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European Blackout - January 8th 2021

AncientMariner
Forgive me if this posted elsewhere here, but just came across the following on a Time Dissemination forum I frequent from a German poster.

On Jan.8, 13:04:54 UTC, the european grid frequency dropped from 50.0269Hz to a minimum of 49.7343Hz 13.4sec later, see fig 1 below, plot starting at 13:00, x-axis in sec. .

As a result southeast Europe was split from the rest, the frontier crossing the Balkan countries, see
https://www.entsoe.eu/news/2021/01/15/system-separation-in-the-continental-europe-synchronous-area-on-8-january-2021-update/

At 13:42:35 the western frequency was back at the 50Hz level, some time later they managed to resync the east and reconnected. Reasons are still under examination. A high western demand faced a southeastern production, so after the split the western frequency went down, the eastern frequency went up.

At 79/50 sec. after the event the primary control kicked in at 49.9035Hz and brought it up again to 49.9308 but eventually failed, see fig   2. below.

In the 13. hour that day they failed to deliver 112 sinewaves. Now ENTSO-E has to decide: readjust the wall clocks in Berlin or Athens?   )

Reportedly at a frequency below 49.8Hz big loads, like pumps for reservoirs or industrial customers are switched off automatically.

In 2011 the German Government launched a scenario for a blackout, detailed as a script:
https://www.tab-beim-bundestag.de/en/publications/books/petermann-etal-2011-141.html


Clive
f78d55e118b9b0d15fb9e7890397a312-huge-fig1.pngc
780060cda814b163f7e49f3827bd2f76-huge-fig2.png
  • 0
    I wonder why they worry so much about such a small frequency deviation ? Our grid varies more than that without problems.

    49.73 cycles is well within the UK legal limit of from 49.5 cycles up 50.5 cycles.

    The UK National grid try to keep the frequency within closer operational limits of 49.8 cycles to 50.2 cycles, however excursions outside these operational limits occur fairly regularly without significant consequences AFAIK.
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    C.C.G.T. is working hard for us at present.

    GB Fuel type power generation production (gridwatch.co.uk)


    Z>
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    In August 2019 there was a large power cut across south east England, some electric powered trains were still running in unaffected areas, but did cut out automatically, as the Frequency had dropped, iirc, to just above 49Hz.

    An inquiry afterwards confirmed that they should not have stopped at the frequency the did cut out at, as the Rail Standards Board specify a frequency that they should run at, and it went below 49Hz. I cant find the full report now, but did read it when it was published. What did cause the real problems was that the train software would not restart the trains once a decent frequency had been restored, causing widespread rail transport problems.

    One report, not focusing on the rails:
    https://ukerc.ac.uk/news/what-happened-electricity-system-fri-aug-9-2019/

  • 0
    broadgage:

    I wonder why they worry so much about such a small frequency deviation ? Our grid varies more than that without problems. . . 


    I suspect that the issue here is that the European Grid split into two pieces, for reasons that are currently unknown, and with the entertainment of trying to synchronise two large power systems, with the issues of coordination that requires. A lot of equipment still uses the mains frequency for timing, as it is a cheap and accurate method. With being split into two, “Power System Time” will be different by a few seconds between the bits. I wonder how the agreements in place between the various countries will allow this to be resolved. One possibility would be to declare the Power System Time to be equal to GPS time at a certain date and time in the future. 


    Regards,


    Alan. 


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    Interesting, links, thanks, it reads rather as if the separation was automatic in response to an 'off frequency' condition. I am wondering if the reason is actually the large currents that flow between zones trying to run at different speeds, where the offset translates to a large out of phase power flow, rather than the change in frequency itself. (or at least things need to be set 'twitchy' because of this.)

    One of the issues with replacing traditional large spinning generators with lots of inertia with non-inertial  things like solar panels with inverters, is that the link between overload and frequency is weakened, and automatic systems that use the frequency to decide when to disconnect are likely to be more easily confused, It is possible to program an inverter (well a non-commutating type) to mimic the frequency falling under load, but the dynamics are not really the same.


    Anyone interested in the UK mains frequency may find  This UK mains measuring site interesting.

    And the fact that the jumpy nature f it can be  used to date audio recordings,  (see here)much like tree rings in ships timbers can be matched to  the weather records or a particular century to date them.

    M.
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    Thanks - I'd heard of the split, but not thought of the implication of whose mains-operated clocks will be made right afterwards. Some authors from EDF argued well in 2009 against continuing to use the power system to cater for people's clocks ( here:  "Five good reasons to abandon synchronous time control", Rebours et al).  Unfortunately I don't see a full version publicly available, though the Abstract gives some clue of the content.  But it sounds as if the continental system still strives for this timing. The split looked very non-central - in other words, it would surprise me if the bigger region (north/west) isn't the one whose time ends up right, if someone's has to.
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    In terms of consumer's time-keeping equipment isn't a few missing cycles inconsequential compared to an actual power cut? Presumably they must have a mechanism to cope with power cuts (e.g. manually reset the clocks) - so just treat it as if there had been a short outage?

       - Andy.
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    So, is the time in the UK still in sync with Western Europe?
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    A couple of years ago I was involved in wiring a new house out in Herefordshire, there was another guy who was working with me who then got a job wiring up the bogeys to pull a new high voltage DC cable through the service tunnels of the Channel Tunnel.

    https://www.balfourbeatty.com/news/balfour-beatty-consortium-awarded-219-million-eleclink-contract-to-install-interconnector-through-channel-tunnel/


    I presume because the Channel Interconnectors are D.C. there is not any time reference on them, so UK time is not tied to European time through the HVDC interconnectors?
  • 0
    The bogeys were actually being made up in Hereford.

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