765kV substations to boost industries in Tamil Nadu

CHENNAI: With a view to improving quality of power to all types of consumers and taking substantially more additional power load in different regions, Tamil Nadu Transmission Corporation Ltd. (Tantransco) is all set to commission two 765kV sub-stations, and has planned two more for the near future.

They will be fully owned by the discom.

While work on two high-voltage sub-stations at Kolathur in North Chennai and Ariyalur is progressing, two more will come up at Coimbatore and Virudhunagar , said a Tantransco official. Transmission companies install high capacity sub-stations to meet future power demand as well as to meet the high voltage demand from industries .

As of now, there are four 765kV sub-stations in Tamil Nadu, but all are under the PowerGrid Corporation. “With a high capacity sub-station, it is easy to transmit power at high speed. From the consumer end, there will be no voltage drop. Quality of power will be better. From the transmission company’s side, we will be able to lower the line loss, which will help better our finances,” said the official.

At present, Tantransco has 13 sub-stations of 400Kv capacity. Another 11 with the same capacity are owned by the PowerGrid. “In simple terms, a 110kV sub-station can only meet demand up to 80MW, but a 230kV sub-station can meet demand up to 250MW. As the capacity of a sub-station increases, the number of connections and the demand also increases. Quality of power from a 230kV sub-station meeting a demand of 250MW will be inferior to that of a 400kV sub-station,” the official said.

“A 765kV sub-station can meet 3,000MW demand and still provide quality power to the consumers. If industries are set up in areas where lower capacity sub-stations function, the quality of power that domestic consumers in the region get would be poor. But in the case of 765kV sub-station, such voltage drop will not happen,” he said.

The sub-station coming up at Kolathur will be able to meet the demand of many high tension connections in the area. There are a total of 1012 sub-stations of various capacities in the state. Out of them, 83 sub-stations have a capacity of 400kV each.

“Alamathi sub-station near Red Hills meets 70% of Chennai’s power demand. The sub-station has a capacity of 400kV. There are two other sub-stations on the same premises at Alamathi, which primarily cater to domestic consumers,” said the official.