Power Grid Corporation of India Ltd (PGCIL), in FY25, commissioned a 765kV digital substation at Navsari in Gujarat. This EHV substation is the first digital substation in the world at 765kV level, according to R.K. Tyagi, CMD, PGCIL.
Addressing an investor conference recently, the PGCIL CMD explained that the Navsari substation is the highest-voltage digital substation anywhere in the world.
R.K. Tyagi explained that the Navsari digital substation is used for evacuation of power from Khavda region in Gujarat to Maharashtra, and also to other parts within Gujarat. Through the Navsari substation, power is transferred to Padghe in Maharashtra and to areas like Ahmedabad, Magarwada and Kala, within the state of Gujarat.
This technically-advanced substation is equipped with remote monitoring facility and can be monitored from anywhere – even from outside India.
Highlighting the technical advantage of the Navsari substation, the top PGCIL official explained that at 765kV level there is considerable EMI (electromagnetic interference) that can cause malfunctioning of the substation. Since the 765kV Navsari substation uses fibre optics and digital technology, the risk of malfunctioning becomes negligible, positively contributing to grid stability and resilience, Tyagi noted. [According to reliable sources, EMI refers to unwanted electromagnetic disturbances that can disrupt the operation of electronic devices.]
765kV tower erected in a single day
R.K. Tyagi highlighted that PGCIL during FY25 set a record of erecting a 765kV transmission line tower in a single day. This 765kV DA-type tower with 37.4 tonnes of material is part of the 765kV Banaskantha-Ahmedabad line in Gujarat. In normal course, the output of a transmission tower gang is 8-10 tonnes in a day. However, with PGCIL’s superior project management techniques, the feat of 37.4 tonnes could be achieved in a single day, Tyagi noted. [A “DA”-type tower, it is learnt, is a “suspension” tower where conductors are held in suspended position so as to allow conductors to sag between towers.]
The PGCIL CMD also discussed the 765kV Sikar substation in Rajasthan that was commissioned in a record time of 9-10 months from the time of land acquisition. Such expeditious commissioning could very well be a global achievement, Tyagi felt. He added that PGCIL was putting all effort in improving this record by targeting to commission the upcoming 765kV Dausa substation in Rajasthan in even lesser time. The substation is expected to commission in 1-2 months.
Towards project excellence
The PGCIL top official noted that a number of initiatives are being taken by PGCIL towards project excellence with a final objective of reducing project execution time. These include setting up of a centralized project monitoring control centre at the corporate headquarters, Gurugram; putting up skilled development centres especially for transmission tower erection; setting up dedicated cells for addressing land acquisition and right-of-way issues at project sites; introducing a bulk procurement strategy for key equipment with a view to cutting down lead time; introducing advanced tower erection techniques, such as crane-based erection for EHV towers; drone-based stringing; use of pre-fabricated firewalls for transformers and reactors at substations to reduce construction time, etc.
Featured photograph shows a schematic representation of PGCIL’s 765kV Navsari digital substation while smaller picture shows the 765kV DA-type tower discussed in the story. Both installations are located in Gujarat. (Photos: PGCIL).
