Re: Grand Apagon - Electricity (not) in Spain

In message <vuqgef$1of93$1@dont-email.me>, Martin Brown <'''newspam'''@nonad.co.uk> writes

Spain suffered a very spectacular near total loss of its national grid yesterday taking parts of France and all of Portugal down with it. This is an unprecedented failure of a supergrid system by cascade failure.
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It seems likely they had got the effect of widespread solar PV has on load shedding wrong (much like happened in the UK) and so it failed completely. Two events a second apart delivered the coup de grace.
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They seem to have ruled out cyber attack and the electricity company is now trying to blame "the wrong sort of temperature variations"...
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Their 400kV lines seemed to be taking the blame with the national power company blaming exceedingly rare atmospheric phenomena due to "large" temperature differences in central Spain. They claimed that the magical sounding "induced atmospheric vibration" was to blame.
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https://www.theguardian.com/business/2025/apr/28/spain-and-portugal-powe
r-outage-cause-cyber-attack-electricity
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Another marginally plausible explanation given was that different impedances on cables at radically different temperatures on different paths messed up the phasing (but the numbers don't look right to me).
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Anyone have any idea what actually happened?
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The only one I am aware of that can take 400kV supergrid down is cables clashing together in older pylon configs where they are exactly one above the other and resonance effects allowing large amplitude standing waves to build up in the spans can occur in 70+mph winds.
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Most UK ones now have a longer central pylon spur so that the lines are more widely separated and up-down motion cannot allow them to touch.
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They do sing quite impressively in a gale though. The little weights at each end are apparently there to prevent such standing wave resonances damaging the pylon structure. Without them some pylons did fall down in the distant past during the most extreme of winter storms.
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You can wind back the Spanish Gridwatch to when it went TU and see what was happening up to the event. France and Portugal both vanish ,
https://demanda.ree.es/visiona/peninsula/demandaau/total/2025-04-28
Brian
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Brian Howie