Tamil Nadu Transmission Corporation

The Tamil Nadu Transmission Corporation Limited (TANTRANSCO) (தமிழ்நாடு மின் தொடரமைப்புக் கழகம் (வரையறுக்கப்பட்டது)) is an electric power transmission system operator owned by Government of Tamil Nadu. It was established in November 2010, as a result of restructuring the Tamil Nadu Electricity Board. It is a subsidiary of TNEB Limited.

Substations
The TANTRANSCO maintains all the substations in Tamil Nadu apart from the Power Grid Corporation of India Limited (PGCIL). These substations fall under one of the following categories:
 * 400/230 kV substations.
 * 230/110 kV substations.
 * 110 kV substations.
 * 33 kV substations.

less than this kV transmissions as 22 kV and 11 kV are used for distribution.

66/11 kV substations were in use earlier. This is no longer the case anymore.