What is "Induced Atmospheric Vibration"?

Question

The blackout seen today on the Iberian Peninsula has been attributed to a "rare" phenomenon known as "induced atmospheric vibration":

It says that "due to extreme temperature variations in the interior or Spain, there were anomalous oscillations in the very high voltage lines (400 KV), a phenomenon known as 'induced atmospheric vibration'".

"These oscillations caused synchronisation failures between the electrical systems, leading to successive disturbances across the interconnected European network."

Unfortunately, I am unable to find any paper or article explaining this effect. What is it?

Answer 1

Anyone who’s had to build a power system rapidly learns that electricity is not as simple as “electrons move, and work gets done”. 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.

Power grids experience this on an epic scale. They have to concern themselves with a few needs simultaneously:

• ensuring electrical potential doesn’t sag under load (maintaining voltage)
• ensuring the integrity of the AC waveform (maintaining frequency)
• ensuring the system doesn’t lose too much energy to fighting its own electromagnetic behavior (controlling the power factor)

That last one is the part that is profoundly nonintuitive. Capacitance and inductance inherent to the system create a sort of inertia in the system that must be fought to provide those other two guarantees. Together they work to create what’s called “reactance”.

Long range lines and the equipment they connect to can have a lot of reactance. High voltages make it even weirder.

One of the strange things that you don’t experience at lower voltages is corona discharge. Very high electrical potentials cause the air around the conductors to become ionized. When sufficiently ionized, this creates discharges.

You can see static examples of this natural phenomenon in the form of St. Elmo's fire. This often precedes a lightning strike if the potential difference is extreme enough.

But power transmission systems are not static. They fluctuate dynamically with the AC waveform. This causes situations where discharges or perturbation in fields that create them act as a new component of the reactance of the system.

Modeling this is very complicated and very important. Real power transmission systems have active components that work to provide the above guarantees. Most of the time, they are modeled well and tune things to keep the voltage and frequency where it should be with a minimum of losses due to reactance.

But these corona discharges are unlike the other two components of reactance, because they are affected by the environment outside of the system. Consider… what affects the voltages at which ionized air molecules might cause a discharge? Temperature and humidity do.

And now we finally reach the part where “induced atmospheric vibrations” starts to make sense. When things get hotter or drier, discharges happen more readily. And when they happen, they tend to happen at a given frequency.

When that happens, the active components of the transmission system try to reduce the reactance; but they can’t. They aren’t built to deal with this kind of reactance and the models that drive them make incorrect assumptions (e.g., some increase in capacitance means we need to adjust the phase angle).

This would work fine in a system without these discharges. With the discharges, it’s ineffective. And, since both ends of the connection may be actively doing things that make the problem worse, they can get themselves so far out of sync that they’re basically burning power competing with each other (instead of working together like normal).

This is what took down the grid. Unexpected components of reactance appeared due to corona discharges because of atmospheric conditions. From there, automatic safeguards designed to keep the grid in sync were ineffective or even counterproductive. The grid decohered and everything shut down as safeguards tripped in a cascade.

As the grid gets more modern, it also exacerbates these problems. When big spinning generators were driving the grid, they could only act so fast. This created a kind of inertia that damped oscillations created by responses to these issues.

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 it can be very bad when they do the wrong thing.

As the weather grows hotter, the grid also sees more of these previously unusual conditions, too. Today they formed a kind of “perfect storm”. In the future, we will likely see this more often until they find ways to counteract, mitigate, or model these issues.

You can read more about this phenomenon in Seven bad effects of corona on transmission lines.

Answer 2

And you won't find it: either it's an erroneous translation into English, or the politician didn't understand the technical explanations given to him.

Weather changes can lead to uneven load - somewhere the heating is turned on en masse, and somewhere - air conditioning. Therefore, the frequency of local generators can begin to decrease, but in unified electrical networks ALL generators must rotate strictly synchronously! And, in order to avoid catastrophic current pulsations, the automatic frequency unloading protection is activated, which disconnects the problematic section. The load is distributed to other generators and the problem can be committed by another generator.

It is important that before this, the line feeding Spain from France was disconnected - which could compensate for the lack of generated power and stabilize the situation. The result is load fluctuations caused by segment shutdowns and a complete collapse of the network.

Answer 3

The UK Guardian cites experts: Spain and Portugal power outage: what caused it, and was there a cyber-attack?

“Due to the variation of the temperature, the parameters of the conductor change slightly,” said Taco Engelaar, managing director at Neara, a software provider to energy utilities. “It creates an imbalance in the frequency.”

Georg Zachmann, a senior fellow at Bruegel, a Brussels think tank, said the system had suffered “cascading disconnections of power plants” – including one in France – when the frequency of the grid dropped below the European standard of 50 Hz.

The high voltage (HV) lines have capacitance, inductance and resistance. Resistance changes with temperature, and so does capacitance. So the impedance of the HV lines changes slightly as function of temperature (Impedance Z = square root ( inductance / capacitance).

However: how the (slightly) changing impedance of the HV lines would influence the frequency of the current they remains a mystery to me. But the change in impedance could lead to an impedance mismatch and thus to standing waves on the HV lines, which would cause higher-than-expected voltages at certain locations in the HV lines.

Answer 4

I don't have an answer, but I've found a detailed paper entitled "Atmospheric resonances and their coupling to vibrations of the ground and waves in the ocean".

It's not the answer to your question, but there appears to be some clues in there, where it's discussing different atmospheric resonant types, and quiet a few links to reference materials.

It's, at the very least, the start of a rabbit trail that I think will lead to the answer. I've only started my investigations, as I too have never heard of this, and am quite intrigued as to how this triggered a blackout of this magnitude

I found an entire paper on how to deal with oscillation problems in interconnected grids.

Oscillations can result when the control settings of the automatic generation control (AGC) (or possibly multiple AGCs) are incompatible with the primary frequency response of resources in the subject systems. The risk of this type of miscoordination increases with the rise of IBRs and the more dramatic diurnal and weather-driven swings in dispatches, flows, and resource mixes.

Diagnosis and Mitigation of Observed Oscillations in IBR-Dominant Power Systems A PRACTICAL GUIDE

The paper has much more insight, but as I understand it, the power generators are synchronised together at very precise frequencies, and the infrasound waves generated by heat variance caused the power lines to oscillate in a way that caused the power generators to go out of sync with each other. It's much more complex than that, but I believe that this is the gist of what the atmospheric induced vibrations are that they are referencing.

Answer 5

Humidity and temperature indeed could lead to increased corona and then to discharge, secondly line capacitance and inductance changes. Single discharge or a train of discharges could lead to creation of standing waves in long transmission line.

Answer 6

There is a very subtle issue involved with A/C power generation that few green energy advocates are aware of. A/C voltage and frequency must be tightly controlled as demand increases and decreases. Due to mass and energy conservation issues, the variability in demand must be offset by a variability in some other process variable in order to keep the grid stable. As an example, for a turbo-generator, as electrical demand increases, there is a slight sag in A/C frequency, and the control scheme increases steam to the turbine to correct this sag. Thus, the variability in demand is offset by a variability in steam consumption.

For wind turbines and solar cells, there is a lot of variability in power generation as well as variability in demand. That variability must also be redistributed to some process variable, but that job is a lot more complicated given uncontrolled variability in power generation. In principle, big batteries could fix this problem, but an economic analysis indicates that batteries big enough to deal with anything other than very short term power shortfalls would be prohibitively expensive.

The root cause of the recent power outage in Spain and Portugal hasn't yet been publicized, but it is certain that "induced atmospheric vibration" is not the root cause. It is somewhat more likely that the variability of both supply and demand of grid electrical energy caused a situation where either supply could not meet demand or demand was too low to match supply, and the amount of mismatch was too large to distribute that variability to the "usual" process variable.

Answer 7

It's a nonsense explanation made up by politicians. No one knows about "a phenomenon known as 'induced atmospheric vibration'".

There isn't any evidence whatsoever of weather anomalies on the Iberian Peninsula either. Oscillations occur in large-scale grids of course, but "induced atmospheric vibration" sounds to me like whoever wrote the statement barely understood the technical explanation.

Right now the whole country is in crisis mode. Let's wait for a proper investigation.

Answer 8

This is a really interesting phenomenon and point, and I’m not a scientist myself, but based on what everyone’s said—and just thinking through it—I think the main issue seems to be, well, environmental conditions messing with the expected electrical behaviour in the system. Like, to put it super simply (even though it’s obviously more complicated), it’s as if the atmosphere outside the cable is creating a kind of potential imbalance with what’s going on inside the cable. And while these high-voltage systems usually do have models and safeguards to compensate for that kind of thing, the problem is when those models don’t include edge-case conditions—like a sudden, unusually dry period that no one really saw coming or planned for.

If you remember, just a month ago, the Iberian Peninsula had tons of rain—like one of the wettest months of the year. So the models might’ve still been tuned to that moisture-rich environment. But now it’s suddenly very, very dry, and that dry air increases the likelihood of static discharge. And this is where things like corona discharge come in. So—again, this is a simplified way to think about it—but voltage and current inside the cable can kind of be thought of like pressurised water. And if the insulation and environmental parameters aren’t behaving as expected, that pressure can escape in the form of discharge into the surrounding air.

That’s essentially what corona discharge is: it’s when the electric field around a high-voltage conductor becomes strong enough to ionise the air around it, leading to current “leaking” into the atmosphere—not in a useful or controlled way, but as waste or interference. It’s not always dangerous in small amounts, but it is a sign that something’s not optimal.

So, if this kind of leakage was happening:

• It could’ve dropped the voltage or current levels in one part of the grid

• That drop might’ve triggered a safety response—a trip—in that segment

• But if the response wasn’t fast or effective enough, that trip could cause an imbalance elsewhere

• That next segment then trips, and so on

• You get a cascading effect—a domino chain of shutdowns

And just to give context—15 gigawatts is huge. So whatever happened, it wasn’t just a glitch in one small area. And while corona discharge on its own might not be enough to knock out a system that size, if it was happening at multiple points under extreme conditions (like ultra-dry air, possibly with high ambient temperature), it makes sense that the grid wasn’t reacting fast enough to stabilise itself.

Think of it like this: if you’re in your kitchen and you turn on the kettle, the oven, the microwave, and the heater all at once, you might trip the circuit breaker. Not because any one thing is broken, but because the system is only designed to handle so much current at a time. What’s happening inside the grid is similar—except instead of too much current, in this case it’s more like certain parts of the system aren’t getting enough. So when one part sees a drop, it shuts down to protect itself, and that shifts the load onto other parts, which then also trip, one after another.

If the voltage dips even just a few percent—and if the system isn’t prepared to handle that dynamically in real time—then that can be enough to set off a larger failure. The fact that it all came down to weather conditions that weren’t expected or properly accounted for just shows how much these kinds of systems rely on accurate modelling. And when that modelling is off—even by a little—the knock-on effects can be massive.