The Transmission Company of Nigeria (TCN), says power supply was restored to areas that had been affected by the arcing on Benin-Egbin 330kV isolator which caused lines tripping and consequent loss of supply to some areas.
However, contrary to media reports, the incident did not cause system collapse.
The lines tripping started earlier at about 2:47 p.m. yesterday, with a heavy system surge that led to the arcing of Benin – Egbin 330kV line isolator fingers at Egbin Transmission Substation switchyard.
This resulted in a tripping at the Egbin Generating Station, which caused the loss of power supply to all the Egbin Transmission Substations’ outgoing lines.
This led to exponential increase in load on the Osogbo-Ihovbor 330kV line 1 with serious arcing of isolators terminals on the Osogbo-Ihovbor 330kV line 1.
To ensure that the sequence of events does not affect the nations’ grid, the Osogbo – Ihovbor 330kV line was opened to temporarily cut off the flow of electricity on that line.
At about 2:56pm, however, the Benin-Egbin 330kV line 1 Circuit Breaker also tripped at the Benin Transmission Substation end and this resulted in the loss of supply to Lagos axis, parts of the South West Region, parts of the North Central and Abuja.
Meanwhile, other areas, including the South Eastern region, North East, and other parts of North Central and South West, had full power supply.
The lines tripping was quickly rectified, enabling the grid controller to restore full bulk power supply through the transmission lines at about 6.10pm yesterday.
