Sub-station Transformers

This type of transformer is used in sub stations to transfer the incoming voltage to the next voltage level. It can be system or auto transformer with two/three windings. In general it is equipped with On load tap changers and are connected to transmission grids by bushings and cables.

The system/auto transformer is built in core form. HV/LV windings are galvanically separated for system transformer while they are Auto connected for auto transformer.

Generator Transformers

This is a type of Power Transformer where the LV winding is connected to the generator through the bus duct and HV winding to the transmission system. In addition to the features of Power Transformer, our Generator Transformer is designed to withstand over voltage caused by sudden load throw off from the generator. It is built as a single or three phase unit and located in power stations.

Unit Auxiliary Transformers (UAT)

The Unit Auxiliary Transformer is the Power Transformer that provides power to the auxiliary equipment of a power generating station during its normal operation. This transformer is connected directly to the generator out-put by a tap-off of the isolated phase bus duct and thus becomes cheapest source of power to the generating station.

It is generally a three-winding transformer i.e. one primary and two separate secondary windings. Primary winding of UAT is equal to the main generator voltage rating. The secondary windings can have same or different voltages i.e. generally 11KV and or 6.9KV as per plant layout.

132/25 KV Single Phase Traction Transformer

This transformer is installed in a traction sub-stations along side the rail track and is used to feed 25KV AC power to railway electric locomotives.

The 132 KV winding is connected to two nominated phases of incoming three phase lines and on the secondary side, one terminal of 25 KV winding is connected to the traction overhead equipment while the other is solidly earthed to the running traction rails. This transformer is designed to meet overloads up to 200% for specified duration and dynamic/thermal short circuit of 0.5sec and 5 sec respectively.