BUENOS AIRES – An operating error by high-voltage power transportation company Transener was the main cause of the total blackout affecting Argentina, Uruguay and parts of Paraguay on June 16, Argentina’s energy secretary said in a Senate hearing on Wednesday.
“They needed to reprogram it (the Automatic Disconnection of Generation, DAG) and they didn’t do it. Transener has recognized this operating error in their reports,” Gustavo Lopetegui told a group of ruling-party and opposition senators.
In an initial official appearance to comment on the preliminary findings of the investigation, Lopetegui said the DAG problem triggered the blackout but that several other circumstances were involved and that regional power generators and distributors also shared some of the responsibility.
He said that at 7.06 am that Sunday, a time of generally low electricity demand, a short circuit occurred on one of the two high-voltage transmission lines running between Colonia Elia, in the northeastern province of Entre Rios, and Campana, in Buenos Aires province.
Buenos Aires province is the destination for a large amount of energy from the northern part of the country, where the Yacyreta and Salto Grande hydroelectric dams are located.
The other transmission line on that same route had been temporarily out of service since April 18 because Transener had to relocate a tower, although the company had built a bypass to ensure there would be no disruptions to supply.
“Short circuits occur all the time, in Argentine around 60 times a year. It’s a habitual event, but that doesn’t mean it has to cause what it caused later, because that’s what the protection mechanisms are for and that’s why we have redundancies so electricity can be sent via other routes if one of the routes is disabled,” Lopetegui said.
Lopetegui said that after the short circuit occurred the DAG should have functioned, since that problem meant that all the energy demand coming from the south exited the system.
“To compensate for the absence of that demand, the DAG would have automatically had to send a signal to the north to say ‘partially lower’ (the potency). And that signal didn’t exist because when Transener built the bypass and changed the architecture of the network it needed to have reprogrammed the parameters of the DAG, which continued to think there were two lines feeding it,” he explained.
“And due to an operating omission by the Transener company, because it did not adhere to the protocol established for reprogramming the DAG when the topology of the network changed, that DAG didn’t fire. The company has recognized that. There’s no doubt they made the evaluation that there was no need to reprogram the DAG, and in fact there was a need to do so,” Lopetegui said.