Transformers

Oil‑Filled and Power Transformers

• High‑Power Industrial Rectifier/Power Transformers (Neeltran & NWL) – Neeltran manufactures custom oil‑filled rectifier transformers from 100 kVA to 50 MVA with input voltages up to 69 kV; dry‑type and water‑cooled units cover 5–10,000 kVA, with outputs up to 300 kV and frequencies up to 50 kHz. NWL builds dry‑type transformers up to 10,000 kVA and water‑cooled units up to 25,000 kVA with output voltages to 300 kV, input voltages up to 34.5 kV, isolation voltages up to 250 kV (oil) and frequencies up to 200 kHz. These products serve rectifier duty, step‑up/inter‑phase and multi‑pulse applications.

• Utility‑Scale Power Transformers (Comtrafo) – Comtrafo’s oil‑filled power transformers, autotransformers and reactors offer 5 MVA to 250 MVA power ratings with high‑voltage classes from 7.2 kV up to 345 kV and low‑voltage classes up to 145 kV. They use 99.99 % pure copper windings, grain‑oriented silicon‑steel cores and carbon‑steel tanks with anti‑corrosion coatings. Vapor‑phase drying and controlled assembly ensure moisture‑free insulation, and units can be cooled 

• Pad‑Mounted Transformers (Comtrafo) – Three‑phase pad‑mounted transformers for compact installations are rated 75 kVA to 10 MVA. Standard high‑voltage classes are 7.2–36 kV and low‑voltage classes 1.2–15 kV. These units are designed for shopping centers, schools, hospitals, wind/solar farms and energy‑storage systems and feature copper or aluminum windings, grain‑oriented cores, oil‑ or silicone‑filled tanks and robust anti‑corrosion coatings.

• Compact Oil‑Filled Transformers (Comtrafo) – Compact sealed‑tank transformers for space‑constrained sites (cabins or substations) are available from 225 kVA to 10 MVA. High‑voltage classes include 7.2, 15, 25 and 36.2 kV, while low‑voltage classes cover 1.2, 7.2 and 15 kV. They share the same high‑quality windings and steel‑tank construction as the larger power transformers.

Distribution and Dry‑Type Transformers

• Distribution Transformers (Comtrafo) – Comtrafo builds distribution transformers for pole‑mount, platform or underground use with power ratings 500 kVA to 15 MVA and high‑voltage classes 7.2–36 kV; low‑voltage classes extend to 1.2–36 kV.These units use copper or aluminum windings, grain‑oriented steel cores and carbon‑steel tanks with anti‑corrosion coatings. They can be installed indoors or outdoors, including harsh environments, and can be filled with mineral oil or special biodegradable fluids.

• Dry‑Type Epoxy‑Cast Transformers (Comtrafo) – Encapsulated resin‑cast units are offered from 300 kVA to 50 MVA with high‑voltage classes 1.2–52 kV and low‑voltage classes 1.2–36.2 kV. Vacuum‑casting eliminates air pockets, resulting in partial‑discharge‑free insulation. Cores use oriented silicon‑steel step‑lap laminations for low losses and quiet operation. Enclosure protection ranges from IP‑00 to IP‑6X for indoor or outdoor placement.

• Neeltran Dry‑Type and Cast‑Coil Transformers – Neeltran produces dry‑type and water‑cooled transformers from 5 kVA to 10,000 kVA (inputs up to 25 kV) and cast‑coil transformers up to 20 MVA (inputs to 35 kV). The company also designs high‑frequency transformers up to 2,000 kVA at 50 kHz, and oil‑filled transformers up to 50 MVA. Features include 100 % copper windings, 220 °C insulation systems and options for oil, air, epoxy, gas or water cooling. Vacuum‑pressure impregnation and fan‑cooling options enhance reliability and thermal performance.

Inductors, Reactors

• NWL Industrial Inductors – NWL designs air‑ or iron‑core inductors up to 5,000 kVAR with input voltages up to 15 kV. These can be air‑ or water‑cooled and filled with mineral oil, silicone or FR3 fluid.Neeltran Chokes, Reactors and Special Transformers – Neeltran manufactures air‑ or iron‑core chokes and reactors rated up to 25 kV and 20,000 A. It offers power packs combining transformers and saturable reactors (10–2,500 kVA) with air or water cooling, phase‑changer transformers (5–2,500 kVA) for furnace and heating applications, and dry rectifier transformers up to 10,000 kVA with DC outputs up to 50 kV. High‑frequency transformers cover 25 Hz to 10 kHz at 2,000 kVA and 10 kHz to 50 kHz at 100 kVA.

• Electrostatic Precipitator T/R Sets (NWL) – NWL supplies linear transformer‑rectifier (T/R) sets for electrostatic precipitators. Standard designs offer peak output voltages of 70–110 kV and output currents 200–1,500 mA; custom designs reach 135 kV and 3,000 mA. The company also refurbishes existing T/R sets, replacing all components except the core and tank and providing a 24‑month warranty.