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Low grid frequency or dodgy data
Posted: 22 Sep 2019, 13:00
by adam2
According to the dynamic demand website, the UK grid frequency has been low and unstable for at least the last 40 minutes.
http://www.dynamicdemand.co.uk/grid.htm
The indicated frequency has routinely fallen below the normal operating limit of 49-8 cycles, and has briefly dropped to below the legal limit of 49-5. cycles.
This seems rather surprising under the prevailing circumstances of;
Modest load
No unusual frequency disturbances shown on the national grid site, though that has a lower resolution.
No OCGT plant running, according to gridwatch.
No unusual percentage of renewable generation.
I therefore wonder if the dynamic demand site is in error. A local power failure might have occurred, and we are might therefore be seeing the frequency of local standby generator rather than the grid.
OTOH, I have found no report of a power cut at the physical address of gridwatch.
All very odd, anyone know more ?
Posted: 22 Sep 2019, 14:41
by adam2
UPDATE
The indicated grid frequency from gridwatch is still low and variable, after nearly 3 hours.
Must be dodgy data.
No way would the national grid allow the actual frequency to remain that low for so long.
Posted: 23 Sep 2019, 23:23
by Mr. Fox
The DD meter is bouncing around all over the show.
It doesn't tally with my own (measured) logs or the data on
Gridwatch and there's nothing significant on
BMReports.
I guess DD need to get their soldering iron out again (or learn how to use the BMR API).
How the meter works
We soldered together a simple circuit to measure the AC grid frequency. It does this using a low-cost microprocessor to time the interval between each change in direction of electric current from a normal power socket.
The circuit is connected via an interface board to a web-linked computer which takes a reading of the grid frequency every second. The computer passes this value to a script on our web server where it is then saved.
http://www.dynamicdemand.co.uk/grid.htm#
Posted: 23 Sep 2019, 23:32
by adam2
I have contacted Dynamic demand and they have confirmed that the frequency meter is not working as it should.
Hopefully they will soon fix it.
Posted: 24 Sep 2019, 11:59
by adam2
Now fixed.
Posted: 20 Nov 2019, 13:45
by adam2
But now broken again.
The frequency meter on the dynamic demand website is now stuck at 50.015 cycles. An entirely plausible figure, but remaining at exactly the same figure, no way. Now fixed
Posted: 27 Oct 2020, 13:41
by adam2
There is some dodgy data on the gridwatch site at present. Over the last 24 hours, there have been numerous almost instantaneous changes in total demand and an input from different sources.
Such rapid changes are most improbable and suggest dodgy data. A sudden drop in demand of say 10% implies that 10% of the nation was blacked out.
Nothing on the news or indeed on this website, so dodgy data.
The gridwatch site is IMHO most interesting, but dont forget to apply the "commonsense test"
Re: Low grid frequency or dodgy data
Posted: 26 Oct 2021, 17:36
by adam2
Some dodgy data today on gridwatch.
PV production shown as zero all day, impossible ! PV is very limited at this time of year, but NEVER zero.
Re: Low grid frequency or dodgy data
Posted: 02 Jun 2024, 15:20
by adam2
Dodgy data on the Gridwatch site at present.
Wind power, CCGT, and nuclear showing as unchanged for the last 36 hours. Virtually impossible.
The Gridwatch site can be an interesting/useful source of data, but don't forget to apply the common-sense test to any unexpected figures.
Re: Low grid frequency or dodgy data
Posted: 12 Jun 2024, 22:39
by adam2
Still the same after nearly two weeks.
Wind, nuclear, and CCGT output showing as completely unchanged since the beginning of the month.
Gridwatch used to do better than this !
I have emailed them without result, anyone else want to try ? in case action is related to the number of emails received.
Re: Low grid frequency or dodgy data
Posted: 13 Jun 2024, 08:56
by Ralphw2
the MyGridGB site lost its data feed at the same time. It restarted a few days ago. Obviously the data feed changed in some way. I indirectly know the author of gridwatch, I might be able to pass on a message.
Re: Low grid frequency or dodgy data
Posted: 13 Jun 2024, 18:50
by adam2
Ralphw2 wrote: ↑13 Jun 2024, 08:56
the MyGridGB site lost its data feed at the same time. It restarted a few days ago. Obviously the data feed changed in some way. I indirectly know the author of gridwatch, I might be able to pass on a message.
It would IMO be helpful if you can contact them, I find viewing the Gridwatch site interesting and cant be the only person interested in such things.
Re: Low grid frequency or dodgy data
Posted: 23 Jun 2024, 22:12
by Ralphw2
The author of Gridwatch has been in hospital an is convalescing alone in a remote house. I will pass on the message when he is in better shape.
Re: Low grid frequency or dodgy data
Posted: 23 Jun 2024, 22:29
by adam2
Thanks for that.
Re: Low grid frequency or dodgy data
Posted: 02 Jul 2024, 17:42
by adam2
Still not working, after more than a month.
Does Ralph, or anyone else, have any news regarding the health of the author ?