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The worst blackout in recent history occurred in northern India on two consecutive days in__________
30-31 July, 2012
25-26 June, 2013
20-21 March, 2009
None of above
30-31 July, 2012
Quick Summary: The 2012 India blackout was the largest power outage in history, affecting over 620 million people. It occurred in two phases on July 30 and July 31, 2012, due to severe cascading failures in the Northern, Eastern, and North-Eastern regional grids.
The 2012 India blackout was the largest power outage in history, affecting over 620 million people. It occurred in two phases on July 30 and July 31, 2012, due to severe cascading failures in the Northern, Eastern, and North-Eastern regional grids.
P=XV1V2sinδ — Power transfer equation indicating dependence on line reactance and voltage
f=2πLC1 — Resonant frequency relation governing grid stability harmonics
The collapse was caused by a combination of high power demand, low hydro-power generation, and the outage of critical transmission lines (like the 400kV Bina-Gwalior line). This triggered a cascading effect where overloading led to relay trips, causing the grid frequency to deviate rapidly from the 50Hz nominal value, eventually leading to a total system collapse.
Affected 22 states in Northern, Eastern, and North-Eastern regions.
The collapse triggered the implementation of the 'Automatic Under-Frequency Load Shedding' (AUFLS) schemes.
Increased dependence on 'Power System Stabilizers' (PSS) for grid damping.
Led to the amendment of grid codes to prevent 'N-1' contingency violations.
Enhanced focus on grid security standards.
Upgradation of SCADA and Wide Area Measurement Systems (WAMS).
Massive economic disruption and loss in industrial production.
Risk of damage to sensitive electronic equipment due to voltage surges.
Load Dispatch Centers (LDC)
Transmission Grid Planning
The blackout highlighted the danger of 'weak links' in an interconnected synchronous grid.
Option B (2013) and Option C (2009) do not correspond to any grid collapse events of this magnitude.
A is correct — The 2012 India blackout was caused by cascading transmission failures on 30-31 July 2012.
In competitive exams, always remember that power system collapse is primarily a result of frequency instability leading to voltage collapse.