Reactor fire may have caused blackout on the 14th, says ONS report

A preliminary analysis of the blackout that occurred on October 14 reports that a fire in the reactor line of the 500kV Ibiúnas - Bateias transmission line was the starting point of the incident. The report with the cause of the blackout was released by the National Electric System Operator (ONS) on Friday night (17). The reactor that caught fire is owned by Eletrobras.

The fire caused the system's protection to shut down the circuit, which was expected, but it also led to the incorrect shutdown of the transmission line's C1 circuit. The problem extended to the busbar at Copel's Bateias Substation. The busbar's protection should have contained the problem, but it didn't, resulting in multiple shutdowns of the transmission lines connected to the substation, also leading to the shutdowns of the 500kV Londrina–Assis transmission line and the 765kV Ivaiporã–Itaberá–Tijuco Preto transmission line.

According to the ONS report, the outages led to the disconnection of the Southern region's electrical system from the rest of Brazil. Since the Southern region exported approximately 5,000 MW to the rest of the National Interconnected System, there was a frequency increase in the Southern subsystem and a frequency reduction in the other subsystems. The problem began at 12:31 AM, with load restoration beginning at 12:35 AM and ending at 2:15 AM.

ONS agents will hold a new meeting on the 28th to continue preparing the Disturbance Analysis Report. Once completed, it will be forwarded to all involved agents for compliance with the document's provisions, as well as to ANEEL and the Ministry of Mines and Energy.

The full report on the blackout was published on the ONS website.