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What Happened in the UK Blackouts?

mitchoneill.com

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Re: What Happened in the UK Blackouts?

#71

Post by trebligdivad »

Zenst wrote: post #30
mytailorisrich wrote: post #25

Earlier quoted context omitted.

It's clear that there were issues at hospitals (as expected cynical me thinks, knowing British healthcare...) but the fact that key infrastructure lost power does points to issues at the grid level as well (because sites that lost power did so based on grid procedures).

When they cut the power to an area, they can't selectively keep isolated locations active unless they are isolated in that they operate upon their own spur. That is why Hospitals would be deemed critical and important not to cut out, they are handled by onsight failover power supply in the form of backup generators. In this case, it was like asking somebody to be able to catch a ball, they say they are ready and yet…

The actual report says that Ipswich hospital wasn't part of the load shedding; so it's not clear why the generators had to cut in in the first place yet.

Re: What Happened in the UK Blackouts?

#72

Post by trebligdivad »

mitchoneill1 wrote: post #28
pm215 wrote: post #20

The article says near the bottom "At the time [the GT1A generator tripped] there was 4000MW of unused generation in reserve, and if only a fraction of this reserve was instructed to dispatch within 60 seconds of the initial loss it’s very likely that load shedding would have not occurred." My understanding was that having reserves available within 30-60s was pretty expensive, and that that would have been what was us…

Hey! (author of the article here). I'm not happy with how I phrased this with the 4GW of capacity -- and while I suspect generation could have increased by hundreds of MW within 60 seconds I may be wrong. I've updated how I've phrased it in the blog to hopefully give a bit more clarity to my position. I don't meant to suggest that plants could ramp full within 60 seconds, it's that 4GW means there's a bunch of headro…

I suspect it being evening peak made it worse, because that's peak time, so I think in normal operation they're discharging some of the batteries/pump storage that's taken up some of the spare capacity during the day. I would encourage more people to read the actual interim report - it's quite detailed with lots of detail about the frequency measurement and trips.

Re: What Happened in the UK Blackouts?

#73

Post by barney54 »

guerby wrote: post #47
mitchoneill1 wrote: post #28

Earlier quoted context omitted.

Hey! (author of the article here). I'm not happy with how I phrased this with the 4GW of capacity -- and while I suspect generation could have increased by hundreds of MW within 60 seconds I may be wrong. I've updated how I've phrased it in the blog to hopefully give a bit more clarity to my position. I don't meant to suggest that plants could ramp full within 60 seconds, it's that 4GW means there's a bunch of headro…

I assume battery based grid power stations like the Tesla one in Australia are amongst the best in class to help in this kind of crisis situation? Compared to the gaz turbine the system it is simpler (no mehanical/heat/fluid parts) and depending on design will likely never be completely off since made of dozens or hundreds of independant equipement (batteries and inverters). Thanks for the article and comment!

Yes, batteries are very fast acting, but that battery in South Australia is only 100MW and the grid lost over 1400 MW. https://www.news.com.au/technology/innovation/inventions/eve... Batteries have a lot of potential, but they are currently small in capacity.

Re: What Happened in the UK Blackouts?

#74

Post by [deleted] »

mytailorisrich wrote: post #6
Zenst wrote: post #2

"Frequency drops below 48.8Hz which triggers the Low Frequency Demand Disconnection scheme (LFDD). Approximately 1GW (5% of total) of Great Britain electricity demand is turned off." Is interesting as it highlights the importance of managed failure. Things fail, but the ability to see those failures and control how that fails is important. Had such an action not been taken, the result would of been a far greater outa…

The issue with this specific outage is that it was badly managed. The main gripe people and authorities have with what happened is that key infrastructures immediately lost power. When (only) 5% of demand is turned off this should not impact railways, airports, and hospitals. Beyond the initial loss of power other problems amplified the consequences: For example, trains could not just restart but required specialist…

[deleted]

Re: What Happened in the UK Blackouts?

#75

Post by danpalmer »

aurbano wrote: post #41

It actually sounds like this was really useful though, as a lot of the systems involved will be improved in the future. I'm not sure if the grid is already doing this, but they should trigger failures randomly, including Low Frequency Demand Disconnection schemes from time to time to ensure that all downstream systems are also ready (like the hospital someone mentioned that had an issue with the backup generator, or…

I assumed that the LFDD scheme was a small number of large power users such as factories that would get cheaper rates, much like AWS spot instances. Another commenter has said this is how it works in Germany.

Unfortunately, some quick research[1] suggests this isn’t the case, and actually it’s just a contractual obligation of the power companies to disconnect enough demand to bring power use back down. The amount they need to disconnect is banded by the frequency the grid is at, and apparently done at the substation level.

Some industries/applications such as infrastructure, hospitals, airports, etc, is supposed to be set up to never disconnect in these scenarios, but it seems this failed.

[1]: https://www.westernpower.co.uk/downloads/4093

Re: What Happened in the UK Blackouts?

#76

Post by KyleJ61782 »

std_throwaway wrote: post #63
londons_explore wrote: post #16

It's notable that this report is completely consistent so far with the way I would design a cyber attack to take out a countries power grid. > The causes provided by RWE for the initiation of the trip of Little Barford steam turbine (ST1C) was due to discrepancies on three independent safety critical speed measurement signals to the generator control system. A cyber attack would most likely, rather than directly take…

An even more stealth method is to make the system work perfectly if everything is running fine. Like correctly reporting net frequency in the range 49-51 Hz but reporting false values when outside of that range. That way there will be no detectable errors until everything starts behaving erratically. The best way for a society to prepare is to have a few small incidents that put the safety systems to the test on a re…

This. Very much this. In the presentations I've seen on the matter, the most vulnerable systems are those measuring and carrying telemetry back from various meters around the power system. One doesn't have to directly compromise the system to have an effect. Simply providing bad data to automated protection systems could be enough to cause instability.

Re: What Happened in the UK Blackouts?

#77

Post by guerby »

barney54 wrote: post #73
guerby wrote: post #47

Earlier quoted context omitted.

I assume battery based grid power stations like the Tesla one in Australia are amongst the best in class to help in this kind of crisis situation? Compared to the gaz turbine the system it is simpler (no mehanical/heat/fluid parts) and depending on design will likely never be completely off since made of dozens or hundreds of independant equipement (batteries and inverters). Thanks for the article and comment!

Yes, batteries are very fast acting, but that battery in South Australia is only 100MW and the grid lost over 1400 MW. https://www.news.com.au/technology/innovation/inventions/eve... Batteries have a lot of potential, but they are currently small in capacity.

According to the article it was a cascade of events and the last one was the 244MW gas turbine going out that lead to the collapse so not that far from current scale grid batteries.

Also battery reacting instantaneously to correct or mitigate a grid issue might avoid some other generator to go offline or allow to go offline for a must shorter amount of time avoiding some of the cascading effects.

It seems to me that the value of grid batteries is not just the nameplate capacity compared to other generation technologies, it is a class on its own.

May be once batteries are incorporated in the grid at some scale software triggers commanding other generators capacity disconnect/reconnect will have to be updated "let the grid batteries do their job first and then act".

Re: What Happened in the UK Blackouts?

#78

Post by KyleJ61782 »

mytailorisrich wrote: post #48
Zenst wrote: post #42

Earlier quoted context omitted.

"Would you not prioritise an airport, a hospital, the railway, over residential areas?" Yes and they do. As mentioned, things get added to the grid all the time, case of the airport was that it was not on a priority list. Yes that is an oversight, but who's fault and accountability we do not know. The onus would of been in the airport to inform the power distribution and if that failed to happen then the airport woul…

You protest a bit too much at this point, methinks. I am commenting that the scale of the disruption resulting from (only) a 5% drop does not seem reasonable and that some of the issues should have been better handled or avoided altogether. > But I and I'm sure many others would not be focusing upon that, though I can appreciate that mentality due to the way media/tabloids cover such and all issues in life That's a p…

> > But I and I'm sure many others would not be focusing upon that, though I can appreciate that mentality due to the way media/tabloids cover such and all issues in life

> That's a personal attack quite out of order.

Not really. It's just a societal commentary on how we've conditioned ourselves by the media we consume into passing quick blame instead of taking a slow, reasoned approach to analyzing the event, seeing the compounding factors at stake and only in the face of gross negligence assigning blame.

Re: What Happened in the UK Blackouts?

#79

Post by danw1979 »

HenryBemis wrote: post #66
londons_explore wrote: post #16

It's notable that this report is completely consistent so far with the way I would design a cyber attack to take out a countries power grid. > The causes provided by RWE for the initiation of the trip of Little Barford steam turbine (ST1C) was due to discrepancies on three independent safety critical speed measurement signals to the generator control system. A cyber attack would most likely, rather than directly take…

> A cyber attack would most likely.. When I was discussing the two interruptions (one on the 9nth and a smaller one on the 24th) with friends, I suggested that this could have been an attempt to map out UK's infrastructure/SCADAs, and they thought that my sandwich had too much consiracy sauce in it. Remembering how Stuxnet interefered with Iran's nuclear centrifuges, this could very well be something similar. Just sc…

It didn't sink itself though. There was no loss of the entire grid.

Re: What Happened in the UK Blackouts?

#80

Post by pedrocr »

radiowave wrote: post #44
pedrocr wrote: post #27

Isn't this kind of fault a good argument for synchronizing the UK grid to the rest of Europe? They seem to already have an interconnect that's of the scale of demand needed here, but it's a DC link.

If they were synchronized, it would mean that in the case of any larger failure that would draw too much current over the undersea link, the link itself would have to trip out.

That depends on the link size. But I guess it may very well be better to have a big enough DC link and have it automatically modulate power all the way up to maximum and then keep it there, instead of tripping.
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