The Transmission Company of Nigeria (TCN) has stated that the system failure on Wednesday morning was caused by a tripped off turbine, which affected an entire Generation Company (GenCo), resulting in a 450 megawatt loss (MW).
TCN spokesperson Ndidi Mbah said in a statement on Thursday that despite initial setbacks, grid restoration was completed last night.
“As obtainable in all systems, when a component of the electric power system is defective, the entire configuration is vitiated.”
TCN said the system disturbance occurred at about 11.27am on Wednesday resulting in a sudden drop in system frequency from 49.94 Hertz (Hz) to 47.36Hz, which created system instability.
According to reports obtained from the TCN National Control Centre (NCC), the tripped unit at the GenCo was due to ‘Exhaust over Temperature’.
“This unwholesome event, which pulled out other grid-connected units in the plant, resulted in aggregated generation loss of 457MW. In its wake, a train of events ensued – culminating in the collapse of the national grid.
“Meanwhile, a full-scale investigation is being conducted to establish the cause of this failure,” TCN said.
Experts believe that if the grid has over 10,000MW active energy, the loss of 450MW may not significantly affect the system like on Wednesday when the grid had just 2,700MW by 11am, minutes before the system collapsed.