The Power Grid Corporation of India (PGCIL), a Maharatna CPSE under Ministry of Power, has upgraded New Mariani sub-station in Assam from 220 kV switching station to 400/220 kV sub-station with two x 500 MVA transformation capacity, two x 125 MVA (reactive) power compensation along with other associated bays under North-Eastern Region Strengthening Scheme (NERSS-VI) project.
In March 2013, the new Mariani sub-station had been commissioned in Jorhat District with 20 MVAR reactive power compensation capacity.
With this upgradation, connectivity at 400 kV voltage level between 400 kV Misa sub-station, 400 kV new Mariani sub-station and 400 kV Kohima sub-station has been established.
It has now become the first 400 kV sub-station of upper Assam, which will serve as a key station for catering to augmentation of power in upper Assam, Nagaland, Manipur and the entire North-Eastern Region. This capacity addition will add efficiency and robustness, leading to supply of reliable power.
The project has been commissioned timely despite limitations in wake of COVID-19 pandemic, difficult soil and weather conditions. The bays and additional 400 kV D/C line section for upgradation of Misa-New Mariani Line from 220 kV to 400 kV level are now under commercial operation.
PGCIL presently has 264 sub-stations and 172,104 ckm and 4,64,292 MVA of transformation capacity. With the adoption of the latest technological tools and techniques, enhanced use of automation and digital solutions, PGCIL has been able to maintain average transmission system availability more than 99 percent.
