The European Network of Electricity Transmission System Operators (Entso-e) announced that, half an hour before the blackout that hit the Iberian Peninsula, there were “two periods of power and frequency fluctuations” in continental Europe.
In a statement, ENtso-e highlighted that these disturbances in the synchronous zone of continental Europe occurred at 12:03 and 12:07 (11:03 and 12:07 in Lisbon) and that both the Spanish Electricity Grid and the French RTE had taken measures to mitigate these fluctuations.
Entso-e also said that, at the time of the incident on the 28th of April, around 12:32 (11:32 in Lisbon), there were no oscillations and the variables of the electrical system were within the normal operating range.
Before the incident, Spain’s international exchange programs were 1,000 MW for France, 2,000 MW for Portugal, and 800 MW for Morocco, all intended for export.
The blackout, the agency recalled, left Spain and Portugal in a blackout situation, in addition to affecting an area of southern France, although the rest of Europe did not suffer any interruption, despite previous fluctuations.
It is believed that the sequence of events began at 12 hours, 32 minutes and 57 seconds, when, for twenty seconds, a series of different generation ‘trips’ were presumably recorded in the south of Spain, up to a total of 2,200 MW, while such leaks were not observed in Portugal and France.
As a consequence, the frequency decreased, and an increase in voltage was observed in Spain and Portugal. According to the sequence of events, during the following three seconds, the frequency of the Iberian Peninsula continued to decrease to 48 hertz. At this time, defence plans against automatic shutdown were activated.
At 12:33, the alternating current overhead lines between France and Spain were disconnected by desynchronized protective devices, and power transmission between France and Spain stopped immediately. As soon as the power outage occurred, the affected countries worked together to restore power.
Entso-e stressed that, after the blackout, a joint expert group was created with members of Entso-e, transmission operator systems, the Agency for the Cooperation of Energy Regulators and national and regional regulatory authorities.
The panel is led by experts not directly affected by the incident and includes experts from affected and unaffected regions. Its objective is to investigate the causes and make recommendations.
A generalised cut in the electricity supply affected Portugal and Spain, for approximately 10 to 11 hours, as well as part of France.
Reports show that airport closures, transport, and traffic congestion in large cities, and a lack of fuel were some of the consequences of the blackout.
Samantha Gannon
info at madeira-weekly.com
