Delhi Transco adds to capacity

The 400-KV ring main around Delhi has been completed with the commissioning of the second circuit between Bamnauli and Ballabhgarh. The Delhi Transco Limited (DTL) will now be able to meet an increased demand.

After the implementation of power reforms and the unbundling of the erstwhile Delhi Vidyut Board, DTL added 105 circuit km of transmission line on the 400 KV system, besides augmenting transformation capacity.

It has stabilised the power supply position, besides improving the voltage profile of the system and strengthening the 400 KV network of the northern region.

The 400 KV ring around Delhi was conceptualised in 1991. The project involved laying 227 circuit kilometres of 400 KV transmission line with the installation of 320 towers at a cost of over Rs 140 crore.

DTL is a state transmission utility (STU) under the Delhi government, and is responsible for establishing and maintaining the 400 KV and 220 KV transmission network in the capital. It also arranges bulk power supply for distribution licensees.

Phase I of the project comprised the commissioning of four 400 KV grid substations in Mandola, Bawana, Bamnauli, and Ballabhgarh along with double-circuit transmission line. Phase II of the project involves commissioning the 400 KV station at Maharani Bagh and Mundka.

The 400 KV Mandola-Bawana double circuit transmission line section was the first to be commissioned in January 1998, and subsequently the section between Bawana and Bamnauli was commissioned in October 2002.

One circuit between Bamnauli and Ballabhgarh was commissioned in August 2003. With the commissioning of the second circuit between the two points, the 400 KV ring main around Delhi is now completed.

The second circuit between Bamnauli and Ballabhgarh has been completed and would provide stability in Delhi and the northern region. The total length of the 400 KV between the two points is 52.8 circuit kilometers. There are 149 towers. The cost of this section is Rs 43 crore.

The line is strung with "Berimis ACSR Quad" conductors with the capacity to transmit 2000 MW of power per circuit. The transmission line is strung with four Bersimis ACSR conductors per phase while most of the transmission system is with twin conductors only.

This design adopted by Transco enables the line to carry a large quantum of power, thereby keeping a big margin for future growth. The load demand in the capital has been increasing by 5"�7 per cent per annum. The peak demand in July 2004 reached 3490 MW.