Re: The Spanish Grid Drop-out - recently released information.

On 12/05/2025 18:35, john larkin wrote:

On Sun, 11 May 2025 12:22:11 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
 

On 11/05/2025 5:04 am, john larkin wrote:
>

As solar and wind get to be dominant, micromanagement of power sources
and loads will be necessary to ensure uptime.

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.

This is largely unnecessary - if the control signal that was being sent
out by the central controller to micromanage each power source was
derived from a function of the frequency, phase, voltage etc., then
rather than trying to distribute the result of this calculation to
millions of devices with low latency, it is better to distribute just
the formula (once every few years or as necessary), and run it on a
microcontroller in the inverters several times every mains cycle. They
already have more than enough processing power.

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.

A central (international!) controller would want to know what every
contributor was pushing into the grid, and probably see wind flow and
clouds moving around. One local transmission line could fail and take
down half of Europe. Again.

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.
https://www.bbc.co.uk/programmes/b00vkjmy
Unfortunately the series where it is mentioned is no longer available to stream.

The rapid control algorithms should be distributed, and the only
low-latency communication signals they should rely upon are frequency
and voltage.

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.

A solar panel with an algorithm can't now about potential system
overloads. Solar and wind will have to be shed sometimes to protect
the entire system. Loads shed too. Renewable-heavy grids are fragile.

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.
--
Martin Brown