European electric networks have undergone two oscillations half an hour before the total blackout in Spain
The European network of managers of the electrical transport network (ETSO-E) advanced on Friday that the blackout of April 28 was due to a “complex sequence of events” and which were recorded Two periods of voltage oscillations and frequency in electrical systems during half an hour before the accident.
The association, head of the independent European survey on the accident, reported in a declaration that in the hour before the blackout, which took place at 12:33, two oscillations were recorded in terms of power and frequency between the 12:03 and 12:07 and between 12:19 and 12:21.
“The managers of the transport network (electric) and France (RTE) took measures for Mitigate these oscillations. At the time of the accident, there were no oscillations and the variables of the electrical system were part of the normal operating interval, “explained Ento-E, who discovered that Spain was exporting 1,000 megawatt to then 1,000 MW) in France, 2,000 MW in Portugal and 800 MW in Morocco.
The agency indicated that the event began at 12:32:57 which, in 20 seconds, a “Series of different generations of travel” In southern Spain for about 2,200 MW.
“In Portugal and France, no generation trips have been observed. As a consequence of these accidents, The frequency has decreased And there is an increase in tension in Spain and Portugal “, it collects in this preliminary relationship.
Already between 12:33:18 am and 12:33:21, the frequency in the peninsula continued to fall to 48 Hercesos, who activated the emergency plans of both Spain and Portugal. In turn, alternating the current networks between France and Spain They successfully disconnected before the loss of synchronicity.
So, at 12:33:24 the “Full collapse of the Iberian electrical system” And also the high voltage cables between France and Spain have stopped transmitting energy.
Network restoration
Ento-E stressed that at 12:44, a first 400 kV line between west of Spain and France was reactivated again and that, 20 minutes later, the interconnection between Morocco and Spain were already operational.
From the beginning of the restoration to about 13.30, several Spanish hydroelectric plants have been launched with “black starting capacity” to start the restoration of the system. At 13:35, the connection in The eastern side of the Franco-Spanish border was active again.
In addition, at 16:11 and 17:26 Spanish peninsular time, the two electrical plants of Portugal with the black start capacity managed to restart after the “Previous attempts without success.”
So, the first 220 kV line between Spain and Portugal received energy at 18:36, accelerating the restoration of the Portuguese system. Also, at 9:35 pm, it was the turn of 400 kV connection which exists in the south of both countries.
Finally, the total recovery of the transmission system It was completed in Portugal at 00:22 hours April 29 and Spain around 04:00 on the same day.
The Ministry considers it “good news”
For its part, the Ministry for ecological transition and demographic challenge He considered a “good news” that has advanced in the analysis of the causes of the blackout and which have been provided initial estimates of the generation losses. In addition, “he greeted” the designation of the group of experts who will direct the independent investigations of Ento-E.
“Entonso and there is the transfer The causes of the crisis are complex And informs two periods of voltage and frequency oscillations in European electrical systems during half an hour before the accident, which stabilize the TSO of Spain and France “, have indicated sources of the Ministry.
In the same way, the department led by Sara Aagesen He reported that the Committee for the analysis of the crisis, whose work groups will continue to work this weekend, will meet again next Monday.
“The Committee will analyze all available elements e will continue to work with all operators To know with certainty the origin of the accident, “they added.
