EHV Power Transformers
Extra high voltage power transformers for transmission-class applications. Up to 300 MVA, 220–400 kV — KEMA short-circuit certified with advanced directed cooling.
Engineering Features
KEMA Short-Circuit Testing
KEMA-witnessed short-circuit withstand testing for proven reliability under fault conditions.
Technical Data
| Parameter | Range / Value |
|---|---|
| Rated Power | 100 – 300 MVA |
| Primary Voltage | 132 – 400 kV |
| Secondary Voltage | 11 – 36 kV |
| Frequency | 50 / 60 Hz |
| Impedance | 10% – 14% (customizable) |
| Vector Group | As per specification |
| Noise Level | ≤ 75 dB(A) at 1m |
| Total Losses | Per IEC/IEEE guaranteed values |
| Temperature Rise | Top oil ≤ 60K, Winding ≤ 65K |
| Insulation Level | Full BIL / SIL as per class |
Standard range parameters — custom specifications available on request.
Related glossary terms
ENATS 35-1
DNO-approved distribution transformer specification
ENATS 35-2
UK secondary substation transformer standard
G99 Compliant
Engineering Recommendation G99 grid interface
BS EN 60076
British Standard for power transformers
KEMA Certified
Independent short-circuit witness testing
EcoDesign Tier 2
EU 548/2014 efficiency compliance
Extra High Voltage power transformers for the UK transmission system — 100 MVA to 300 MVA at 220 kV, 275 kV and 400 kV. Engineered to BS EN 60076 / IEC 60076 with directed-oil-flow ODAF cooling, on-load tap changers and KEMA short-circuit certification, our EHV portfolio supports National Grid Electricity Transmission interconnection, generation step-up at thermal and offshore-wind plants, and substation autotransformers for SSEN Transmission and SP Transmission.
National Grid 400kV Substation Autotransformers
Offshore Wind Onshore-Substation GSU · UK East Coast
SSEN Transmission 275kV · Scottish Highlands
SP Transmission Cross-Border Interconnect
Thermal & CCGT Power Stations · UK Generation
HVDC Converter-Station Interface Transformers
Where EHV Power Transformers Excel.
National Grid 275/400 kV Substations
BS EN 60076 EHV transformers for National Grid Electricity Transmission 275 kV and 400 kV super-grid substations.
SSE & SP Transmission
EHV transformers for SSEN Transmission and SP Transmission projects across Scotland and the north of England.
UK Offshore Wind Onshore Substations
Grid step-up and interconnection transformers for offshore wind farm onshore substations connecting to the UK transmission network.
Strategic Grid Reinforcement (UK)
EHV auto-transformers for the Great Grid Upgrade, HVDC interconnector substations and pumped-storage projects.
Frequently Asked Questions
Related Knowledge
FAQs, glossary terms and sizing steps mapped to this product.
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