An equipment failure in the protection system of a power plant in Ceará caused an overload that generated the energy blackout registered on the last 15th in 25 states and in the Federal District. The information was released this Tuesday (29) by the general director of the National Electric System Operator (ONS), Luiz Carlos Ciocchi, at the Chamber of Deputies.
Ciocchi participated in the joint meeting of the Chamber’s Mines and Energy and Financial Inspection and Control commissions. According to him, investigations into the case are ongoing and have the support of companies in the sector. It was confirmed that the whole problem began with the disconnection of a transmission line between the capital Fortaleza and Quixadá, in the interior of Ceará.
The director explained that technicians from the ONS (which is a private entity) received “clues” that the equipment of a plant would have taken a long time to come into action and only then were they able to have more clarity on what caused the failure, which reached about 30 millions of people.
According to Ciocchi, it was found that the equipment in question took between 80 and 100 milliseconds to react to the one-off drop – a much longer time than the expected 15 milliseconds. This overloaded the system and caused a series of other problems that, together, led to a general decline. A consolidated report, with details about the case, will be released in the coming weeks.
“Repeating what we said at the time (of the incident), this was not the cause of the phenomenon, as the Brazilian system has its redundancies (sequence protections) and is designed to withstand a simple loss of this nature”, he assured the deputies.
Still according to Ciocchi, the episode forced the ONS to reduce the volume of energy in the National Interconnected System grid as a precaution until the causes were fully investigated. Roraima, which is not connected to the system, was the only unaffected state.
*With information from Agência Brasil.
Editing: Geisa Marques
