High-Voltage Power Transformers — 1 MVA to 40 MVA Substation Units
Engineered for mega textile complexes, steel rolling plants, sugar mills, and 132kV grid stations across Pakistan. TransfoLine delivers new supply, certified-used units, on-load tap changers (OLTC), and turnkey testing.
Heavy-duty power engineering for continuous plant duty.
TransfoLine power transformers are engineered to deliver steady voltage regulation and extreme short-circuit withstand for 30+ years.
Standard MVA ratings & voltage ratios.
Heavy Industrial Power Transformer Range (1 MVA to 40 MVA)
TransfoLine manufactures, overhauls, and commissions primary substation transformers tailored to utility and captive generation requirements:
| Power Rating | Voltage Class | Cooling | Tap Changer | Typical Application |
|---|---|---|---|---|
| 1.0 MVA – 2.5 MVA | 11kV / 415V | ONAN | Off-Circuit / OLTC | Textile spinning, chemical processing, plastics |
| 3.15 MVA – 5.0 MVA | 11kV / 33kV / 6.6kV | ONAN / ONAF | Motorized OLTC | Large composite mills, steel foundries, flour mills |
| 7.5 MVA – 15 MVA | 33kV / 66kV / 11kV | ONAF (+25%) | Vacuum OLTC | Cement plants, sugar cogeneration, industrial estates |
| 20 MVA – 40 MVA | 132kV / 11kV / 33kV | ONAF / OFAF | In-Tank Motorized | 132kV Dedicated Grid Substation EPC |
Turnkey MVA delivery & grid energization.
-
01
Engineering
Short-Circuit & Load Flow Study
Analyzing fault levels, short-circuit current stresses, vector group matching, and tap regulation requirements.
-
02
Supply / Overhaul
Pure Copper Coil Winding
Continuous disc winding using high-purity electrolytic copper with reinforced axial clamping and vacuum oil drying.
-
03
Heavy Rigging
Civil Plinth Erection & Dressing
Heavy crane mobilization, conservator and radiator installation, high-voltage bushing assembly, and dry nitrogen purging.
-
04
Energized
Grid Pre-Commissioning & DGA
Turns ratio, SFRA core deformation, insulation resistance, protection relay coordination, and NTDC/DISCO grid clearance.
High-voltage power transformer FAQ.
Guidance on large MVA power transformers, tap changers, and 132kV grid connections.
VOLTAGE What is the advantage of an On-Load Tap Changer (OLTC)?
An OLTC adjusts transformer turns ratios automatically while energizing load, counteracting utility grid voltage drops during peak hours to ensure steady 415V power to sensitive plant machinery.
DIAGNOSTICS What testing is required before energizing a 10 MVA transformer?
Standard pre-commissioning testing includes SFRA (Sweep Frequency Response Analysis), Dissolved Gas Analysis (DGA), Tan Delta (C&DF), winding resistance, and transformer turns ratio (TTR).
PROTECTION What fire protection systems are used on large MVA transformers?
TransfoLine installs automatic Nitrogen Injection Fire Protection Systems (NIFPS), deluge water spray networks, and oil soak pit drainage systems to prevent catastrophic substation fires.
WARRANTY What warranty is included on TransfoLine power transformers?
All new and remanufactured power transformers include a comprehensive 12-month operational warranty with guaranteed 24/7 on-site emergency field support.
Power Transformer & Grid Knowledge Hub
Explore in-depth technical guides written by our senior high-voltage design engineers.
Planning a 1 MVA to 40 MVA Substation?
Consult our lead substation engineers for single-line diagram (SLD) reviews, OLTC selection, and itemized project quotations.