The Spanish Grid Drop-out - recently released information.

Yes, in essence voltage and frequency are all that must to be monitored. I think the unfortunate thing is to date most co-generation has been designed to follow the grid but now their share is greater their algorithms need to be updated to more closely participate in contributing to the grid rather than passively following?

I don't think that using broadcast radio for real time mains grid control is a good idea. It would be far too unreliable.

To first order, power plants adjust the power injected into the grid by observing the grid frequency. When the frequency drops, the injected power is increased.

This says nothing about the dynamic behaviour, which is far more involved, and variable too. Apparently there are some issues with that on the European grid.

Jeroen Belleman

It would affect earth rotation, too. Some huge water reservoir in China is affecting it already.

...

It only requires that enough of the larger more powerful systems cooperate and that automatic load shedding occurs fast enough and with the right amount to prevent cascade network failure when things go bad. Spain seems to have got the latter catastrophically wrong.

UK wasn't too good in 2019 either.

They are all connected to the national grid. The grid frequency target and voltage is extremely well known and all that is needed is for each unit that can to try and drive the grid voltage and frequency towards that target. Things get iffy when they drop out a lot of stuff all at once because they are using the same rules and rapid collapse follows.

The big fat controller is already needed for any national grid. The UK once made the mistake of letting BBC TV into the main National Grid control room live in the late 60's and the interviewer asked innocently if the live displays meant that if everyone watching switched on their kettle the needle would shift. An edict went out afterwards to the effect of never again will any live broadcast team be allowed on site.

The whole thing seems to be messy with the domestic ones made down to a price being rather less able to cope with surprises. Only some of the BESS systems are configured for frequency stabilisation. Their main objective is to make money for their investors by time shifting power.

It can sense if the voltage and/or frequency is too high or too low and if it has output margin available act to counter it. This is only really worthwhile if it has some stored battery energy reserve to draw upon. The grid being overloaded is more common than over supplied (and there are consumers of last resort that can load balance to some extent).

Wind power scaling as cube of windspeed means that quite often wind Scottish wind farms are paid to feather their turbine blades because the cables are far too feeble to carry the power away.

Big problem in daytime is that most of the BESS systems are running flat out supplying power to industry and consumers so that they don't have a lot of reserve to offer if things start to go wrong. Likewise when a failure happens in the early evening peak consumption 6pm-8pm.

Peak demand premium pricing means they all want a slice of that cake.

Big steam tubines with lots of spinning inertia and boilers full of gigajoules of superheated water. And enough 24/7 local generation so we don't need to import power from France.

And no commitments to take (or pay for) power that we don't need.

Three Gorges Dam?

.

Joe

Cogen means extracting power (like otherwise waste heat) from some process.

One rooftop solar array is parts-per-million of a national power system. One more or less is unlikely to crash the system... although it could.

One anchor dragged across the underwater feed from an offshore wind farm could be interesting.

Yep.

Spinning inertia and boilers fulln of super=heated steam are just energy reservoirs. So are grid scale batteries. Getting excited about the former and ignoring the latter is clear evidence of sloppy thinking.

Back in 2008 the book

Nobody likes the idea that their assets are being used without their explicit permission, but participants would be paid for their help.

Point to point RF links have been in use in (mostly hard wired) grid control SCADA (System Control And Data Acquisition) systems for at least

And when the voltage drops injected reactive power is increased.

Basler is a major manufacturer of generator controls for grid connected generators, and they have available to anyone supplying a verifiable company email a 'Technical Paper: Genset Control and Protection' under technical resources tab of:

UL also has an overview of worldwide grid connect standards available for email address - 'UL Grid Code Compliance eBook' search should turn it up, you will need a list of protective relay numbers to interpret it.

The most interesting of protective relays is 21, the distance relay, absolutely essential for grid coordination (tripping only the breaker closest to the fault).

Eventually those issues will be discussed in detail in the trade press if not elsewhere.

Estimated at 60 ns/day, similar to the effect of the moon, except that the moon's deceleration effect is cumulative.

They don't need to. Our politicians know they have to do his bidding or we're sunk.

That's what the California RUle 21 for Solar Inverters attempts.

As the frequency rises above 60Hz the inverter linearly reduces its power output to assist in grid stability. Similar actions apply as the voltage increases. There are additional rules for how the unit is to reconnect after a grid failure.

Future versions of the rules will include remote monitoring and control but currently they are purely based on local grid frequency and voltage.

And the investors building the stations do not consider the cost of managing the waste for centuries. They leave that part to the government. In Spain, we don't have any long term nuclear waste storage. I think we rent storage in France, so the waste has to be transported there. We have some storage at each station, a large water pool.

Right.

No, it isn't. Fuel was a factor, of course, but not the only one.

I'll pray to that.

Sounds good to me.

It would. John Larkin thinks that Donald trump has "common sense". The rest of the world is more skeptical. They have noticed that his "liberation day" tariff scared stock markets around the world into dramatic sell-offs, now largely reversed as he has back-pedalled.

The take-away message is that Donald Trumps "bidding" is more of a try-on than any kind of enforceable demand.

SCADA is used to monitor and control the grid, where control is done in real time by adjusting the set points for real and reactive power at all controlled power sources. A small percentage of sources being inaccessible degrades control by an insignificant amount.

Real power is regulated by the prime mover governors, which must be operated in droop mode in order to share the load (the speed set point is reduced with increasing load). The grid Hz/Gw figure which has been mentioned is not directly related to generator inertia, where insignificant energy is stored, it is the aggregate droop setting of the prime mover governors feeding the grid. After speed/frequency shift (the governors only measure shaft speed) due to a load change the grid control center adjusts the governor set points to bring the frequency back to normal.

Voltage regulation is entirely separate and is done by setting the reactive power output of sources, again by adjusting set points in real time over SCADA (or one of the other approved standard comm protocols). This is a bit complex for a quick explanation but is described in detail in any decent text covering synchronous generator control.

Voltage regulation is more likely to be a stability issue than frequency. If you take two widely separated generators or sets of locally paralleled generators at two power plants which are optimally tuned for stand alone operation and connect them with a long transmission line, voltage will begin to oscillate due to the time delay in locally detecting changes in the other plants output. Detuning the regulators to achieve stability results in inadequate response to load changes - thus central control of both plants over SCADA.

Large generator voltage response time is limited by the L/R time constant, which will be in the 10's of seconds, over a minute for some large multi- pole hydroelectric generators. Inverters can respond much faster, with potentially worse stability issues, and dividing power sources into many small units does not make stability any easier, you still can't set optimal tuning parameters for widely separated groups of sources which will be both stable and fast, central control of some percentage of source set points is required. This problem and it's solution is well understood and the current generation of inverters are designed to allow remote control of set points.

In the US more than 2/3 of all solar power is utility owned 10 MW or larger and all of this is under central grid operator control, so no stability issues there.

More intermittent power sources need more batteries, which are being deployed by utilities as fast as they can be manufactured, being far cheaper then peaking gas turbines, the most expensive of power sources.

Glen

The best thing to do with used fuel rods is reprocess them into more fuel.

When that's not feasible, dig a deep hole and dump it in. Or drop barrels of junk into an ocean subduction zone.

It's irrational to store nuclear waste locally. Nuke policy is mostly fear driven. And nukes are unpopular in some quarters by people who really don't want us to have affordable, safe energy.

Today the ministry said that they have ruled out a hacking of the REE, but not in other places. And that it originated in Granada, Badajoz and Sevilla (loss of generation).

Spanish:

Aagesen says that the generation disconnections before the blackout began in Granada, Badajoz and Seville.

They began with a substation in Granada and then occurred in Badajoz and Seville; the vice-president speaks of ‘overvoltage’ problems, rules out a cyber-attack on Red Eléctrica and stresses that ‘hypotheses have already been ruled out’: it was not a problem of coverage, reserve ‘or the size of the networks’.

The Third Vice-President and Minister for Ecological Transition, Sara Aagesen, announced this Wednesday in the Congress of Deputies that the generation losses prior to the historic blackout on 28 April ‘began in Granada, Badajoz and Seville’. Aagesen, who confirmed that a cyber-attack on Red Eléctrica has been ruled out, spoke of problems of ‘overvoltage’ in the system and explained that they are analysing whether the oscillations detected in Europe half an hour before the cut were related to the incident.

In an appearance in the plenary session to explain the crisis, the vice-president explained that, after ‘at least two periods of oscillations’ in the 30 minutes prior to the blackout, which were detected in the peninsular and European system, with “low” demand at that time, there were ‘three losses’ of generation: the first, ‘in a substation in Granada’ at 12 hours, 32 minutes and 57 seconds; 19 seconds later, another substation in Badajoz was disconnected; and 20.3 seconds later, another in Seville. ‘The sum of these three events’ accumulated a loss of just over 2.2 gigawatts ‘in 20 seconds’.

The committee investigating the blackout is analyzing “disconnections that may be due to overvoltage as a triggering element of the cascading drop” that came just after. The control systems of the different operators reflect that that morning “recorded volatility in the voltages”, previous: “Rises and falls” prior to that zero and those oscillations. That is why they are analyzing “not only that morning”, but also the days prior to the blackout.

Aagesen explained that after these disconnections in these three provinces, the synchronism with the European system was lost: the interconnections with France jump, the Iberian Peninsula is isolated from the rest of the continent and the “deregulation” occurs, that is, the demand ceases to be fed. After disconnecting “the first step of deregulation”, the frequency in the grid “continues to drop” and “successive steps of deregulation” are activated in a short period of time. At 12 hours, 33 minutes and 22 seconds “the sixth time step of dredging” is activated and the system ends up collapsing to “peninsular zero”.

The Vice-president explained that the inter-ministerial committee that is analyzing the causes of the incident, which has already held six meetings and has a group dedicated to the electricity system and another for cybersecurity, is analyzing “millions of data with the best equipment on behalf of the Administration”. He stated that the collaboration of the sector's agents is being “full”. Information has been requested from more than thirty generation control centers, distributors and aggregations of large generation productions above

Translated with DeepL.com (free version)

(... continues on the link)