Northern Grid had close shave a day before collapse
POSOCO said that a "similar incident at 1510 hours on July 29 had also led to a near miss situation."
New Delhi: Hours before a Northern Grid failure pushed a major part of the country into darkness early morning on July 30, electricity transmission lines witnessed a "near miss situation" due to power overdrawals in parts of Uttar Pradesh and Madhya Pradesh, an internal probe has found.
The Northern Grid, which serves more than 30 crore people across nine regions including the National Capital, had first tripped on July 30 at 0233 hours and then again on July 31 at around 1300 hours.
However, an initial investigation into the matter by PowerGrid subsidiary Power Systems Operation Co Ltd (P0SOCO) has found that a prior incident of heavy power flow had led to "a near miss situation" at 1510 hours on July 29 as well.
In the first failure on July 30, "nearly the entire Northern Grid was affected while in the second disturbance (next day), the Northern, Eastern and North Eastern grids were affected to a large extent," POSOCO has said in its initial report on this power crisis.
"In both the disturbances, in the antecedent grid conditions there was heavy power flow on the 400 kV Bina- Gwalior-Agra single circuit section crossing 1000 MW on the single circuit available," it said.
While Bina and Gwalior are in Madhya Pradesh, Agra is part of neighbouring state, Uttar Pradesh.
Another circuit on this corridor was already "under outage since July 28 for upgradation to 765 kV level," it added.
POSOCO further said that a "similar incident at 1510 hours on July 29 had also led to a near miss situation."
The report said this particular section was taking a load much higher than its limit, while loading on many circuits in the Eastern region was over and above the normal levels.