic Voltage Regulation (OLTC)** - Verify configuration-specific ratings and compliance in the manufacturer documentation.
- **De-Energized Tap Changer Step-Down Power (NLTC)** - 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: substation-step-down-power-transformers. The transformer query's subCategory parameter applies only to transformer families. Authenticate and obtain explicit confirmation before RFQ submission.