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Europe: close to power grid blackout (49,74Hz power line frequency)

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Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#32
post #2

As someone who doesn't speak German and has only a cursory understanding of the electrical grid - how significant is this?

In general, slowing frequency is an indicator of a heavily loaded grid. I don't have an appreciation how much the frequency can practically be off the nominal 50 Hz (in Europe) before it indicates grid failure.

In practice it depends a lot on how a bunch of specific power equipment is set up.

Remember that the A/C power grid needs to be synchronized across the entire continent, so each A/C generator that makes A/C power and runs at 50Hz needs to have the position of a physical object (the rotors) match the position in the current power cycle. If it's badly wrong, you have power-plant sized energy feeds fighting each other — imagine a train wreck, two massive oversized freight trains smashing right into each other. It's like that, but with electricity instead of a physical collision.

This can obviously cause major damage, so once you start deviating from the reference frequency by enough, it's safer to just cut off the interconnects and go offline.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#33
post #29

Am I naive in assuming that many grid stability issues could be fixed by mandating all electric heaters automatically cut off at, say below 49.9Hz? It is my understanding that modern home EV chargers have the capability to do this to some extent, but I'm not sure if it's actually utilised?

It seems like a better solution would be batteries and/or the allowance of dirtier power generation (in emergencies). I can't even wrap my head around the regulatory nightmare of shutting off everyone's heat at night in January.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#34
post #29

Am I naive in assuming that many grid stability issues could be fixed by mandating all electric heaters automatically cut off at, say below 49.9Hz? It is my understanding that modern home EV chargers have the capability to do this to some extent, but I'm not sure if it's actually utilised?

I'm not sure that cutting off people's heat in the middle of winter is the most politically viable option.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#35
post #13

Earlier quoted context omitted.

It could be that, too. But I'm at a loss trying to think of how that much load could be added so suddenly.

Maybe somebody connected woodpecker [1] to the European grid? But I guess even that does not need enough power. [1] https://en.wikipedia.org/wiki/Duga_radar

Wikipedia says that's 10MW

The drop was around ~4.5GW

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#36
post #14

Romanian news are screaming about several counties (like 1/5 of RO) being blacked out and this being a problem at the interconnection with the neighboring power grids. From the little I know about power lines, events like this can cascade to half a continent.

High voltage fluctuations today. Instead of 220V we got down to ~165V. Internet outages on top (I assume some hardware failed since multiple counties were affected on the RDS network). Edit. Here's a power graphic: https://www.transelectrica.ro/widget/web/tel/sen-grafic/-/SE... Seems Romanias production fell under the consumption at around 15:30 Water fell at that time, so maybe some hydro was shut down? We did have…

> Seems Romanias production fell under the consumption at around 15:30

But the incident started at 15:05, that was just a consequence of interconnects failing i think.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#37
post #29

Am I naive in assuming that many grid stability issues could be fixed by mandating all electric heaters automatically cut off at, say below 49.9Hz? It is my understanding that modern home EV chargers have the capability to do this to some extent, but I'm not sure if it's actually utilised?

Most grids have a rapid response system like this. They’ll have contracts with very large power consumers (think big hydro pumps, metal smelters etc) that can afford to have their equipment power down without notice in exchange for energy rebates.

Then when the frequency drops these consumers will automatically turn off their equipment to reduce power draw.

The seeing such a huge drop like this is extremely unusual, no doubt many systems immediately started load shedding (both voluntary and involuntary) to compensate

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#38
post #29

Am I naive in assuming that many grid stability issues could be fixed by mandating all electric heaters automatically cut off at, say below 49.9Hz? It is my understanding that modern home EV chargers have the capability to do this to some extent, but I'm not sure if it's actually utilised?

I'm not sure that cutting off people's heat in the middle of winter is the most politically viable option.

It’s tends to be very viable. Most places can afford for heat to be shut off for 10-15mins without issue (think water heaters and whole building heaters).

That then gives the grid some time to spool up reserves. After all having your hear turn off for 10mins is better than having everything turn off for an hour, which could happen if the grid needs to shed load involuntarily.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#39
post #29

Am I naive in assuming that many grid stability issues could be fixed by mandating all electric heaters automatically cut off at, say below 49.9Hz? It is my understanding that modern home EV chargers have the capability to do this to some extent, but I'm not sure if it's actually utilised?

It seems like a better solution would be batteries and/or the allowance of dirtier power generation (in emergencies). I can't even wrap my head around the regulatory nightmare of shutting off everyone's heat at night in January.

Batteries maybe. Allowing "dirtier" non-50Hz power would make things worse, power plant turbines are optimized for 50Hz, different frequencies get inefficient quite fast. So your generation will shrink the lower you go. At the same time generators running at different frequencies will work against each other. At the same time machines will pull the frequency down even further, landing you in a vicious circle that forces the frequency toward 0Hz. No choice but to cut power before you damage too much of the grid and equipment.

Re: Europe: close to power grid blackout (49,74Hz power line frequency)

#40

Earlier quoted context omitted.

In general, slowing frequency is an indicator of a heavily loaded grid. I don't have an appreciation how much the frequency can practically be off the nominal 50 Hz (in Europe) before it indicates grid failure.

This is fascinating to me. What is the mechanism by which this happens? The added load causes an average slow down across the population of actual spinning generator bits?

Most power generators are rotating engines (there are exceptions like solar and and batteries that use power inverters).

Increasing load decreases frequency exactly the same way as anything rotating slows down when you increase load. Electric grid is like chain in a bike. Generator producing power leads a little. Loads follow little behind. They are not exactly matched. Like bike chain is tighter to one direction and looser to other under load.

Mass of rotating generators provide kinetic inertia into the grid so it reacts very little to small variations in the load. But if the load becomes too high and turbines can't speed up, frequency of the grid slows down.

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