On April 28 at 12:33:30, an energy zero disconnected the electrical systems of Spain and Portugal from the rest of Europe. It was not a cyber attack, but a waterfall of surge and an insufficient control system, according to the Spanish government.
The analysis committee report. Minister Sara Aagesen has presented 49 days after the blackout (half of the term established by Brussels) the result of an analysis of more than 300 GB of information carried out by the Government Committee.
The complete document concludes that there was no unique cause, but a waterfall of failures that pushed the system beyond its limit, and mainly indicates Red Electric, who will answer on Wednesday by making their own report public.
The Government points to Red Electrica. During the morning of the incident, the system already showed an “atypical volatility” in tensions, according to the analysis. The situation worsened between 12:00 and 12:30, when the network suffered two major oscillations. The first, at 12:03, was an anomalous phenomenon of 0.6 Hz originated within the Peninsula.
The second, at 12:19, was a more common oscillation at European level of 0.2 Hz but of a three -time amplitude. To stabilize the system, Electric Red reduced energy exports and increased the network’s misery, actions that, ironically, raised more the general tension of the system.
A domino effect in 12 seconds. From 12:32, with the already tension network, the trigger occurred: a sequence of disconnections of large blocks of renewable generation. The report identifies three key events that started the catastrophe.
At 12:32:57 355 MW were disconnected in a substation of Granada. At 12:33:16, approximately 730 MW was lost in a collecting substation in Badajoz. At 12:33:17 another 550 MW fell into a substation in Seville. Each of these disconnections caused the system tension to rise a little more.
The more the tension rose, the more generators they disconnected to protect themselves, which in turn raised the tension, causing new disconnections. In just 12 seconds, the massive generation loss caused a frequency drop, which was a consequence, not the cause. At 12:33:19, the Iberian system lost synchronism with Europe and was completely disconnected.
Why the system fell. The underlying problem was a “insufficiency of dynamic control capabilities of tensions”, inability to manage surge, according to the committee. The report indicates that some of the first disconnections in Granada, Badajoz and Seville “would have occurred before the voltage thresholds established by the regulations”, one of the critical points of the collapse.
Another critical point was that the large thermal plants that should act as a brake of the voltage increases did not do it with the necessary force because the number of synchronous plants coupled for this function was the lowest of the year. To top it off, some of the centrals that were operating “did not respond properly.” Instead of absorbing reactive energy to lower the network pressure, they acted anomalously, even producing it, “the opposite of what is required, contributing to increase the problem.”
In the words of the Ministry for Ecological Transition, control resources were missing, “but not because they were missing in the country; there was a generation park rather than enough to respond.” Again, the committee points to the network operator.
The measures on the table. To prevent an event from these dimensions, the report proposes to strengthen supervision to guarantee compliance with the regulations, regulate the legal regime of evacuation infrastructure, implement in an “immediate and priority” way a new service that allows renewables to participate in voltage control, invest in new synchronous compensators and increase interconnection with France.
On the other hand, a cybersecurity investigation that, according to the Government, was “the largest in the history of Spain” with more than 75 experts, concluded that there was no cyber attack. However, deficiencies were identified, so the Committee recommends streamlining the application of European regulations, strengthening access controls and segmenting networks.
On the Electric Red Roof. After the tough coup of the government, it only remains that Red Eléctrica published on Wednesday its report as a system operator to have the other point of view. For now, the Committee will put its findings in the knowledge of the National Markets and Competition Commission to, in its case, open the corresponding administrative procedures, with all guarantees, and all its consequences. ” Technical research is over, now begins the search for responsibilities.
Imagin | Victor Romero (CC BY-NC-SA 2.0)
In WorldOfSoftware | A town of Granada of one thousand inhabitants with 700 MW of renewable energy: the place where the blackout began
