Power Transformers

Power transformers are electrical instruments used in transmitting electrical power from one circuit to another without changing the frequency. They operate by the principle of electromagnetic induction. They are used in transmitting electrical power between generators and distribution primary circuits.

Power Transformer plays a vital role in power networks, its life and performance play a significant role in the Electrification, transmission and has direct impact on the grid stability, We manufactures Power Transformers ensuring quality at each stage of manufacturing and didn’t compromise on the quality terms. Each Power transformers undergoes quality standard and internationally accepted norms and regulations, Trenex Power Transformers are well known for their quality, excellent performance, reliability on the different environmental conditions and responsive after Sales & Service.

We offer wider range of Power Transformer up to 100MVA, 220kV Class. Our Manufacturer has NABL Acc LAB and we have conducted test at KEMA/CPRI /STL labs and is also approves by PGCIL & NTPC.

The high quality Standard setup by the company are appreciated by our customers in India and Abroad, Standards which are applied to development, manufacturing, installing and commissioning of power transformers for power stations, special purpose transformers for industry fields, reactors and accessories.

Solar transformer

Solar or Wind power transformers have some very unique characteristics that require careful consideration. Their primary purpose is to transform voltage but in order to do so properly, quite a few other characteristics need consideration. From harmonics to voltage disruption to even simply how often a transformer is loaded off and on in a single day, any number of these considerations, if not properly managed, could have a big impact on the efficiency and safety of wind or solar power transformer.

There are different types of solar transformers including distribution, Substation, Pad mounted and grounding.

Solar Applications

We understands the needs of the solar developers and has successfully designed and shipped transformers for power distribution applications in a solar farm using PV modules in different continents. We have been successfully meeting the stringent specifications of customer and have designed with low losses but high efficiency standards to meet the industry‘s stringent demands.


Solar transformer up to 12.5 MVA with voltage class range: – HV -11, 22 & 33 and LV as per customer specifications with vector group Dy11Y11, Dy11, Y11y11, Dy5y5y5 or as per customer specification

Voltage step up from the inverter output to the MV feeding network

Galvanic isolation between the solar inverter and the feeding network

High mechanical strength LV winding comprise of 2 winding made of Al/Cu both connected in WYE (Y) without neutral point

Cooling system both ONAN & ONAF

Robust and oil tight mechanical construction with customized overall dimensions. High Quality surface protection.

Protection and monitoring with devices that are oil level indication, gas detection, pressure and temperature control.

Distribution Transformer

Trenex manufactures a wide range of distribution transformers ranging from 25 KVA to 5000 KVA with all voltage class and up to 33 KV. These transformers can be free breathing, fitted with a conservator or hermetically sealed. The liquid filled range can be cooled by either tank – mounted plate radiators or by corrugations on the side of their tanks. The later, being known as conventional type transformer. Free breathing units, with or without conservator are normally oil-filled, while hermetically sealed transformers can be filled with either oil or one of several low flammability synthetic fluids. Both types can be supplied with HV and LV Switchgear and incorporated into substations. Advanced quality management, combined with exhaustive testing, assures our customers of the most reliable performance.

Hermetically sealed transformers are totally maintenance free and are particularly suited for use in exposed outdoor environments such as moisture, salt or dust laden atmospheres. They are used extensively in chemical plants, oil and gas terminals where poor accessibility makes regular maintenance impracticable. Transformers immersed in synthetic coolants are suitable for use indoors with adequate ventilation or near to the load center where oil would not be considered environmentally acceptable.

Unitized Package Substation

Unitized Transportable Substation is used for feeding power from high voltage to low voltage in open cast mines, construction sites, metro cities etc. The substation is compact in size, suitable for frequent shifting and for use in outdoor locations. The substation is installed and mounted on skid frame or wheels or channels and is provided with lifting hooks. The unitized substation comprises of the following main components:

Vacuum Circuit Breaker panel in outdoor enclosure upto 11KV 1250A complete with CT, PT, Relay & Instrument chamber. The outdoor panel is directly coupled with HT Flange of the transformer with copper busbars. The incoming of the HT Panel is provided either with Plug Socket or Cable box. Alternatively a Load Break Switch or a Ring Main Unit can also be coupled with the HT bushing of the transformer.

Outdoor type Transformer upto 1600KVA 11KV-6.6KV-3.3KV/415V, DYn11, ONAN with off load tap changing switch and standard fittings as per IS/IEC standards. The transformer has HT Flange with bushings to be coupled directly with the outgoing of the HT Panel and LT flange with the incoming of LT Panel. The transformer can be either Oil immersed type or Dry type with Nomex insulation. With Dry type transformer the total unit can be housed in a single outdoor type enclosure in place of three separate enclosures.

LT Panel is outdoor type comprising of one or more air circuit breaker or MCCB either in single or board formation suitable for a System Voltage of 415V,3-Phase 50 C/S. Incoming of LT Panel is directly coupled with the LT flange of the transformer. The outgoing is either Cable box or Plug & Socket arrangement for feeding power to LT equipment.


Easy to operate, safe.

Compact portable & ready to install.

Designed for better cooling.

All fasteners are SS/Steel Zinc plated.

Transformer dry type or oil cooled

Low maintenance

Customer made design

Superior aesthetics

All compartments are provided with illumination

In accordance with IEC 62271 , IEC 1331

Suitable for all weathers

Design Combinations –


Ring Main Unit

Vacuum Circuit Breaker

Load Break Switches n SCADA Interface


Oil Cooled Transformer or Cast Resin dry type or VPI dry type

Low losses design n Corrugated tank

Tap changer


Air circuit breaker

Molded case circuit break

Fuse units


Metering with SCADA option