Patrolling high-voltage electricity transmission networks by road and manually operating sub-stations are passé. Beginning this month, the Rs 12,700-crore PowerGrid Corporation of India Ltd (PGCIL) will roll out a scheme for air-surveillance of its vast 1,02,540 circuit km electricity transmission network and remotely control the 173 sub-stations.
The aerial patrolling, which costs Rs 4,500 a km, will replace the existing system of patrolling by road.
"We expect to start air-surveillance on the Delhi-Agra line by December 10," R.P. Sasmal, Director (Operations) of PGCIL, told media persons.
The scheme will next be launched in the Agra-Gwalior section, passing through the Chambal ravine. PGCIL hopes to deploy at least three helicopters for surveillance of the nearly 15,000 circuit km network, spreading over the National Capital Region, by December 23.
The company will hire a contractor who will hire two-seater helicopters, fitted with high-resolution and thermo vision cameras, and recruit pilots. PGCIL will pay the contractor for every km covered.
Finding suitable pilots is a major challenge, Sasmal said. They ought to be skilled enough to fly at very low altitudes, so that the cameras can keep tracking the transmission lines.
A PGCIL engineer will accompany the pilot to help map the transmission line. Once the helicopter returns to base, the company will scrutinise the images to identify sections that need a repair.
"If the project is successful we will expand the scope of air-surveillance to another 50,000 circuit km network," Sasmal said.
To further the scope of new-age surveillance systems, the company has also started GIS (geographic information system) mapping of its network.
"Our transmission network has grown 4.5 times since 1992. With a Rs 1,00,000-crore capital expenditure outlay for the Twelfth Plan (20012-17) period, the network is set to expand further.
"Naturally, the age-old systems were proving inadequate to keep a watchful eye on the health of such a vast electricity transmission network," Sasmal said.
As part of its automation programme, PGCIL will also start phasing out manually operated substations, beginning this month. In the new scheme of things, the substations will be fitted with CCTVs and remotely controlled from a distant base, using the IT backbone.
The company will have maintenance staff at designated locations to respond to any emergency. "We are now strengthening our fibre-optic network connecting the substations. This is to ensure adequate redundancy in the communication link.
"In the next six months 50-60 sub-stations in the northern region will be remotely controlled from Manesar in Haryana," said Sasmal. The project is expected to cover all the company's substations in one-and-a-half years.