HT Substation & Distribution

Modular Substation

Aviot provides modular substation concepts in the Electrical distribution system for high voltage equipment, medium voltage equipment, and distribution transformer modules. The modules are designed to allow easy transportation and quick installation times.

Power Transformer

Power transformers are key components in the power distribution system. We offer a complete range of power transformers and related components and parts.

The transformers of rating are up to 5MVA and primary voltage class from 11kV to 66kV are conventionally termed as Power Transformers. These transformers are generally used for stepping down voltage in receiving stations in the distribution network.


  • Ratings: UP TO 20 MVA
  • Voltage Class: UP TO 66 kV
  • No of Phases : 3 Phase
  • Frequency: 50/60 Hz
  • Standards: ANSI, IEEE
  • Tap Changer: OFF CIRCUIT TAP CHANGER, OFFLOAD TAP CHANGER, as per customer requirement

Distribution Transformer

Aviot provides both hermetically sealed, corrugated radiator type and conventional rectangular tank type distribution Transformers. These Transformers are generally used in the distribution network for feeding residential, commercial & bulk consumers.

  • Ratings: UP TO 5 MVA
  • Voltage Class: UP TO 33 kV
  • No of Phases : 3 Phase
  • Frequency: 50/60 Hz
  • Standards: ANSI, IEEE
  • Tap Changer: OFF CIRCUIT TAP CHANGER, OFFLOAD TAP CHANGER, as per customer requirement


  • Highest dielectric insulation property to withstand Lightening Impulse
  • Optimum oven heating under vacuum as to achieve desired compression height and maximum insulation resistance (IR) to windings
  • Adequate ducts between layers, coils, discs for maximum oil flow and reduced hot spot temperature.
  • Step-lap designed CRGO laminations for lower losses and excitation current
  • Pre-compressed Insulation material for minimal moisture absorption
  • Mechanical design to withstand short circuit forces arising during faults

Various types of transformers:

  • Small Power Transformer
  • Medium/ Large Power Transformer
  • Regulating Power Transformer
  • Autotransformer

Small Power Transformer

Small power transformers are used in the distribution network. This technology with our expertise in medium and large power transformers has resulted in a large range of very compact and cost-efficient small power transformers.
Small power transformers are available with off-circuit tap changers and/or on-load tap changers for voltage regulation.

Medium/Large Power Transformer

Large and medium power transformers are used to transmit the power in the grid and to distribute the power in the network. These transformers are usually applied to step down the voltage to the required level. The voltage regulation can take place either through off-circuit tap changers and/or on-load tap changers.


  • Optimum losses
  • Customized Unique design
  • Long life, Low maintenances
  • Overall least lifecycle cost
  • Sustain durability
  • Cost effective concept
  • Environmentally friendly
  • Reduced installation time
  • Exceed public safety standards
  • Includes transformer ON/OFF switch
  • Best field reliability available in the market
  • Based on tried-and-tested technology
  • Meeting the latest IEC technical specifications

Regulating Power Transformer

The voltage regulators are normally connected to the line end of the transmission system to provide additional voltage regulation. The voltage regulators are equipped with wide range voltage variation of on load tap changer. The transformers consist of 2 small active parts (shunt and series transformer). Shunt transformer is connected parallel to the system voltage, and the series transformer is connected serially to the system to boost and buck the system voltage.

Feature: Provides additional voltage regulation


Autotransformers are built with common main winding and a separate low voltage winding. Autotransformers are often used to step up or step down voltages in the 110-115-120 V range and voltages in the 220-230-240 V range.

• Better short circuit strength
• Compact design
• Durability
• Optimum losses
• Voltage regulation can take place through off-circuit tap
• Changers and/or on-load tap changers
• Smaller frame size compared to power transformers

HT Panels:

HT Panel is an electrical distribution board that receives power from Electrical supply generating company and feeds the same to various electrical devices and distribution boards. Such panels are used in industries both for internal and external use and, therefore, they are quite rugged to withstand different climatic conditions. Our HT panels are designed to work with low self-consumption that makes them cost-effective.

HT panels are compact outdoor type systems, which are broadly used in substations. Our product range is prepared from Circuit Breakers or switch fuse on HT side, which protects the equipment from sudden voltage fluctuations also treasured for their high performance, low maintenance, reliable performance, easy to install and safety features.