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

On 5/14/2025 7:16 AM, Glen Walpert wrote:

On Tue, 13 May 2025 07:50:36 -0700, Don Y wrote:
 

On 5/13/2025 6:26 AM, Glen Walpert wrote:

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

>
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 30 years, which is when a former employer did some work on a
SCADA upgrade project for the Egyptian Electrical Authority.  A search
on 'SCADA radio link' will turn up several vendors.

>
And they used these to control instantaneous frequency and phase?  Or,
just coarse data collection and /supervisory/ control?

 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-time" means different things to different applications.
I took Theo's upthread suggestion to mean broadcasting a *reference*
that all genertors would track -- instead of using the actual power line,
itself.  I.e., the spain event could have been avoided if such a broadcast
reference were used by each generator DISREGARDING THE ACTUAL POWER SIGNAL.
I.e., a zero-crossing should occur.... NOW.   And, NOW.  And NOW.  Even
if what the generator is OBSERVING seems to differ.
SCADA systems tend to operate at higher levels than the REAL real-time
control AT the field.
E.g., a tablet press produces tablets at ~200Hz.  Controlling the details
of the actual process isn't going to happen at the far end of an RF link;
there's too much latency and not enough determinism.
However, you could tell the press to change it's operating conditions
"when it can get around to it" from a supervisory/control station
on the other side of the planet.  Relying on the *local* RT controls
to ensure all of the product made while those status and control
messages are in flight are actually made properly.
Like counting on the generator's local controls to keep it producing power
under the previously established settings based on LOCAL observations...
while its status and control messages are on the wing.