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Failed to connect to MySQL: (1203) User howardkn already has more than 'max_user_connections' active connectionsPath: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: The Spanish Grid Drop-out - recently released information. Date: Sun, 11 May 2025 16:29:30 +1000 Organization: A noiseless patient Spider Lines: 82 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 11 May 2025 08:29:31 +0200 (CEST) Injection-Info: dont-email.me; posting-host="52959bd639cb7711fced2f7d5f8f858b"; logging-data="49439"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18aJGchiKUSjaq7h8TPZJMSVG3RFzuM+iU=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:xK1gYezNyP10Ix1XNeDgH459OJU= X-Antivirus: Norton (VPS 250511-0, 11/5/2025), Outbound message X-Antivirus-Status: Clean In-Reply-To: Content-Language: en-US Bytes: 4702 On 11/05/2025 4:58 am, john larkin wrote: > On Sun, 11 May 2025 02:46:34 +1000, Bill Sloman > wrote: > >> One of my LinkedIn contacts - an IEEE contact in this case - posted some >> new data on LinkedIn, from a "Simon Gallagher, Managing Director at UK >> Networks Services | CEng | FIET | FEI | MBA " >> >> "We have had an update from ENTSO-E on the Spanish complete power >> failure. It is limited, but it helps to build the picture. I have >> updated our charts with the new information. >> >> Updated timeline: >> >> 1. Large generators in the South of Spain started to trip at 12:32:57 >> CET. Over a period of 20 seconds a total of 2.2GW was lost – this is >> well beyond largest infeed so not secured against >> >> 2. The frequency looks to have been contained by system reserves until >> what looks like a large trip at 12:33:16 >> >> 3. At this stage, the frequency falls at about 0.5 Hz/s for 4 seconds, >> until a rapid collapse starts >> >> 4. By 12:33:21 the frequency has crashed to 48 Hz. At this stage the AC >> interconnectors to France trip >> >> 5. Low Frequency Disconnect was activated, but looks to have had no >> effect because 3 seconds later the system has collapsed completely >> >> 6. At 12:33:24 the system has completely collapsed, 27 seconds after the >> first trip. >> >> Some key comments from me: >> - LFDD/UFLS seems to have had no impact on the fall of frequency, I >> suspect RoCoF relays were operating by this stage, showing how unstable >> the grid was >> >> - I suspect a lack of rotating mass did mean that there was not enough >> time for LFDD to have an impact >> >> - A large divergence of frequency opened up between Spain and France for >> about 5 seconds. This must have meant a very large phase angle and large >> power flows >> >> - The previous data that showed the frequency only dropping to 49 Hz >> must have been a result of local generators kicking in where the >> Gridradar devices were connected to the network (UPDATE this has now >> been confirmed by Gridrader, their sensor in Malaga was switched over to >> a UPS and then generator at 12:33:20.7, prior to the disconnection of >> the Iberian Peninsula and therefore missing some of the frequency drop)" >> >> I haven't cut and pasted all of it. This paragraph struck me as interesting. >> >> "While I think a lack of inertia had an impact here, that does not mean >> that the level of solar and wind was to blame - rather it is how it has >> been integrated - more grid forming inverters, more rotating mass is >> needed, I suspect." > > Any hints at the precipating cause? "1. Large generators in the South of Spain started to trip at 12:32:57 CET. Over a period of 20 seconds a total of 2.2GW was lost – this is well beyond largest infeed so not secured against." This is a pretty clear statement. It doesn't say anything about why the large generators - type unspecified - lost 2.2GW of generating capacity over a twenty second period, and I haven't seen anything any more specific anywhere. > Maybe some modest local event triggered a fundamentally unstable > system. Too modest to have been noticed. Power generation systems are quite busy - people are connecting any disconnecting stuff all the time - so it would have taken a rather improbable modest event, or collection of modest events to to trigger this hypothetical mode of instability. -- Bill Sloman, Sydney