# Toshiba Energy Systems 250 MVA 275/66 kV Substation Step-Down Power Transformers (110-330 kV)

> Toshiba Energy Systems 250 MVA 275/66 kV Substation Step-Down Power Transformers (110-330 kV) belongs to the Substation Step-Down Power Transformers (110-330 kV) category and is rated at 250 MVA with 275/66 kV primary/secondary voltage. Application: 275 kV Metropolitan and Regional Transmission Substations. Final ratings must be verified against the manufacturer datasheet.

> SKU: VF-TOS-PWR-250MVA-275 | Brand: Toshiba Energy Systems | Category: Power & Energy Equipment / Transformers / High-Voltage & Transmission Power Transformers / Substation Step-Down Power Transformers (110-330 kV)

**Voltformer canonical:** https://voltformer.com/product/toshiba-250-mva-275-kv-low-noise-power-transmission-transformer - markdown version: https://voltformer.com/product/toshiba-250-mva-275-kv-low-noise-power-transmission-transformer.md

## Overview

Toshiba Energy Systems 250 MVA 275/66 kV Substation Step-Down Power Transformers (110-330 kV) is intended for 275 kV Metropolitan and Regional Transmission Substations. Configured electrical data: 250 MVA, 275/66 kV primary/secondary voltage, 50 Hz, 3-phase, vector group YNd11 and short-circuit impedance 13.5%. Construction: Copper (Cu-Cu); cooling: ONAN/ONAF; loss class: IEC / JEC SOTA. 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:** 275 kV Metropolitan and Regional Transmission Substations
- **Target industries:** Urban Step-Down Substations, High-Voltage Transmission Grids, Metropolitan Power Distribution Centers
- **Brand:** [Toshiba Energy Systems](https://voltformer.com/brand/toshiba-energy-systems.md) - Toshiba Energy Systems is an ultra-high-voltage power engineering pioneer, manufacturing 1000 kV UHV transformers, solid-insulated vacuum switchgear (SIS), and digital substation solutions.
- **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. / [Substation Step-Down Power Transformers (110-330 kV)](https://voltformer.com/category/power-transmission-transformers/substation-step-down-power-transformers.md)

## Technical Specifications

| Property | Value |
|---|---|
| Rated power | 250 MVA |
| Primary / secondary voltage | 275 kV / 66 kV (±10 x 1.25%) |
| Frequency / phases | 50 Hz / 3-phase - YNd11 |
| Short-circuit impedance (Uk) | 13.5% |
| No-load loss P0 | 68.00 kW |
| Load loss Pk | 480.0 kW |
| Calculated efficiency (power factor = 1) | 99.78% at 100% load; 99.85% at 50% load |
| Loss class | IEC / JEC SOTA |
| Windings | Copper (Cu-Cu) - cooling: ONAN/ONAF - insulation: Class A (105°C) |
| Temperature rise | 65 K - sound pressure: 62 dB(A) |
| Mass and dimensions | 195000 kg - 8600×4800×6500 mm |
| Enclosure | IP55 - wheel gauge: 1800 mm |
| LI / AC withstand | 1050 kV peak / 460 kV rms - partial discharge: 30 pC |
| Environment | -25°C / +45°C; altitude ≤ 1000 m |
| Core steel | CRGO Laser-Treated Grain-Oriented Silicon Steel (23ZDMH85 / Baosteel B23R085) |
| Bushings / terminals | RIP Kondenser Bushing |

## Standards

- IEC 60076
- IEEE C57
- JEC

## Accessories

**Included:** Vacuum OLTC, Buchholz Relay, Configuration-specific technical value, Configuration-specific technical value
**Optional:** Configuration-specific technical value

## Official sources

- https://toshiba.com/tai/energy-systems/

- **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: $2,100,000 – $2,450,000 USD
- Delivery time: 2–8 weeks (may vary depending on technical configuration, factory capacity and destination) - Warranty: 36 months
- Compliance candidates: IEC 60076, IEEE C57, JEC. 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-TOS-PWR-250MVA-275","quantity":1}]}
```

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