If the South Australian example is anything to go by, the UK grid may just lack fast-acting battery powered inverters to catch shut-down transients fast enough.
Once Telsa's 100MW 129MW.hour battery was installed, it took over from whatever had been providing short term phase and voltage control and made about $50 million (most of its purchase price) from selling these services to the grid in its first year.
It also stopped a wave of shut-downs in two adjacent states from knocking anything off-line in South Australia. This happened not all that long after it's installation, and generated a bit of gloating.
This may be the bit of kit that a renewables-heavy grid needs, but hadn't realised that they needed until they saw one working.
You mention 16:52 and yet the shutdowns occurred after 16:55. I think you are verifying my claim. If you look at the data you linked to, it also sho ws maximum frequency deviation prior to 16:55. West Midlands shows frequen cies below 49.5 as early as 16:52:44.
Here is the data I saw on 15 second measurements rather than 1 minute. By
16:55 the frequency is back to 49.5 Hz.
Date UTC Hz
20190809 155230 50.003
20190809 155245 49.248
20190809 155300 49.104
20190809 155315 49.23
20190809 155330 49.202
20190809 155345 48.889 It is clear already that the relatively high proportion of renewables at
Lol! Again, jumping to conclusions without any evidence. Why do you insis t on doing that? Heck, most of the renewables in the UK is wind which clea rly does have inertia and can easily be used to stabilize the grid if desig ned to do that.
Do you realize that makes literally no sense? If it was true that the wind farm applied strict df/dt and delta f rules it would have tripped earlier, not later. The max deviations were all prior to the gas generation going offline i.e. before 16:55.
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u are verifying my claim. If you look at the data you linked to, it also s hows maximum frequency deviation prior to 16:55. West Midlands shows frequ encies below 49.5 as early as 16:52:44.
y 16:55 the frequency is back to 49.5 Hz.
The frequency deviations are the "event". The shutdowns are consequences of the event. Feed the wrong kind of transient into a system, and you get inc reasing deviations until something trips out. The deviations can swing from positive to negative in the process.
you are verifying my claim. If you look at the data you linked to, it also shows maximum frequency deviation prior to 16:55. West Midlands shows fre quencies below 49.5 as early as 16:52:44.
By 16:55 the frequency is back to 49.5 Hz.
of the event. Feed the wrong kind of transient into a system, and you get i ncreasing deviations until something trips out. The deviations can swing fr om positive to negative in the process.
But that's not what happened. I don't see any evidence of "increasing devi ations". The max deviation was some time before any power shut down. The system was restoring itself and was already to the point of frequency being better than 49.5 Hz before any shut down.
No one has explained the initial deviation and I'm pretty sure I haven't se en anyone say the gas generator went offline as a result of any "deviations ". The only report I've seen is that the gas generator went offline becaus e the aggregate power usage dropped below some number. Even then I don't s ee why they would just shut down the generator output at once rather than r educing it gradually over some minutes so the system could take up the slac k. Then the system can make an adjustment and take up the slack with the r emaining generation facilities.
It's interesting that no one has mentioned what event could or would have c aused the initial frequency deviation.
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k you are verifying my claim. If you look at the data you linked to, it al so shows maximum frequency deviation prior to 16:55. West Midlands shows f requencies below 49.5 as early as 16:52:44.
. By 16:55 the frequency is back to 49.5 Hz.
s of the event. Feed the wrong kind of transient into a system, and you get increasing deviations until something trips out. The deviations can swing from positive to negative in the process.
viations". The max deviation was some time before any power shut down. Th e system was restoring itself and was already to the point of frequency bei ng better than 49.5 Hz before any shut down.
"The system" isn't a single unit in an isolated box. What you are looking a t is the sum of the actions of the system at a particular point. That the s ummed effects of the deviation at that particular point had got the frequen cy back up to 49.5Hz is not evidence that components parts weren't in troub le.
seen anyone say the gas generator went offline as a result of any "deviatio ns". The only report I've seen is that the gas generator went offline beca use the aggregate power usage dropped below some number. Even then I don't see why they would just shut down the generator output at once rather than reducing it gradually over some minutes so the system could take up the sl ack. Then the system can make an adjustment and take up the slack with the remaining generation facilities.
That sort of control is done by automatic machinery, acting on the conditio ns at it's connection to the grid, which aren't going to be the conditions at the point where your record was taken.
caused the initial frequency deviation.
There are always lightning strikes ... Putting it another way, a utility sy stem with a long history of working with high inertia generators is unlikel y to have the kind of distributed monitoring that will let it record fast and localised transients, even if a bunch of the new generators feeding the system can trip out fast enough to react to such events.
ink you are verifying my claim. If you look at the data you linked to, it also shows maximum frequency deviation prior to 16:55. West Midlands shows frequencies below 49.5 as early as 16:52:44.
te. By 16:55 the frequency is back to 49.5 Hz.
ces of the event. Feed the wrong kind of transient into a system, and you g et increasing deviations until something trips out. The deviations can swin g from positive to negative in the process.
deviations". The max deviation was some time before any power shut down. The system was restoring itself and was already to the point of frequency b eing better than 49.5 Hz before any shut down.
at is the sum of the actions of the system at a particular point. That the summed effects of the deviation at that particular point had got the frequ ency back up to 49.5Hz is not evidence that components parts weren't in tro uble.
"In trouble"??? What does that mean in technical terms???
You seem to be missing the point that something caused the frequency deviat ion that led to the observed problems. People are talking as if the genera tion shut down LED to the problem. In reality it seems to have been a symp tom. However, there appears to be no connection between the gas generator shut down (which was done in regards to the total power level, not the freq uency glitch) and the initial frequency deviation. Perhaps the wind farm w as a result of the frequency deviation that was prior to the gas generator shut down. So there are no clear cause and effect connections between any of these events.
t seen anyone say the gas generator went offline as a result of any "deviat ions". The only report I've seen is that the gas generator went offline be cause the aggregate power usage dropped below some number. Even then I don 't see why they would just shut down the generator output at once rather th an reducing it gradually over some minutes so the system could take up the slack. Then the system can make an adjustment and take up the slack with t he remaining generation facilities.
ions at it's connection to the grid, which aren't going to be the condition s at the point where your record was taken.
So the frequency is not the same at all points? I guess there can be some small phase differences due to the resistive effects of conductors vs. the reactive power draws. But even that won't cause much of a frequency deviat ion. It would require phase differences exceeding 360 degrees.
ve caused the initial frequency deviation.
system with a long history of working with high inertia generators is unlik ely to have the kind of distributed monitoring that will let it record fas t and localised transients, even if a bunch of the new generators feeding t he system can trip out fast enough to react to such events.
Like I said, no one has mentioned any event that could have caused the init ial problem. I've not heard anyone talk about lightning impacts at the tim e of the initial frequency deviation. Have you?
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The benefit of inertia from still spinning rotors to frequency stability only happens if there is still an electrical connection and field magnet
- that is lost if breakers trip and disconnect.
I wonder if the reason the gas powered station timing shows it disconnected *after* the frequency droop is because the disconnect time you are looking at is some human-determined officially-deemed disconnect time and not the actual, earlier, time the breakers actuated?
Alternatively, one report I saw wrote that the wind farm was supplying
800MW when it disconnected and the gas plant was smaller at 730MW so it could have been the smaller gas plant was not able to make up the power loss and then dropped out?
Yes, many reports have talked about a lightning strike shutting down one of the generators - where they have differed is that some say the wind farm was struck and others say the gas plant!
as wrong. I saw in another group that the frequency drop (the trigger for most of the load shedding) happened some minutes before the gas plant went offline and that a couple minutes before the wind farmwent offline. So it is not at all clear what was cause and what was effect.
have been published online with timestamps that match that event see for ex ample:
inside a five minute period and then bounced back. 16:52:44 - 16:57:00
think you are verifying my claim. If you look at the data you linked to, i t also shows maximum frequency deviation prior to 16:55. West Midlands sho ws frequencies below 49.5 as early as 16:52:44.
nute. By 16:55 the frequency is back to 49.5 Hz.
ences of the event. Feed the wrong kind of transient into a system, and you get increasing deviations until something trips out. The deviations can sw ing from positive to negative in the process.
g deviations". The max deviation was some time before any power shut down. The system was restoring itself and was already to the point of frequency being better than 49.5 Hz before any shut down.
ng at is the sum of the actions of the system at a particular point. That t he summed effects of the deviation at that particular point had got the fre quency back up to 49.5Hz is not evidence that components parts weren't in t rouble.
Not delivering the current into the grid that it should have at that instan t. How else could a generator be in trouble?
ation that led to the observed problems. People are talking as if the gene ration shut down LED to the problem. In reality it seems to have been a sy mptom.
Actually,a consequence.
t down (which was done in regards to the total power level, not the frequen cy glitch) and the initial frequency deviation. Perhaps the wind farm was a result of the frequency deviation that was prior to the gas generator shu t down. So there are no clear cause and effect connections between any of these events.
Maybe nothing obvious. Sadly, causes and effects work these things out for themselves inside the system, and aren't under any obligation to post messa ges about what is actually going on.
n't seen anyone say the gas generator went offline as a result of any "devi ations". The only report I've seen is that the gas generator went offline because the aggregate power usage dropped below some number. Even then I d on't see why they would just shut down the generator output at once rather than reducing it gradually over some minutes so the system could take up th e slack. Then the system can make an adjustment and take up the slack with the remaining generation facilities.
itions at it's connection to the grid, which aren't going to be the conditi ons at the point where your record was taken.
Signals take time to propagate. Grid connections aren't designed as constan t impedance transmission lines.
fects of conductors vs. the reactive power draws. But even that won't caus e much of a frequency deviation. It would require phase differences exceed ing 360 degrees.
Frequency is the integral of phase. What's going through the grid is curren t. Look at the current for long enough, and you can extract a frequency. I f the grid is shutting down at the time, this probably isn't worth doing.
have caused the initial frequency deviation.
They've probably got enough sense not to shoot their mouths off until they have got all the data together and gone through it.
y system with a long history of working with high inertia generators is unl ikely to have the kind of distributed monitoring that will let it record f ast and localised transients, even if a bunch of the new generators feeding the system can trip out fast enough to react to such events.
itial problem. I've not heard anyone talk about lightning impacts at the t ime of the initial frequency deviation. Have you?
No. But that's one place that hard-to-predict transients can come from.
you are verifying my claim. If you look at the data you linked to, it also shows maximum frequency deviation prior to 16:55. West Midlands shows fre quencies below 49.5 as early as 16:52:44.
By 16:55 the frequency is back to 49.5 Hz.
at
e
s.
nsist on doing that? Heck, most of the renewables in the UK is wind which clearly does have inertia and can easily be used to stabilize the grid if d esigned to do that.
in
d
wind farm applied strict df/dt and delta f rules it would have tripped earl ier, not later. The max deviations were all prior to the gas generation go ing offline i.e. before 16:55.
You should read the facts. I have no reason to believe the timestamp of th e gas generator shutdown was recorded by a human rather than automatically. It seems very unlikely. The claim was the gas generator was "shut down" automatically because the total grid usage dropped below some amount. This is rather the opposite of load shedding, generation shedding. I can't und erstand why they would drop it all at once rather than reducing it graduall y so the system could adjust. It seems hard on both ends, the generation a nd the grid.
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was wrong. I saw in another group that the frequency drop (the trigger fo r most of the load shedding) happened some minutes before the gas plant wen t offline and that a couple minutes before the wind farmwent offline. So i t is not at all clear what was cause and what was effect.
s have been published online with timestamps that match that event see for example:
r inside a five minute period and then bounced back. 16:52:44 - 16:57:00
I think you are verifying my claim. If you look at the data you linked to, it also shows maximum frequency deviation prior to 16:55. West Midlands s hows frequencies below 49.5 as early as 16:52:44.
minute. By 16:55 the frequency is back to 49.5 Hz.
quences of the event. Feed the wrong kind of transient into a system, and y ou get increasing deviations until something trips out. The deviations can swing from positive to negative in the process.
ing deviations". The max deviation was some time before any power shut dow n. The system was restoring itself and was already to the point of frequen cy being better than 49.5 Hz before any shut down.
king at is the sum of the actions of the system at a particular point. That the summed effects of the deviation at that particular point had got the f requency back up to 49.5Hz is not evidence that components parts weren't in trouble.
ant. How else could a generator be in trouble?
You tell me, it was your statement. Instead of being snarky about it, why not just be clear.
If the generator was "in trouble", then the grid would have been dropping f requency. The issue is that the grid frequency dropped for no explained re ason, then when it was recovering and within spec, meaning most of the grid was producing more power than was drawn two facilities went offline. One supposedly because the total power of the grid dropped below some figure an d the other, two minutes later, dropped off for no explained reason.
When you talk about being "in trouble", what "components parts" are you ref erring to?
viation that led to the observed problems. People are talking as if the ge neration shut down LED to the problem. In reality it seems to have been a symptom.
First, that is not demonstrated as yet. No evidence has been provided. Th e one shutdown was claimed to have been because of normal, expected operati on having nothing to do with the frequency deviation. The other has not be en explained at all.
hut down (which was done in regards to the total power level, not the frequ ency glitch) and the initial frequency deviation. Perhaps the wind farm wa s a result of the frequency deviation that was prior to the gas generator s hut down. So there are no clear cause and effect connections between any o f these events.
r themselves inside the system, and aren't under any obligation to post mes sages about what is actually going on.
Ah, you mean it is all a mystery? Yes, let's get Columbo on the job!
ven't seen anyone say the gas generator went offline as a result of any "de viations". The only report I've seen is that the gas generator went offlin e because the aggregate power usage dropped below some number. Even then I don't see why they would just shut down the generator output at once rathe r than reducing it gradually over some minutes so the system could take up the slack. Then the system can make an adjustment and take up the slack wi th the remaining generation facilities.
nditions at it's connection to the grid, which aren't going to be the condi tions at the point where your record was taken.
ant impedance transmission lines.
So how many microseconds, millseconds??? Seconds perhaps? Lol. If any pa rt of the system gets behind in frequency by the amounts mentioned by any s ignificant fraction of a second, the current will be flowing back into gene rators and loads will receive zero power. Even at 50 Hz 10 ms is 180 degrees out of phase. At 49.5 Hz that only take s 1 second.
effects of conductors vs. the reactive power draws. But even that won't ca use much of a frequency deviation. It would require phase differences exce eding 360 degrees.
ent. Look at the current for long enough, and you can extract a frequency. If the grid is shutting down at the time, this probably isn't worth doing.
d have caused the initial frequency deviation.
y have got all the data together and gone through it.
You mean because they don't yet know. Yep.
ity system with a long history of working with high inertia generators is u nlikely to have the kind of distributed monitoring that will let it record fast and localised transients, even if a bunch of the new generators feedi ng the system can trip out fast enough to react to such events.
initial problem. I've not heard anyone talk about lightning impacts at the time of the initial frequency deviation. Have you?
They don't happen invisibly. Lightning strikes are not very subtle.
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at was wrong. I saw in another group that the frequency drop (the trigger for most of the load shedding) happened some minutes before the gas plant w ent offline and that a couple minutes before the wind farmwent offline. So it is not at all clear what was cause and what was effect.
tes have been published online with timestamps that match that event see fo r example:
ver inside a five minute period and then bounced back. 16:52:44 - 16:57:00
I think you are verifying my claim. If you look at the data you linked t o, it also shows maximum frequency deviation prior to 16:55. West Midlands shows frequencies below 49.5 as early as 16:52:44.
1 minute. By 16:55 the frequency is back to 49.5 Hz.
sequences of the event. Feed the wrong kind of transient into a system, and you get increasing deviations until something trips out. The deviations ca n swing from positive to negative in the process.
asing deviations". The max deviation was some time before any power shut d own. The system was restoring itself and was already to the point of frequ ency being better than 49.5 Hz before any shut down.
ooking at is the sum of the actions of the system at a particular point. Th at the summed effects of the deviation at that particular point had got the frequency back up to 49.5Hz is not evidence that components parts weren't in trouble.
stant. How else could a generator be in trouble?
y not just be clear.
I thought it was clear.
frequency.
That might be one kind of trouble.
n when it was recovering and within spec, meaning most of the grid was prod ucing more power than was drawn two facilities went offline. One supposedl y because the total power of the grid dropped below some figure and the oth er, two minutes later, dropped off for no explained reason.
"Explained reasons" are what you find in detailed reports, written by peopl e who have spent time poring over all the information available.
You can complain that these reports should appear faster, but that doesn't get us anywhere.
eferring to?
How would I know? The whole discussion has been restricted to what you coul d see at a downstream output.
deviation that led to the observed problems. People are talking as if the generation shut down LED to the problem. In reality it seems to have been a symptom.
There was stuff going on on the grid before the shut-downs happen. This may be just a coincidence, but this seems rather unlikely. the one thing you c an rely on about causes is that they precede effects.
because of normal, expected operation having nothing to do with the freque ncy deviation. The other has not been explained at all.
shut down (which was done in regards to the total power level, not the freq uency glitch) and the initial frequency deviation. Perhaps the wind farm w as a result of the frequency deviation that was prior to the gas generator shut down. So there are no clear cause and effect connections between any of these events.
for themselves inside the system, and aren't under any obligation to post m essages about what is actually going on.
Columbo wasn't trained in investigating that kind of mystery. The industry has its own trouble-shooters and data analysts,and they may eventually wor k out what was going on. They may not tell the general public about it.
haven't seen anyone say the gas generator went offline as a result of any " deviations". The only report I've seen is that the gas generator went offl ine because the aggregate power usage dropped below some number. Even then I don't see why they would just shut down the generator output at once rat her than reducing it gradually over some minutes so the system could take u p the slack. Then the system can make an adjustment and take up the slack with the remaining generation facilities.
conditions at it's connection to the grid, which aren't going to be the con ditions at the point where your record was taken.
stant impedance transmission lines.
part of the system gets behind in frequency by the amounts mentioned by any significant fraction of a second, the current will be flowing back into ge nerators and loads will receive zero power.
Miles of wire have inductance. Thinking in term of propagation delays proba bly isn't useful.
kes 1 second.
The utility generators try to keep in the current being propagated as close to 50Hz as they can. When the grid gets perturbed the current stop looking like nice pure sine waves. The fact that the current deviates from a pure
50Hz sine is clear evidence of a problem, but doesn't necessarily tell you much about the nature of the problem.
e effects of conductors vs. the reactive power draws. But even that won't cause much of a frequency deviation. It would require phase differences ex ceeding 360 degrees.
rrent. Look at the current for long enough, and you can extract a frequenc y. If the grid is shutting down at the time, this probably isn't worth doin g.
uld have caused the initial frequency deviation.
hey have got all the data together and gone through it.
ility system with a long history of working with high inertia generators is unlikely to have the kind of distributed monitoring that will let it reco rd fast and localised transients, even if a bunch of the new generators fee ding the system can trip out fast enough to react to such events.
e initial problem. I've not heard anyone talk about lightning impacts at t he time of the initial frequency deviation. Have you?
what was wrong. I saw in another group that the frequency drop (the trigge r for most of the load shedding) happened some minutes before the gas plant went offline and that a couple minutes before the wind farmwent offline. So it is not at all clear what was cause and what was effect.
sites have been published online with timestamps that match that event see for example:
over inside a five minute period and then bounced back. 16:52:44 - 16:57:0
0
I think you are verifying my claim. If you look at the data you linked to, it also shows maximum frequency deviation prior to 16:55. West Midlan ds shows frequencies below 49.5 as early as 16:52:44.
n 1 minute. By 16:55 the frequency is back to 49.5 Hz.
onsequences of the event. Feed the wrong kind of transient into a system, a nd you get increasing deviations until something trips out. The deviations can swing from positive to negative in the process.
reasing deviations". The max deviation was some time before any power shut down. The system was restoring itself and was already to the point of fre quency being better than 49.5 Hz before any shut down.
looking at is the sum of the actions of the system at a particular point. That the summed effects of the deviation at that particular point had got t he frequency back up to 49.5Hz is not evidence that components parts weren' t in trouble.
instant. How else could a generator be in trouble?
why not just be clear.
ng frequency.
hen when it was recovering and within spec, meaning most of the grid was pr oducing more power than was drawn two facilities went offline. One suppose dly because the total power of the grid dropped below some figure and the o ther, two minutes later, dropped off for no explained reason.
ple who have spent time poring over all the information available.
t get us anywhere.
I'm not complaining about the reports. I'm complaining about people acting like they already have the reports... and the answers.
referring to?
uld see at a downstream output.
Exactly, yet it doesn't keep you from speculating.
y deviation that led to the observed problems. People are talking as if th e generation shut down LED to the problem. In reality it seems to have bee n a symptom.
ay be just a coincidence, but this seems rather unlikely. the one thing you can rely on about causes is that they precede effects.
en because of normal, expected operation having nothing to do with the freq uency deviation. The other has not been explained at all.
r shut down (which was done in regards to the total power level, not the fr equency glitch) and the initial frequency deviation. Perhaps the wind farm was a result of the frequency deviation that was prior to the gas generato r shut down. So there are no clear cause and effect connections between an y of these events.
t for themselves inside the system, and aren't under any obligation to post messages about what is actually going on.
y has its own trouble-shooters and data analysts,and they may eventually w ork out what was going on. They may not tell the general public about it.
I believe these sorts of reports are generally public.
I haven't seen anyone say the gas generator went offline as a result of any "deviations". The only report I've seen is that the gas generator went of fline because the aggregate power usage dropped below some number. Even th en I don't see why they would just shut down the generator output at once r ather than reducing it gradually over some minutes so the system could take up the slack. Then the system can make an adjustment and take up the slac k with the remaining generation facilities.
e conditions at it's connection to the grid, which aren't going to be the c onditions at the point where your record was taken.
onstant impedance transmission lines.
y part of the system gets behind in frequency by the amounts mentioned by a ny significant fraction of a second, the current will be flowing back into generators and loads will receive zero power.
bably isn't useful.
Of course it is. That's one factor in the grid that we have at least some information on. The delays can't allow excessive phase differences. Wavin g hands about "inductance, inductance" is of no value since no one has sugg ested any way it would have been a factor other than to muddy the waters to some unknown degree.
takes 1 second.
se to 50Hz as they can. When the grid gets perturbed the current stop looki ng like nice pure sine waves. The fact that the current deviates from a pur e 50Hz sine is clear evidence of a problem, but doesn't necessarily tell yo u much about the nature of the problem.
The issue is that the power *did* lose frequency and it was minutes before any of the generators shut down or any of the loads were reported to have g one off line. Talking about non-sinusoidal currents is not of much value. You seem to toss a lot of turds into the punch bowl without actually makin g any effort to explain anything.
ive effects of conductors vs. the reactive power draws. But even that won' t cause much of a frequency deviation. It would require phase differences exceeding 360 degrees.
current. Look at the current for long enough, and you can extract a freque ncy. If the grid is shutting down at the time, this probably isn't worth do ing.
would have caused the initial frequency deviation.
they have got all the data together and gone through it.
utility system with a long history of working with high inertia generators is unlikely to have the kind of distributed monitoring that will let it re cord fast and localised transients, even if a bunch of the new generators f eeding the system can trip out fast enough to react to such events.
the initial problem. I've not heard anyone talk about lightning impacts at the time of the initial frequency deviation. Have you?
m.
I guess it's like horseshoes and hand grenades, close counts too.
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Rick C.
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Here is the type of battery that really is needed.
"In the U.S., the Silicon Valley-based firm introduced its new battery tech nology called Megapack last month that Pacific Gas & Electric Co. plans to use in California. Mitsubishi Hitachi Power Systems is developing high-capa city batteries for a 1,000-megawatt venture in Utah that it touts as the wo rld's largest renewable-energy storage project."
A GW of power in one installation. Not bad. It's not even a Tesla so no f ree Supercharging.
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y what was wrong. I saw in another group that the frequency drop (the trig ger for most of the load shedding) happened some minutes before the gas pla nt went offline and that a couple minutes before the wind farmwent offline. So it is not at all clear what was cause and what was effect.
w sites have been published online with timestamps that match that event se e for example:
ll over inside a five minute period and then bounced back. 16:52:44 - 16:57 :00
:55. I think you are verifying my claim. If you look at the data you link ed to, it also shows maximum frequency deviation prior to 16:55. West Midl ands shows frequencies below 49.5 as early as 16:52:44.
han 1 minute. By 16:55 the frequency is back to 49.5 Hz.
consequences of the event. Feed the wrong kind of transient into a system, and you get increasing deviations until something trips out. The deviation s can swing from positive to negative in the process.
ncreasing deviations". The max deviation was some time before any power sh ut down. The system was restoring itself and was already to the point of f requency being better than 49.5 Hz before any shut down.
re looking at is the sum of the actions of the system at a particular point . That the summed effects of the deviation at that particular point had got the frequency back up to 49.5Hz is not evidence that components parts were n't in trouble.
t instant. How else could a generator be in trouble?
, why not just be clear.
ping frequency.
then when it was recovering and within spec, meaning most of the grid was producing more power than was drawn two facilities went offline. One suppo sedly because the total power of the grid dropped below some figure and the other, two minutes later, dropped off for no explained reason.
eople who have spent time poring over all the information available.
n't get us anywhere.
ng like they already have the reports... and the answers.
So you are slapping yourself on the wrist.
ou referring to?
could see at a downstream output.
About the only speculation I've allowed myself was the proposition that a l ightning strike might have had a part in the event.
ncy deviation that led to the observed problems. People are talking as if the generation shut down LED to the problem. In reality it seems to have b een a symptom.
may be just a coincidence, but this seems rather unlikely. the one thing y ou can rely on about causes is that they precede effects.
You posted a list of voltage and frequency observations. That isn't much ev idence, but it is something.
ration having nothing to do with the frequency deviation. The other has no t been explained at all.
tor shut down (which was done in regards to the total power level, not the frequency glitch) and the initial frequency deviation. Perhaps the wind fa rm was a result of the frequency deviation that was prior to the gas genera tor shut down. So there are no clear cause and effect connections between any of these events.
out for themselves inside the system, and aren't under any obligation to po st messages about what is actually going on.
try has its own trouble-shooters and data analysts,and they may eventually work out what was going on. They may not tell the general public about it.
Eventually. In some form or other.
Being close enough to a human observer is one thing. Being close enough to a power line or sub-station is something else.
chnology called Megapack last month that Pacific Gas & Electric Co. plans t o use in California. Mitsubishi Hitachi Power Systems is developing high-ca pacity batteries for a 1,000-megawatt venture in Utah that it touts as the world's largest renewable-energy storage project."
free Supercharging.
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The entry lists seven installations, none of them all that big. Apparently there's one being installed in China at the moment that's going to be 200MW and 800MW.hour when all the bits are in place.
One GigaWatt would be appreciably bigger, but high technology puff pieces d o like to make that kind of claim.
Dinorwig in the UK is 1.728 GW and can store 9.1 GW.hours, but it has been there since 1984, and is pumped water. It predates "renewable power" so the puff writer seems to have felt free to ignore it.
In Australia the Snowy 2 scheme will be able to deliver 2GW and store 350 G W.hours, if it does get built.
The frequency (and voltage) dip and load shedding was all over inside a
*COMPLETE AND UTTER BOLLOCKS*
The LFDD shutdowns started in earnest once the frequency breached the lower limit of 48.8Hz at 16:53:50 and continued until the frequency rose to 50Hz (and then overshot slightly). Until that point it was mostly local systems making self protection decisions based on f and/or df/dt.
They claim publicly that a lightning strike on a transmission line close to Little Barford took out 1 of three generators there and that this was followed "seconds" later by Hornsea suddenly dropping out (itself a bit surprising since East Anglia was a lot closer to ground zero). Then cascade failure at Little Barford took out the rest of that plant as well as various smaller local players. The sum of these exceeded their spare capacity by almost a factor of two and so to halt the cascade failure they dropped 5% of load off the grid under LFDD rules.
The railways own protection systems just went haywire and were *NOT* disconnected by Nation Grid the damage they had was all self inflicted!
The initial report is out but finding a copy online is rather hard. This makes me suspicious. I have now found a copy marked Highly Confidential
- I don't know how long it will stay there:
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It isn't highlighted in the summary but the timeline of events shows that some sort of over sensitivity on the part of the bulk component
747MW of Hornsea wind farm was responsible for bringing the network down. The report summary is very careful not to draw attention to the detailed timeline which shows that Hornsea probably went down first! Barford timestamps at present are only good to the nearest second.
Hornsea started deloading just 230ms after the transient blue phase fault and the first generator at Barford within 1s. It is fair to say that the lightning strike probably initiated both events.
Barford was *very* close to the lightning strike see map on page 8.
See page 11 "Timeline of Events" and p13 "Annotated frequency chart"
They imply that the protection systems at Hornsea have since been adjusted to make them somewhat more tolerant of ms transient faults. See page 14.
It may well be that they both dropped off together but the Little Barford only lost the first 244MW steam turbine whereas Hornsea lost
737MW. A small part of Hornsea continued to supply a meagre 62MW.
Little Barford's other generators soldiered on but GT1A tripped about a minute after the initial failure and GT1B was manually shut down 30s after that. By then load shedding was well under way since frequency was a long way out of spec and at 48.8 had triggered a full LFDD response.
National Grid appear to have performed extremely well to manage the situation in real time even if the knock on effects were substantial. It was all over bar the shouting in just under 5 minutes clock time.
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