The Spanish Grid Drop-out - recently released information.

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."
--
Bill Sloman, Sydney