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Home / Facilites - VOLTAMP POWER LLC


With strong fundamentals in design and manufacture, Voltamp Power L.L.C proudly announced the new the world-class green-field 220kV Power Transformer Manufacturing Plant a one of- its-kind unit, is operational in Phase V, Sohar Industrial Area and manufacturing Power transformers up to 315 MVA of 220kV Class in Oman.

Its technology can be seamlessly upgraded at a later date, to manufacture Power Transformers up to 400kV Class also, a unique feat in the MENA region. The new factory has been built to the latest global standards, in technical collaboration with Tatung Company of Taiwan. Tatung, a well respect and diversified company, is the leader in several technologies including digital consumer products like LCD TVs and industrial products like cables, gas insulated switchgear, motors and transformers. Their products are exported all over the world including Japan, USA and Australia. Tatung has been making transformers for 46 years and their transformers are known for their quality, reliability, as well as for rugged construction. Currently their transformer range extends up to 800 MVA, 345 kV class.

Cutting Edge Design

Voltamp Power LLC uses powerful and highly sophisticated software tools to design and develop the power transformers. These tools help in ensuring optimum electrical & mechanical efficiency and determine eddy current losses & short circuit forces accurately. 3-D modelling software enables to view virtual prototypes of transformer including active part and electrical clearances. This software programme helps in detailed analysis of design and consistent results to calculate:

  • Oil flow & temperature rise
  • Leakage flux distribution, eddy current losses and short circuit electro-magnetic forces
  • Impulse voltage distribution
  • Mechanical strength of tank
  • Voltage stress analysis
  • Software for core designing, etc.


facilites_1Hi-B Grade Cold Rolled Grain Oriented (CRGO) silicon steel laminations, directly procured from the mill, confirm excellent quality. Step lap core construction without core bolts further ensures low no-load loss, less noise and low exciting current. The limb and yoke is bound by non-conducting resin glass tape which provides rigidity to the core and uniform circularity for inner most winding.


facilites_2Windings are made in a clean, dust free andair-conditioned environment. The windings are designed to withstand very high short circuit through fault currents, uniform surge voltage distribution and effective heat dissipation, qualities that are important to achieve product reliability.

facilites_3High voltage windings are generally disc type which has better short circuit withstand capability, uniform surge voltage distribution and effective heat dissipation. Continuously transposed conductor is extensively used for making the windings to achieve low eddy loss. The windings are produced on PLC controlled vertical and horizontal winding machines to meet the exact dimensions. Adjustable mandrels ensure compliance to designed winding diameter

Core Coil Assembly

Core and windings are assembled in the main assembly area. Extra care is taken for connections of winding leads, using proper terminal gears to tap changer and leads. Trained personnel make the appropriate brazing or crimping connections.


Tanks are fabricated from the best quality mild steel sheets by electric welding. Finite element analysis software is used to obtain optimum tank construction and appropriate reinforcement. This ensures the capability of tanks to withstand different mechanical stresses such as external pressure during vacuum oil filling, vibration during transportation, gravity in lifting and oil & internal pressure caused by temperature rise.

Drying Process

Moisture in insulation materials of winding is removed by application of heating and vacuum in an oven separately before assembly of the core and coil. Core-coil Voltamp Power LLC at Sohar is equipped with a ‘state-of-the-art’ high voltage testing lab. Power transformers produced in Voltamp Power LLC are subjected to routine, type and special tests in accordance with IEC 60076/ANSI(C-57-12-90) to ensure very high standards of quality.


The test facility is well equipped to perform:

  • Lightening & Switching impulse test
  • Induced over-voltage test (ACSD and ACLD with PD measurements)
  • Power frequency withstand voltage test
  • Temperature rise test
  • Measurement of noise level
  • Measurement of harmonics and zero sequence impedance
  • Capacitance and tan delta measurement;
  • SFRA (Sweep Frequency Response Analysis), etc.

This testing facility is equipped to carry out all tests for transformers up to 315MVA 400kV Class.

Quality Control

Voltamp Power transformers are made under stringent quality control which covers all the stages of manufacture, from design, selection of vendors, sourcing of raw materials, inspection on receipt of raw materials, measurement and tests after each manufacturing stage and a final acceptance test in the presence of customers or their nominated representative assembly is dried in a high-tech PLC controlled Vapor Phase Drying (VPD) plant. This ensures thorough and uniform drying, resulting in dry and clean core coil assembly, leading to longer transformer life.

In-house Handling and Transportation

The entire power transformer facility is epoxy floored. Air coasters are used to move the windings, sub-assemblies and complete transformers, facilitating jerk free movement inside the plant which is essential for the safety and long life of transformers. For transportation to site Voltamp suggests use of hydraulic axles for transformers weighing beyond 60 tons and use of impact recorders to measure shocks during transit.

Installation and After Sales Support

Voltamp Power has a dedicated team of engineers to provide service during installation and commissioning. The Company is committed to attend any calls within 24 hours. Voltamp Power is also planning to keep standby standard power transformer units at its facility so that they can be mobilized to site within 24 hours of requirement. Voltamp Power is also keen to set up a dedicated team to ensure timely and efficient repair of other makes of transformers at its facility.