5 ms·

Apparently a local grid overload near France and a cascading failure down the Spanish network, but radio and newspapers don’t agree on root cause. Of course the

by rcarmo 2y ago

Apparently a local grid overload near France and a cascading failure down the Spanish network, but radio and newspapers don’t agree on root cause. Of course there is a lot of noise. For instance, one reporter asked one of the government flunkies whether it could be a cyberattack and they turned his noncommittal “maybe, we don’t know” into “government says cyberattack may be ongoing”. Be careful of idiot reporters out there. Edit: I’m listening to another radio interview where they are outlining the plans to bring online Portuguese dams and thermal generators over the next few hours, progressively unplugging from the Spanish supply (fortunately we have enough of those, apparently). It should take 3-4 hours to get everything balanced with only national supplies, and they will restore power from North to South.

rpastuszak 2y ago
I was going to say something similar. I live in Portugal and I've heard a lot of panic/fear mongering, mainly from the techies in the co-working space I was working on and expats. (apologies for singling out these specific groups of people - my point is that it might be worth to put down news sources like xitter, and read AP/translated local Portuguese news)
- divan 2y ago
  "xitter" in Portugese would be pronounced as "shee-tehr", right?
  - amanaplanacanal 2y ago
    That's how some have been pronouncing it in English, too.
  - deleted 2y ago
    [deleted]
martinald 2y ago
Yes, something similar happened in the UK a while back. Full info here: https://www.ofgem.gov.uk/sites/default/files/docs/2020/01/9_august_2019_power_outage_report.pdf https://www.ofgem.gov.uk/sites/default/files/docs/2020/01/9_... Key points that started it were (you can see the chain of events in the doc): 2.4.1. At 16:52:33 on Friday 9 August 2019, a lightning strike caused a fault on the Eaton Socon – Wymondley 400kV line. This is not unusual and was rectified within 80 milliseconds (ms) 2.4.2. The fault affected the local distribution networks and approximately 150MW of distributed generation disconnected from the networks or ‘tripped off’ due to a safety mechanism known as vector shift protection 2.4.3. The voltage control system at the Hornsea 1 offshore wind farm did not respond to the impact of the fault on the transmission system as expected and became unstable. Hornsea 1 rapidly reduced its power generation or ‘deloaded’ from 799MW to 62MW (a reduction of 737MW).
- ethbr1 2y ago
  Curious question for someone familiar with power at grid-scale -- How granular is load shedding? And how is this measured / tracked? In my head, I'm thinking of generators/plants, connected by some number of lines, to some amount of load, where there are limited disconnection points on the lines. So how do grid operators know what amount of load will be cut if they disconnect point A123 (and the demand behind it) vs point B456? Is this done sort-of-blind? Or is there continual measurement? (e.g. there's XYZ MW of load behind A123 as of 2:36pm)
  - martinald 2y ago
    They don't really disconnect it like that in these circumstances (as in they choose what to disconnect). As far as I know generation plants will start disconnect when grid frequency is <49Hz or >51Hz (at least in the UK) automatically as it's all starting to go very wrong. This is what causes this huge cascade effect. Roughly speak less frequency means there is more demand than supply and the other way round for higher frequencies. This has changed a lot though, as even home batteries afaik will start discharging if they start noticing the frequency dropping to provide some support on generation. But if it's dropping too fast and too quickly it won't help. But yes they do have very granular info on all the HV sources and how much load is on them.
  - pxdm 2y ago
    I can speak for the GB case. Low Frequency Demand Disconnection (LFDD) occurs automatically and in stages when the frequency drops until it stabilises. The substations or feeders that are tripped off are not currently determined by real-time metering - instead they are pre-allocated based on their typical demand. This means that the system operator does not really know how much demand will be disconnected at any given time. If it's sunny, you could easily trip off a lot of solar generation connected on the low voltage network, causing the frequency to drop further. It is far from optimal!
    - pbmonster 2y ago
      > The substations or feeders that are tripped off are not currently determined by real-time metering - instead they are pre-allocated based on their typical demand. This means that the system operator does not really know how much demand will be disconnected at any given time. This is wild. From a amateur technical perspective, it would only take a cheap hall sensor inside the transformer to have a pretty good guess of how much current has been flowing to the load. Hell, put the hall sensor onto a board with a micro controller and a LORA transmitter and stick it to the outside of the feed line. Seems like an incredibly cheap upgrade to get real-time load data from every substation.
aaron695 2y ago
[dead]
dark-star 2y ago
I can only imagine the "fun" in getting those synced back up to the European grid once this is all over... That alone will take weeks
HexPhantom 2y ago
It's a good reminder how much noise and misreporting flies around during live incidents

by rcarmo 2y ago

rpastuszak 2y ago

I was going to say something similar. I live in Portugal and I've heard a lot of panic/fear mongering, mainly from the techies in the co-working space I was working on and expats. (apologies for singling out these specific groups of people - my point is that it might be worth to put down news sources like xitter, and read AP/translated local Portuguese news)

divan 2y ago
"xitter" in Portugese would be pronounced as "shee-tehr", right?
- amanaplanacanal 2y ago
  That's how some have been pronouncing it in English, too.
- deleted 2y ago
  [deleted]

martinald 2y ago

Yes, something similar happened in the UK a while back. Full info here: https://www.ofgem.gov.uk/sites/default/files/docs/2020/01/9_august_2019_power_outage_report.pdf https://www.ofgem.gov.uk/sites/default/files/docs/2020/01/9_... Key points that started it were (you can see the chain of events in the doc): 2.4.1. At 16:52:33 on Friday 9 August 2019, a lightning strike caused a fault on the Eaton Socon – Wymondley 400kV line. This is not unusual and was rectified within 80 milliseconds (ms) 2.4.2. The fault affected the local distribution networks and approximately 150MW of distributed generation disconnected from the networks or ‘tripped off’ due to a safety mechanism known as vector shift protection 2.4.3. The voltage control system at the Hornsea 1 offshore wind farm did not respond to the impact of the fault on the transmission system as expected and became unstable. Hornsea 1 rapidly reduced its power generation or ‘deloaded’ from 799MW to 62MW (a reduction of 737MW).

ethbr1 2y ago
Curious question for someone familiar with power at grid-scale -- How granular is load shedding? And how is this measured / tracked? In my head, I'm thinking of generators/plants, connected by some number of lines, to some amount of load, where there are limited disconnection points on the lines. So how do grid operators know what amount of load will be cut if they disconnect point A123 (and the demand behind it) vs point B456? Is this done sort-of-blind? Or is there continual measurement? (e.g. there's XYZ MW of load behind A123 as of 2:36pm)
- martinald 2y ago
  They don't really disconnect it like that in these circumstances (as in they choose what to disconnect). As far as I know generation plants will start disconnect when grid frequency is <49Hz or >51Hz (at least in the UK) automatically as it's all starting to go very wrong. This is what causes this huge cascade effect. Roughly speak less frequency means there is more demand than supply and the other way round for higher frequencies. This has changed a lot though, as even home batteries afaik will start discharging if they start noticing the frequency dropping to provide some support on generation. But if it's dropping too fast and too quickly it won't help. But yes they do have very granular info on all the HV sources and how much load is on them.
- pxdm 2y ago
  I can speak for the GB case. Low Frequency Demand Disconnection (LFDD) occurs automatically and in stages when the frequency drops until it stabilises. The substations or feeders that are tripped off are not currently determined by real-time metering - instead they are pre-allocated based on their typical demand. This means that the system operator does not really know how much demand will be disconnected at any given time. If it's sunny, you could easily trip off a lot of solar generation connected on the low voltage network, causing the frequency to drop further. It is far from optimal!
  - pbmonster 2y ago
    > The substations or feeders that are tripped off are not currently determined by real-time metering - instead they are pre-allocated based on their typical demand. This means that the system operator does not really know how much demand will be disconnected at any given time. This is wild. From a amateur technical perspective, it would only take a cheap hall sensor inside the transformer to have a pretty good guess of how much current has been flowing to the load. Hell, put the hall sensor onto a board with a micro controller and a LORA transmitter and stick it to the outside of the feed line. Seems like an incredibly cheap upgrade to get real-time load data from every substation.

aaron695 2y ago

[dead]

dark-star 2y ago

I can only imagine the "fun" in getting those synced back up to the European grid once this is all over... That alone will take weeks

HexPhantom 2y ago

It's a good reminder how much noise and misreporting flies around during live incidents