When I phoned UKPN, the girlie said when the outage was expected to be fixed. Then I mentioned that we'd had a number of issues in the last two months, which was when she started counting them and got to "nearly
10" (her words), although she said some were only a few seconds. We did have a 2-hour one, and other of about 5 minutes. During that one I'd got a little way into shutting the computers down when the volts came back on.
This whole sequence feels like it started a couple months ago with the early morning lightning strike that took out the router and the cordless phone base.
36 hours is our longest after an ice storm brought the lines down is several places snapping a number of poles in the process. Nice bit of compensation for that one.
Just ordinary portable camping gas lanterns. If you really want to use your heating oil I guess you could get a Tilly Lamp, uses a mantel like the gas lanterns but some what more messy to light and smelly.
They also claimed to have 472MW of battery backed storage capacity (although how many MWhr is unclear). It is reasonable to assume that it also came onstream pretty quickly.
From the time stamps Hornsea went offline within 230ms of the detection of a blue phase plasma short condition on the transmission line and the first Barford turbine went down within a second. That is nearly 1000MW down. It seems very likely that both were reacting to the lightning event. Barford was fairly close to the lightning strike.
That started the rot in terms of the frequency changing fast enough to cause self protection circuits to activate elsewhere. I think both went down essentially at the same time but Barford only dropped 244MW of output in around 1s whereas Hornsea dropped 737MW off in 0.1s.
And the transmission line had cleared its fault condition and restarted within twenty seconds which isn't at all bad.
I suspect the wind turbine grid tie converters at Hornsea were set to a hair trigger and responded to a transient in an unexpected way. East Anglia offshore was a lot closer to ground zero and survived unscathed.
The thing that seems to have tipped them over the edge was all the small scale stuff that also dropped off as the frequency dropped or as a result of the brief interuption on the transmission line. Presumably they will piece together a timeline of exactly which protections triggered and why. They imply on page 14 that there was something a bit dodgy about the transient response of Hornsea's main systems. See p14
Hornsea Wind Farm: "Following an initial review, adjustments to the wind farm configuration, and fine tuning its controls for responding to abnormal events, the wind farm is now operating robustly to such millisecond events."
The distinct implication here is that previously it was not. This and other key details are conveniently missing from the executive summary.
I'd tempted to chase that up in a few days time, or the next outage...
Had that with a insulator that was arcing over. Power did the off-on-off-on-off-on-stay off sequence then about an hour later would briefly come on, every 5 to 10 minutes. For one of these brief on's we noticed a buzzing and smoke from one of the insulators, rang the DNO. They passed the info the engineers who turned up saying they'd almost found it when the message came through.
Blooming lightning, this year two strikes have had a port on the load balancing router (that was connected to an ADSL modem), the POTS port on the N300 VOIP/DECT base station and vaporised something inside the ADSL filter.
I wonder if the strike caused an insulator (or more) to arc over and they are now starting to fail at operating voltages? The arc damaging the glazed insulator surface allowing the build up of muck in the track.
Always check your genny periodically, both for mechanical faults (seized bearings in the diesel generator) and electrical faults (eg overloading).
I used to work in a big 10-storey office block in Bracknell. One day the mains went off - a workman had driven a JCB through an underground high-voltage cable somewhere in the area. There was an immediate groan from the guy who looked after one of our servers because he knew what a bastard it was to get that computer working again after an unplanned shutdown. Within a few seconds, the building's emergency generator kicked in, with a hell of a roar and a lot of black diesel smoke - it was right under our department's window. But after about a minute there was an almighty bang and a bright flash of light. And then no more power for the rest of the day until the mains was restored.
I *think* the fault was found to be a combination of poor lubrication in the engine and/or generator, and a generator that had been specced when the building had a few mainframes, and since then everyone and his dog had their own PC, so the power requirements were a lot greater. After that they did periodic testing of the generator - publicised in advance so sensitive computers could be shutdown gracefully beforehand rather than having the rug pulled out from under their feet. Hopefully the genny was still tested with a reasonable approximation of a real-world load, and that the loss of those bastard-to-reboot servers didn't make the results too atypical.
It may well be worth complaining. We had a few power cuts over the course of the last year or so and when I contacted UK Power Networks they said that they were aware that one of our local cables was unreliable and they were trying to locate the exact position of the fault. Eventually they must have given up trying to find it, as over the last few weeks they have replaced a whole length of cable between sub-stations, digging up several local roads in the process. We've had no power cuts since, but I guess it's too short a time to be sure that they have fixed the problem.
a good many years ago, we used to suffer intermittent breaks, I complained and since we have 2 incoming phases I was swapped to the other one. But I know the breaks continued. The one day someone noticed the tarmac in the road was bubbling at afew places.. Investigation showed that when we had a new gas main some years previously, the mole making holes for the houshold gas supply had managed to scrape off the outer armour of the 3 phase feeder in a number of places. After heavy rain one phase started shorting to ground. The heat which was enough to boil the tarmac luckily didn't melt the gas pipe.
At least within the Electricity industry 'outage' has been used in the UK since the 1960's, but it is the term applied to the usually every other year total shutdown of large generating plant for maintenance on the power station itself.
Loss of supply is the usual term within the industry
Power cut the term for communicating with the public
Well those would have needed a lot more power, and usually a special power supply providing a much higher frequency too (the Univac 418 at the the London Hospital certainly did).
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