Inter State Transmission System reliability concerns deepen as disturbances expose hidden grid weakness
Inter State Transmission System performance is under sharper scrutiny after a series of frequency events, voltage instability episodes, and project execution delays. The latest data shows a 0 percent peak deficit on paper, but that did not prevent frequency from falling to 49.62 Hz. This suggests that reported adequacy is not fully capturing operational stress developing within the network.
A key signal comes from the 16.5 GW load drop event. The disturbance involved HVDC tripping, renewable volatility, frequency spikes, voltage surges, and tripping of 18 EHV lines. At the same time, the northern grid continued to face persistent overvoltage even after shutdown interventions. Rajasthan renewable zones were also flagged for low system strength and oscillatory behaviour. These developments indicate that the Inter State Transmission System is facing both dynamic stability stress and reactive power management challenges.
The document also points to control and coordination gaps. SCADA failure at NTPC Gandhar reduced real-time visibility. Audit and funding delays are slowing protection upgrades in the North East. Communication outage proposals remain irregular. On the project front, Transmission infrastructure reports from the Central Electricity Authority show progress tracking, but also underline delays linked to bay readiness, approvals, and repeated outage extensions.For EnergylineIndia.com, this Inter State Transmission System update matters because it combines system operation risk with implementation bottlenecks. When frequency stress, voltage instability and delayed transmission works appear together, the Inter State Transmission System becomes more vulnerable to disruption than headline numbers suggest.












