8 ms·

What Is "Induced Atmospheric Vibration"?

167 points by belter 2y ago

belter 2y ago
"Diagnosis and Mitigation of Observed Oscillations in IBR-Dominant Power Systems - A PRACTICAL GUIDE" - https://www.esig.energy/wp-content/uploads/2024/10/esig-rpt-oscillations-8.24-print1.pdf https://www.esig.energy/wp-content/uploads/2024/10/esig-rpt-...
juancn 2y ago
"Real electrical systems have to deal with issues of reactance and other exciting math-heavy constructs designed to drive you into some other field of study." They had me at this
- SoftTalker 2y ago
  Wonder how much complexity using AC adds to this? With DC you would not have to worry about frequency and phase matching. But then you need to convert the DC back to AC at some point.
  - deleted 2y ago
    [deleted]
  - Cthulhu_ 2y ago
    Some parts of the energy transmission grid are DC, but looks like it's mainly international, undersea, and long-range transmissions: https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current
    - sam_lowry_ 2y ago
      And only because long-distance transmission is more efficient.
  - raverbashing 2y ago
    > Wonder how much complexity using AC adds to this? Summarizing a couple of year of very annoying electrical studies: Yes You can't believe how much
    - formerly_proven 2y ago
      On the other hand, having a continent-scale AC grid is not just possible but common. Europe and North Africa have one, Russia has one, China has one, the US has two or three. Meanwhile multiterminal HVDC is basically experimental stuff that's only possible with real-time digital control systems.
      - raverbashing 2y ago
        Having a worldwide data network is also only possible with real-time digital control systems as well The issue is one of technology (having high powered switching components only took of in the last 30? yrs or something) and legacy (Edit: IGBTs are from the 80's though it seems the 1st generation wasn't that great, IGCTs from the late 90s https://mb-drive-services.com/experience-with-igct-based-vfd/ https://mb-drive-services.com/experience-with-igct-based-vfd...
  - lazide 2y ago
    (Efficient) High voltage AC is ‘easy’ due to how well transformers work, how durable they are, and how simple they are. AC does have issues with inductive loss when buried (or near anything conductive), however. For the same reason Transformers work and are awesome. High voltage DC is hard as it requires solid state components which are expensive to make, and prone to blowing up (aka relatively fragile). AC to DC and vice versa also adds non-trivial losses. High voltage DC (to a first approximation) doesn’t suffer from inductive losses however, which makes it much more efficient when near conductive stuff like the ground or seawater. It’s also ‘simpler’ (doesn’t have things like phase or frequency) which is convenient if doing things like transferring power between two power grids with dissimilar frequencies or phase. They each have their place.
    - thmsths 2y ago
      I believe high voltage DC also does not suffer from skin effect. Meaning that the current is transmitted through the whole conductor, not just the surface, leading to less material needed for the same current rating.
      - crote 2y ago
        The skin effect is frequency-related, with higher frequencies resulting in a thinner "skin". The grid frequency is low enough that it doesn't really play a huge role: a 1000mm2 aluminum conductor has a 10% higher resistance at 60Hz AC compared to DC. One thing to remember is that it is common for the conductor to have a strengthening core: this allows operation at a higher temperature (which means a higher current), and it allows for a longer distance between support towers (which means lower construction costs). If you're going to put some poorly-conducting steel or carbon fiber in the center of the conductor anyways, why worry about the skin effect? Besides, those conductors are massive already. At the highest voltage levels, a single set of conductors is carrying multiple gigawatts of power. Even if it were technically viable, would you want to build a single 16GW connection? If it fails, you're going to have serious trouble compensating for that - it's probably wiser to build it as 4x 4GW connections. HVDC also has its own issues with converter losses and not being able to easily step down to lower voltages. It's very nice for distances in the hundreds of kilometers, but it's just not a viable alternative for short city-to-city links.
  - mannykannot 2y ago
    I imagine AC makes things considerably more difficult. Reactance is a consequence of inductance and capacitance, which cause current and voltage changes to be out of phase with each other. While the current on a DC transmission line will vary, it will not be reversing every ~10 milliseconds, and I suppose the voltage will be very steady except during startup and shutdown. On an AC transmission line, I suppose any corona discharge going on shuts off and restarts every time the voltage reverses. They make a characteristic buzz in humid conditions.
  - idiotsecant 2y ago
    That's easy enough to say but big iron power electronics are orders of magnitude more expensive than copper windings and magnetic steel laminations , both in terms of capital cost and maintenance. It's also dramatically harder to extinguish DC arcs so switching gear and substations need more expensive designs as well. The grid could not exist at present, let alone 100 years ago, if we operated it all DC. Over time more and more of it will shift to DC, particularly for long haul, but AC has enough advantages that's it's unlikely to ever go away. I'm short, it's this way for a reason. The complexity is nessessary.
  - thenobsta 2y ago
    All of it, I guess. That phasor is always complex.
    - codethief 2y ago
      Ha, I was waiting to see a comment with the obvious pun to be made here. :) For non-physicists: https://electronics.stackexchange.com/questions/128986/why-use-complex-numbers-to-represent-amplitude-and-phase-of-ac https://electronics.stackexchange.com/questions/128986/why-u...
  - formerly_proven 2y ago
    I think the contrary is true. Frequency and phase matching is a feature, not a bug. Because AC gives you frequency, and frequency is not just easy to measure but also easy to have accurate references and very immune to noise, it is also not influenced by step-up/step-down transformers. This makes balancing an AC grid possible. Frequency below the set point? Increase power output. Frequency above? Reduce. As an added bonus, this happens to exactly match up with how synchronous generators work. So you get a fairly robust way for many distributed power plants to collectively coordinate power output without additional communication just by agreeing on the physical quantity which we can measure with the highest precision of any quantity very cheaply. That is not possible with DC.
    - sam_lowry_ 2y ago
      Bingo! So many people miss this.
  - f1shy 2y ago
    DC comes with another 1000 problems. It wouldn’t be any better, really.
  - api 2y ago
    Is this why some very high power transmission lines are HVDC perhaps?
- belter 2y ago
  Reactance is such a beautiful French word...It just reminds you of some frustrated romantic attempts in a Paris scenario. :-) But your electrical supplier will charge you for it. Had a electrical power teacher with a past employment at a power supplier, who sadly loved to brag how he used to terrorize small farms when their own power generators had a cos φ below 0.98. I think the rule for Portugal is cos φ above 0.97 and for Spain 0.95 also known as el coseno de phi... "Cos-phi compensation" - https://fortop.co.uk/knowledge/white-papers/cos-phi-compensation-cosinus/ https://fortop.co.uk/knowledge/white-papers/cos-phi-compensa...
ANarrativeApe 2y ago
Excellent accessible explanation.
- formerly_proven 2y ago
  All of these seem to be more or less conjecture on a seemingly lost-in-translation phrase though?
Asmod4n 2y ago
Can this be mitigated by putting the cables under ground? Just curious, since it’s a huge debate here at times because of the massive cost of doing so. Germany needs a connection from the coast into the south and most of it as of now will be build under ground.
- SoftTalker 2y ago
  I had always heard that underground is workable for local areas but the really high voltage long-distance lines are hard to insulate undergound (on pylon towers they are not insulated at all).
  - masfuerte 2y ago
    High-voltage DC is frequently used for undersea transmission. This is necessarily insulated. https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current
    - schainks 2y ago
      High voltage DC is effective above ground, too. At high enough voltage, it's actually cost effective and has fewer electrical losses than the AC equivalent. China has been doing some cool investments on high voltage DC in the past 15 years or so. We're talking 750 kV and above IIRC.
      - deleted 2y ago
        [deleted]
      - 1970-01-01 2y ago
        HVDC is the grid's distant future if the future is mostly solar. Why bother inverting to AC if everything making the power is fundamentally changing over to DC?
        crote 2y ago
goda90 2y ago
My state, Wisconsin, has had a long political and legal battle over the construction of high voltage lines from the Madison area to Dubuque, Iowa. Opposition ranges from aesthetics to wildlife conservation to it just being a waste of money. One line of arguments I found intriguing is that the lines should be buried instead of on towers, for a multitude of reasons. The company building it would extract profit and then long term maintenance would fall on the state. If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. Obviously burying such lines has much higher up front costs and the companies looking to profit don't want to pay it.
- lurk2 2y ago
  > If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. You may find this video by Practical Engineering to be interesting: “Repairing Underground Power Cables Is Nearly Impossible” https://www.youtube.com/watch?v=z-wQnWUhX5Y https://www.youtube.com/watch?v=z-wQnWUhX5Y
  - bell-cot 2y ago
    Here's the text version: https://practical.engineering/blog/2021/9/16/repairing-underground-power-cables-is-nearly-impossible https://practical.engineering/blog/2021/9/16/repairing-under... Noteworthy: That power line is only 10 miles long. Madison to Dubuque would be about 10X longer.
  - Animats 2y ago
    That "impossible" line was paired with a new line that doesn't require pumped insulating oil due to better insulating materials. Then the old line was de-energized and repaired, and is kept as a spare.
- toast0 2y ago
  > If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. It's a tradeoff. When there is an issue with underground lines, it's much more expensive to locate and diagnose the fault and repair it; in both dollars and time. In that area of the country, the ground freezes in winter, and digging becomes very difficult, which would make repairs that much more delayed and expensive. Also, depending on requirements, it may be possible to augment capacity ny adding a second transmission line to the existing towers at a later time; that would be much less expensive than setting up the first line; but for undergrounding, such a project would most likely be as expensive as the first time, if not more. Similar with replacing the line at the end of its service life (although if the line and the towers have a similar service life, replacing them both brings costs back up similar to the initial project)
jonlandrum 2y ago
Why were all the answers provided by new contributors? Don't see that very often.
- TacticalCoder 2y ago
  [dead]
- belter 2y ago
  Was posted less than 24 hours ago...
  - jonlandrum 2y ago
    That's not how Stack Exchange works, though. You don't have to register for a new account every time you leave an answer. The replies were all from new accounts, not established ones. I don't think it has anything to do with the amount of time since the question was asked.
- panki27 2y ago
  Not necessarily "new to StackExchange", but at least to the physics site.
- kylehotchkiss 2y ago
  I think a lot of people here would agree that AI/LLMs got them off of stackexchange (not just stack overflow) and it's refreshing to not have to deal with the moderation's instant "did you google" / "duplicate question". These new contributors will learn and switch over to chat.com soon enough
guerby 2y ago
"With inverter-based power storage, generation, and transmission, the grid can now react incredibly quickly. This is good when they do the right thing, but can be very bad when they do the wrong thing." I'm wondering if this will be like the 2016 South Australian blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout "AEMO identified software settings in the wind farms that prevented repeated restarts once voltage or frequency events occurred too often. " Grid operators are currently mostly against renewable and so they impose "blunt" disconnect rules on inverters behind renewable sources, and this comes to bite the grid when the proverbial shit hits the fan. May be in the end this will be a good thing and grid operators will start to treat inverters and renewable as a strength and modify grid regulations as needed.
- reaperducer 2y ago
  Grid operators are currently mostly against renewable As someone who moves a lot, it's always curious to me that grid operators vary so widely on this. Some places (like where I am now), the grid operator hates renewables and especially rooftop solar. Other places, the grid operator will actually subsidize rooftop solar because it they say it reduces the amount of generation it has to do, thus saving money on infrastructure and maintenance. Of course, each location has wildly different climates, but the regional politics aren't that different, so I don't think it's about ideology.
  - shadowgovt 2y ago
    It depends heavily on their market incentives. If the local power company is also in charge of the wires, less load on the wires means less cost. In a market where distribution and generation are different operations, generation only cares about whether anyone's going to buy the electricity they want to put on the wire and you saying "No thanks, I'm full" is in direct competition to their interests (and existence as a firm).
    - idiotsecant 2y ago
      Huh? Transmission networks get directly financially rewarded for more power flowing in the form of wheeling charges. It's wild reading HN discussions of topics that I actually know about. It makes me wonder how much I can trust the discussions I don't know about.
deleted 2y ago
[deleted]
6d6b73 2y ago
It's a fake term, used by the government to hide the real cause - deteriorating magnetic field, that will flip in 15-25 years, but we will start seeing a lot of issues similar to that event more often.
- matkoniecz 2y ago
  [citation needed]
deleted 2y ago
[deleted]
widea 2y ago
April 1 already?
kazinator 2y ago
Accepted answer posits that this may be due to a mistranslation from Spanish, or someone's misunderstanding of an explanation, or both. In other words, the phenomenon is another "vegetative electron microscopy".
- jhayward 2y ago
  That answer has 4 upvotes. A much more electrically literate answer above it, with 35 upvotes, explains in detail that it is a real thing.
  - kazinator 2y ago
    The accepted answer is not electrically illiterate in any way. The upvoted answer, while it may be correct, doesn't argue for the existence of the phenomenon called "induced atmospheric vibration". It may be that it's supposed to refer to corona discharge, which does make a sound ("atmospheric vibration"). But that sound is not the root cause of anything; it is just a side effect of no consequence. It is a plausible hypothesis that "induced atmospheric vibration" it's just someone's misunderstanding (possibly of an explanation similar to what's in that upvoted answer), with some misstranslation being a contributing factor. The two answers simply don't contradict each other.
  - Calwestjobs 2y ago
    government official had to make press conference just to tell people to stop spreading that nonsense you promote as "electrically literate" so that is that. whole stack overflow question is bunch of nonsense, so why do we even argue about it?
rasz 2y ago
Spanish grid operator (Red) preliminary Engineering Report seems to be blaming renewable generation (solar) for the initial drop followed by second drop 1.5 seconds later.
- perching_aix 2y ago
  Where can one find the report? Couldn't find anything on their website or elsewhere. I was only able to find the following media briefing via Reuters [0]: > REE's System Operations Chief Eduardo Prieto told a news briefing the electricity system was hit by a dramatic power generation loss in southwestern Spain, that caused instability in the system that led to its disconnection from the French grid. He said it was quite possible that the affected generation was solar, but it was too early to say for sure. This doesn't quite read like them blaming solar either. If anything, they're painting it as one of the victims of the failure. [0] https://www.reuters.com/world/europe/spanish-grid-operators-first-assessment-rules-out-cyberattack-behind-blackout-2025-04-29/ https://www.reuters.com/world/europe/spanish-grid-operators-...
  - scrlk 2y ago
    I'm going to speculate it was the following: 1. System was running with low inertia due to a high amount of renewable generation (mainly solar). 2. Something caused a large amount of generation to trip. Lack of inertia in the system can't arrest the frequency drop. 3. Rate of change of frequency (ROCOF) protection kicks in and trips renewable generators; interconnectors to France also trip as they are suddenly overloaded. Islanding and blackouts ensue.
acyou 2y ago
I think they might have been referring to conductor gallop, power line sag, and subsequent fault. I read synchronisation failure as downed cable. With extreme temperature variations come extreme winds. Not sure if this was the case.
whitehexagon 2y ago
Interestingly, the recent deadly floods were also blamed on a rare atmospheric event. Sadly, it seems official information during such events is just as rare. No power is unusual, but happens, but no mobile phones, no internet, no emergency broadcasts, SMS or otherwise, just complete silence for hours... and then you hear it might be multi-country wide. Pretty scary. You assume the worst, right? What was also scary to see was how little cash people have. The cash machines went down, queues formed, banks closed, POS terminals failed, and suddenly the smart-world we are building was looking very dumb. Imagine not being able to buy basic essentials like medicines, food and water. Hopefully more people will reject cards / digital money as a result of this crisis. But I also wonder what contribution the massive new solar farms and wind farms had on this crisis. That supply must be quite variable, and subject to rare atmospheric events such as clouds... Sorry to rant, it was a pretty upsetting experience.
- TheOtherHobbes 2y ago
  I did indeed fear the worst, and did a WWIII top-up shop to add some extra essentials to my usual disaster prep. Luckily not needed, but an interesting experience. We were pretty lucky here. The local big box was running on emergency power from its solar roof, and ATMs and card payments were still working - much to my surprise. Smaller stores were taking cash and the larger smaller stores were limiting access and sending customers around individually with staff with torches. A lot of people were obviously prep-shopping, but it was controlled and pretty relaxed. I even had 5G of a sort - intermittent and slow, but I could just about keep up with news updates. In the end it was a 12 hour blackout, which was more of a major inconvenience than the catastrophe that would have happened if it had taken days.
  - whitehexagon 2y ago
    I was also doing my top-up shop, and was surprised how orderly the shelves were being stripped of water and essentials. No panic, maybe some nervous tension, but otherwise could have been a long weekend big shop for most people. I realised my regular disaster prep was lacking in a few areas. I especially want a decent portable radio, and a set of walkie-talkies, but everything looks pretty gimmicky from a quick search. Any reccomendations? I got access to a radio after 3 hours, not that there was anything official at that point, but it was enough to switch down a gear.
perching_aix 2y ago
This news cycle was pretty hilarious (and just as sad) to hunt through. From what I deciphered, the actual suggested cause was "aeolian vibrations" [0], which is one of the three forms of wind-induced conductor vibrations according to this [1] IEEE article. Also known as "flutter" according to Wikipedia [2]. (I'm not in EE so can't confirm nor debunk.) Connected to this, another seemingly made-up term that made the news cycle was "Ging-induced vibrations" (in Portuguese media). Now, I don't speak Portuguese, but all my efforts hunting down this mysterious Ging tremendously failed. However, when I plopped ging into translation models, I couldn't help but notice that "ginga" in Portuguese means "swing", as in cable swing. So I'm giving it pretty reasonable chances that "ging" (no capitalization) might be what "flutter" is in English, i.e. the industry slang for "aeolian vibrations" there. And then the rest was just a typical journo move, much in the way of "the hacker known as 4chan". In any case, it would have been cool if anyone actually linked to where said company made their statement, so that people could independently verify what was actually being said. From what I read, they have since explicitly debunked that they were inventing any new niche atmospheric effects. It's incredibly disheartening that such basic bits of information can become this seriously distorted before going viral, even (especially?) in this day and age. Makes you wonder how trustworthy are the regular news, even biases nonwithstanding, that aren't so readily obvious to be bollocks. [0] https://www.youtube.com/watch?v=j-VzxRfPHjU https://www.youtube.com/watch?v=j-VzxRfPHjU [1] https://ieeexplore.ieee.org/document/4773888 https://ieeexplore.ieee.org/document/4773888 [2] https://en.wikipedia.org/wiki/Stockbridge_damper#Wind-induced_oscillation https://en.wikipedia.org/wiki/Stockbridge_damper#Wind-induce...
- plorg 2y ago
  I'm part of a listserve for power systems engineers (more from academia than from industry) and the consensus seems to be that a couple of trips in short succession caused wild swings in powerflows, resulting in a cascading failure - this is a pretty boring, if consequential, N-2 event, very similar to the 2005 Northeast Blackout in the US.
- miguelmurca 2y ago
  Ginga is a Brasilian Portuguese word. I spent all of the day of the blackout listening to the radio (as you might guess) and not once heard the terms "ging" or "ging-induced". Also, ginga would not be swing as in cable swing, it would be swing as in swing dance (rhythmic movement specifically to music). When possible explanations were put forward in the media, they were attributed, usually either to the portuguese representative of REN (the Chinese company supplying power structure to the country) or to an analogous representative of Spain (where the fault originated). It was always pretty clear that the fault was unknown, since this was stated plainly by the aforementioned representatives and the prime minister. I respect the language barrier, but it would be good to take it into account.

167 points by belter 2y ago

"Diagnosis and Mitigation of Observed Oscillations in IBR-Dominant Power Systems - A PRACTICAL GUIDE" - https://www.esig.energy/wp-content/uploads/2024/10/esig-rpt-oscillations-8.24-print1.pdf https://www.esig.energy/wp-content/uploads/2024/10/esig-rpt-...

juancn 2y ago

"Real electrical systems have to deal with issues of reactance and other exciting math-heavy constructs designed to drive you into some other field of study." They had me at this

SoftTalker 2y ago
Wonder how much complexity using AC adds to this? With DC you would not have to worry about frequency and phase matching. But then you need to convert the DC back to AC at some point.
- deleted 2y ago
  [deleted]
- Cthulhu_ 2y ago
  Some parts of the energy transmission grid are DC, but looks like it's mainly international, undersea, and long-range transmissions: https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current
  - sam_lowry_ 2y ago
    And only because long-distance transmission is more efficient.
- raverbashing 2y ago
  > Wonder how much complexity using AC adds to this? Summarizing a couple of year of very annoying electrical studies: Yes You can't believe how much
  - formerly_proven 2y ago
    On the other hand, having a continent-scale AC grid is not just possible but common. Europe and North Africa have one, Russia has one, China has one, the US has two or three. Meanwhile multiterminal HVDC is basically experimental stuff that's only possible with real-time digital control systems.
    - raverbashing 2y ago
      Having a worldwide data network is also only possible with real-time digital control systems as well The issue is one of technology (having high powered switching components only took of in the last 30? yrs or something) and legacy (Edit: IGBTs are from the 80's though it seems the 1st generation wasn't that great, IGCTs from the late 90s https://mb-drive-services.com/experience-with-igct-based-vfd/ https://mb-drive-services.com/experience-with-igct-based-vfd...
- lazide 2y ago
  (Efficient) High voltage AC is ‘easy’ due to how well transformers work, how durable they are, and how simple they are. AC does have issues with inductive loss when buried (or near anything conductive), however. For the same reason Transformers work and are awesome. High voltage DC is hard as it requires solid state components which are expensive to make, and prone to blowing up (aka relatively fragile). AC to DC and vice versa also adds non-trivial losses. High voltage DC (to a first approximation) doesn’t suffer from inductive losses however, which makes it much more efficient when near conductive stuff like the ground or seawater. It’s also ‘simpler’ (doesn’t have things like phase or frequency) which is convenient if doing things like transferring power between two power grids with dissimilar frequencies or phase. They each have their place.
  - thmsths 2y ago
    I believe high voltage DC also does not suffer from skin effect. Meaning that the current is transmitted through the whole conductor, not just the surface, leading to less material needed for the same current rating.
    - crote 2y ago
      The skin effect is frequency-related, with higher frequencies resulting in a thinner "skin". The grid frequency is low enough that it doesn't really play a huge role: a 1000mm2 aluminum conductor has a 10% higher resistance at 60Hz AC compared to DC. One thing to remember is that it is common for the conductor to have a strengthening core: this allows operation at a higher temperature (which means a higher current), and it allows for a longer distance between support towers (which means lower construction costs). If you're going to put some poorly-conducting steel or carbon fiber in the center of the conductor anyways, why worry about the skin effect? Besides, those conductors are massive already. At the highest voltage levels, a single set of conductors is carrying multiple gigawatts of power. Even if it were technically viable, would you want to build a single 16GW connection? If it fails, you're going to have serious trouble compensating for that - it's probably wiser to build it as 4x 4GW connections. HVDC also has its own issues with converter losses and not being able to easily step down to lower voltages. It's very nice for distances in the hundreds of kilometers, but it's just not a viable alternative for short city-to-city links.
- mannykannot 2y ago
  I imagine AC makes things considerably more difficult. Reactance is a consequence of inductance and capacitance, which cause current and voltage changes to be out of phase with each other. While the current on a DC transmission line will vary, it will not be reversing every ~10 milliseconds, and I suppose the voltage will be very steady except during startup and shutdown. On an AC transmission line, I suppose any corona discharge going on shuts off and restarts every time the voltage reverses. They make a characteristic buzz in humid conditions.
- idiotsecant 2y ago
  That's easy enough to say but big iron power electronics are orders of magnitude more expensive than copper windings and magnetic steel laminations , both in terms of capital cost and maintenance. It's also dramatically harder to extinguish DC arcs so switching gear and substations need more expensive designs as well. The grid could not exist at present, let alone 100 years ago, if we operated it all DC. Over time more and more of it will shift to DC, particularly for long haul, but AC has enough advantages that's it's unlikely to ever go away. I'm short, it's this way for a reason. The complexity is nessessary.
- thenobsta 2y ago
  All of it, I guess. That phasor is always complex.
  - codethief 2y ago
    Ha, I was waiting to see a comment with the obvious pun to be made here. :) For non-physicists: https://electronics.stackexchange.com/questions/128986/why-use-complex-numbers-to-represent-amplitude-and-phase-of-ac https://electronics.stackexchange.com/questions/128986/why-u...
- formerly_proven 2y ago
  I think the contrary is true. Frequency and phase matching is a feature, not a bug. Because AC gives you frequency, and frequency is not just easy to measure but also easy to have accurate references and very immune to noise, it is also not influenced by step-up/step-down transformers. This makes balancing an AC grid possible. Frequency below the set point? Increase power output. Frequency above? Reduce. As an added bonus, this happens to exactly match up with how synchronous generators work. So you get a fairly robust way for many distributed power plants to collectively coordinate power output without additional communication just by agreeing on the physical quantity which we can measure with the highest precision of any quantity very cheaply. That is not possible with DC.
  - sam_lowry_ 2y ago
    Bingo! So many people miss this.
- f1shy 2y ago
  DC comes with another 1000 problems. It wouldn’t be any better, really.
- api 2y ago
  Is this why some very high power transmission lines are HVDC perhaps?
belter 2y ago
Reactance is such a beautiful French word...It just reminds you of some frustrated romantic attempts in a Paris scenario. :-) But your electrical supplier will charge you for it. Had a electrical power teacher with a past employment at a power supplier, who sadly loved to brag how he used to terrorize small farms when their own power generators had a cos φ below 0.98. I think the rule for Portugal is cos φ above 0.97 and for Spain 0.95 also known as el coseno de phi... "Cos-phi compensation" - https://fortop.co.uk/knowledge/white-papers/cos-phi-compensation-cosinus/ https://fortop.co.uk/knowledge/white-papers/cos-phi-compensa...

ANarrativeApe 2y ago

Excellent accessible explanation.

formerly_proven 2y ago
All of these seem to be more or less conjecture on a seemingly lost-in-translation phrase though?

Asmod4n 2y ago

Can this be mitigated by putting the cables under ground? Just curious, since it’s a huge debate here at times because of the massive cost of doing so. Germany needs a connection from the coast into the south and most of it as of now will be build under ground.

SoftTalker 2y ago
I had always heard that underground is workable for local areas but the really high voltage long-distance lines are hard to insulate undergound (on pylon towers they are not insulated at all).
- masfuerte 2y ago
  High-voltage DC is frequently used for undersea transmission. This is necessarily insulated. https://en.wikipedia.org/wiki/High-voltage_direct_current https://en.wikipedia.org/wiki/High-voltage_direct_current
  - schainks 2y ago
    High voltage DC is effective above ground, too. At high enough voltage, it's actually cost effective and has fewer electrical losses than the AC equivalent. China has been doing some cool investments on high voltage DC in the past 15 years or so. We're talking 750 kV and above IIRC.
    - deleted 2y ago
      [deleted]
    - 1970-01-01 2y ago
      HVDC is the grid's distant future if the future is mostly solar. Why bother inverting to AC if everything making the power is fundamentally changing over to DC?
      - crote 2y ago

goda90 2y ago

My state, Wisconsin, has had a long political and legal battle over the construction of high voltage lines from the Madison area to Dubuque, Iowa. Opposition ranges from aesthetics to wildlife conservation to it just being a waste of money. One line of arguments I found intriguing is that the lines should be buried instead of on towers, for a multitude of reasons. The company building it would extract profit and then long term maintenance would fall on the state. If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. Obviously burying such lines has much higher up front costs and the companies looking to profit don't want to pay it.

lurk2 2y ago
> If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. You may find this video by Practical Engineering to be interesting: “Repairing Underground Power Cables Is Nearly Impossible” https://www.youtube.com/watch?v=z-wQnWUhX5Y https://www.youtube.com/watch?v=z-wQnWUhX5Y
- bell-cot 2y ago
  Here's the text version: https://practical.engineering/blog/2021/9/16/repairing-underground-power-cables-is-nearly-impossible https://practical.engineering/blog/2021/9/16/repairing-under... Noteworthy: That power line is only 10 miles long. Madison to Dubuque would be about 10X longer.
- Animats 2y ago
  That "impossible" line was paired with a new line that doesn't require pumped insulating oil due to better insulating materials. Then the old line was de-energized and repaired, and is kept as a spare.
toast0 2y ago
> If the lines were buried, there'd be less maintenance caused by weather events, less transmission losses, and overall more efficient and resilient operation. It's a tradeoff. When there is an issue with underground lines, it's much more expensive to locate and diagnose the fault and repair it; in both dollars and time. In that area of the country, the ground freezes in winter, and digging becomes very difficult, which would make repairs that much more delayed and expensive. Also, depending on requirements, it may be possible to augment capacity ny adding a second transmission line to the existing towers at a later time; that would be much less expensive than setting up the first line; but for undergrounding, such a project would most likely be as expensive as the first time, if not more. Similar with replacing the line at the end of its service life (although if the line and the towers have a similar service life, replacing them both brings costs back up similar to the initial project)

jonlandrum 2y ago

Why were all the answers provided by new contributors? Don't see that very often.

TacticalCoder 2y ago
[dead]
belter 2y ago
Was posted less than 24 hours ago...
- jonlandrum 2y ago
  That's not how Stack Exchange works, though. You don't have to register for a new account every time you leave an answer. The replies were all from new accounts, not established ones. I don't think it has anything to do with the amount of time since the question was asked.
panki27 2y ago
Not necessarily "new to StackExchange", but at least to the physics site.
kylehotchkiss 2y ago
I think a lot of people here would agree that AI/LLMs got them off of stackexchange (not just stack overflow) and it's refreshing to not have to deal with the moderation's instant "did you google" / "duplicate question". These new contributors will learn and switch over to chat.com soon enough

guerby 2y ago

"With inverter-based power storage, generation, and transmission, the grid can now react incredibly quickly. This is good when they do the right thing, but can be very bad when they do the wrong thing." I'm wondering if this will be like the 2016 South Australian blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout https://en.wikipedia.org/wiki/2016_South_Australian_blackout "AEMO identified software settings in the wind farms that prevented repeated restarts once voltage or frequency events occurred too often. " Grid operators are currently mostly against renewable and so they impose "blunt" disconnect rules on inverters behind renewable sources, and this comes to bite the grid when the proverbial shit hits the fan. May be in the end this will be a good thing and grid operators will start to treat inverters and renewable as a strength and modify grid regulations as needed.

reaperducer 2y ago
Grid operators are currently mostly against renewable As someone who moves a lot, it's always curious to me that grid operators vary so widely on this. Some places (like where I am now), the grid operator hates renewables and especially rooftop solar. Other places, the grid operator will actually subsidize rooftop solar because it they say it reduces the amount of generation it has to do, thus saving money on infrastructure and maintenance. Of course, each location has wildly different climates, but the regional politics aren't that different, so I don't think it's about ideology.
- shadowgovt 2y ago
  It depends heavily on their market incentives. If the local power company is also in charge of the wires, less load on the wires means less cost. In a market where distribution and generation are different operations, generation only cares about whether anyone's going to buy the electricity they want to put on the wire and you saying "No thanks, I'm full" is in direct competition to their interests (and existence as a firm).
  - idiotsecant 2y ago
    Huh? Transmission networks get directly financially rewarded for more power flowing in the form of wheeling charges. It's wild reading HN discussions of topics that I actually know about. It makes me wonder how much I can trust the discussions I don't know about.

deleted 2y ago

[deleted]

6d6b73 2y ago

It's a fake term, used by the government to hide the real cause - deteriorating magnetic field, that will flip in 15-25 years, but we will start seeing a lot of issues similar to that event more often.

matkoniecz 2y ago
[citation needed]

deleted 2y ago

[deleted]

widea 2y ago

April 1 already?

kazinator 2y ago

Accepted answer posits that this may be due to a mistranslation from Spanish, or someone's misunderstanding of an explanation, or both. In other words, the phenomenon is another "vegetative electron microscopy".

jhayward 2y ago
That answer has 4 upvotes. A much more electrically literate answer above it, with 35 upvotes, explains in detail that it is a real thing.
- kazinator 2y ago
  The accepted answer is not electrically illiterate in any way. The upvoted answer, while it may be correct, doesn't argue for the existence of the phenomenon called "induced atmospheric vibration". It may be that it's supposed to refer to corona discharge, which does make a sound ("atmospheric vibration"). But that sound is not the root cause of anything; it is just a side effect of no consequence. It is a plausible hypothesis that "induced atmospheric vibration" it's just someone's misunderstanding (possibly of an explanation similar to what's in that upvoted answer), with some misstranslation being a contributing factor. The two answers simply don't contradict each other.
- Calwestjobs 2y ago
  government official had to make press conference just to tell people to stop spreading that nonsense you promote as "electrically literate" so that is that. whole stack overflow question is bunch of nonsense, so why do we even argue about it?

rasz 2y ago

Spanish grid operator (Red) preliminary Engineering Report seems to be blaming renewable generation (solar) for the initial drop followed by second drop 1.5 seconds later.

perching_aix 2y ago
Where can one find the report? Couldn't find anything on their website or elsewhere. I was only able to find the following media briefing via Reuters [0]: > REE's System Operations Chief Eduardo Prieto told a news briefing the electricity system was hit by a dramatic power generation loss in southwestern Spain, that caused instability in the system that led to its disconnection from the French grid. He said it was quite possible that the affected generation was solar, but it was too early to say for sure. This doesn't quite read like them blaming solar either. If anything, they're painting it as one of the victims of the failure. [0] https://www.reuters.com/world/europe/spanish-grid-operators-first-assessment-rules-out-cyberattack-behind-blackout-2025-04-29/ https://www.reuters.com/world/europe/spanish-grid-operators-...
- scrlk 2y ago
  I'm going to speculate it was the following: 1. System was running with low inertia due to a high amount of renewable generation (mainly solar). 2. Something caused a large amount of generation to trip. Lack of inertia in the system can't arrest the frequency drop. 3. Rate of change of frequency (ROCOF) protection kicks in and trips renewable generators; interconnectors to France also trip as they are suddenly overloaded. Islanding and blackouts ensue.

acyou 2y ago

I think they might have been referring to conductor gallop, power line sag, and subsequent fault. I read synchronisation failure as downed cable. With extreme temperature variations come extreme winds. Not sure if this was the case.

whitehexagon 2y ago

Interestingly, the recent deadly floods were also blamed on a rare atmospheric event. Sadly, it seems official information during such events is just as rare. No power is unusual, but happens, but no mobile phones, no internet, no emergency broadcasts, SMS or otherwise, just complete silence for hours... and then you hear it might be multi-country wide. Pretty scary. You assume the worst, right? What was also scary to see was how little cash people have. The cash machines went down, queues formed, banks closed, POS terminals failed, and suddenly the smart-world we are building was looking very dumb. Imagine not being able to buy basic essentials like medicines, food and water. Hopefully more people will reject cards / digital money as a result of this crisis. But I also wonder what contribution the massive new solar farms and wind farms had on this crisis. That supply must be quite variable, and subject to rare atmospheric events such as clouds... Sorry to rant, it was a pretty upsetting experience.

TheOtherHobbes 2y ago
I did indeed fear the worst, and did a WWIII top-up shop to add some extra essentials to my usual disaster prep. Luckily not needed, but an interesting experience. We were pretty lucky here. The local big box was running on emergency power from its solar roof, and ATMs and card payments were still working - much to my surprise. Smaller stores were taking cash and the larger smaller stores were limiting access and sending customers around individually with staff with torches. A lot of people were obviously prep-shopping, but it was controlled and pretty relaxed. I even had 5G of a sort - intermittent and slow, but I could just about keep up with news updates. In the end it was a 12 hour blackout, which was more of a major inconvenience than the catastrophe that would have happened if it had taken days.
- whitehexagon 2y ago
  I was also doing my top-up shop, and was surprised how orderly the shelves were being stripped of water and essentials. No panic, maybe some nervous tension, but otherwise could have been a long weekend big shop for most people. I realised my regular disaster prep was lacking in a few areas. I especially want a decent portable radio, and a set of walkie-talkies, but everything looks pretty gimmicky from a quick search. Any reccomendations? I got access to a radio after 3 hours, not that there was anything official at that point, but it was enough to switch down a gear.

perching_aix 2y ago

This news cycle was pretty hilarious (and just as sad) to hunt through. From what I deciphered, the actual suggested cause was "aeolian vibrations" [0], which is one of the three forms of wind-induced conductor vibrations according to this [1] IEEE article. Also known as "flutter" according to Wikipedia [2]. (I'm not in EE so can't confirm nor debunk.) Connected to this, another seemingly made-up term that made the news cycle was "Ging-induced vibrations" (in Portuguese media). Now, I don't speak Portuguese, but all my efforts hunting down this mysterious Ging tremendously failed. However, when I plopped ging into translation models, I couldn't help but notice that "ginga" in Portuguese means "swing", as in cable swing. So I'm giving it pretty reasonable chances that "ging" (no capitalization) might be what "flutter" is in English, i.e. the industry slang for "aeolian vibrations" there. And then the rest was just a typical journo move, much in the way of "the hacker known as 4chan". In any case, it would have been cool if anyone actually linked to where said company made their statement, so that people could independently verify what was actually being said. From what I read, they have since explicitly debunked that they were inventing any new niche atmospheric effects. It's incredibly disheartening that such basic bits of information can become this seriously distorted before going viral, even (especially?) in this day and age. Makes you wonder how trustworthy are the regular news, even biases nonwithstanding, that aren't so readily obvious to be bollocks. [0] https://www.youtube.com/watch?v=j-VzxRfPHjU https://www.youtube.com/watch?v=j-VzxRfPHjU [1] https://ieeexplore.ieee.org/document/4773888 https://ieeexplore.ieee.org/document/4773888 [2] https://en.wikipedia.org/wiki/Stockbridge_damper#Wind-induced_oscillation https://en.wikipedia.org/wiki/Stockbridge_damper#Wind-induce...

plorg 2y ago
I'm part of a listserve for power systems engineers (more from academia than from industry) and the consensus seems to be that a couple of trips in short succession caused wild swings in powerflows, resulting in a cascading failure - this is a pretty boring, if consequential, N-2 event, very similar to the 2005 Northeast Blackout in the US.
miguelmurca 2y ago
Ginga is a Brasilian Portuguese word. I spent all of the day of the blackout listening to the radio (as you might guess) and not once heard the terms "ging" or "ging-induced". Also, ginga would not be swing as in cable swing, it would be swing as in swing dance (rhythmic movement specifically to music). When possible explanations were put forward in the media, they were attributed, usually either to the portuguese representative of REN (the Chinese company supplying power structure to the country) or to an analogous representative of Spain (where the fault originated). It was always pretty clear that the fault was unknown, since this was stated plainly by the aforementioned representatives and the prime minister. I respect the language barrier, but it would be good to take it into account.