We've had a blackout! - Page 1
Forum section: electronics / general

author: Neper
author_rank: Frequent Contributor
timestamp: June 11, 2022, 02:36:27 pm
content: The first in two years and all of 1/5 second.My VOIP telephone crashed and so did one of our computers. All the rest was unaffected.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 11, 2022, 02:44:26 pm
content: Where is here and exactly why is this newsworthy?

author: thinkfat
author_rank: Unknown
timestamp: June 11, 2022, 02:46:49 pm
content: Quote from: Stray Electron on June 11, 2022, 02:44:26 pm"Here" is, I guess, Germany. And we "never" have blackouts. But a 1/5th second grid drop is not a blackout anyway.Nothing to see here, move along, move along.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: June 11, 2022, 02:49:28 pm
content: Seems to have happend in Germany whereblackouts are extremely rare.The last blackout I experienced was due to craneship hitting the high voltage lines running across the water.There even exist some pics of this event. Quite a bang.

author: JohanH
author_rank: Frequent Contributor
timestamp: June 11, 2022, 05:40:14 pm
content: I think it's a couple of years since we had one, too. Very rare.

author: james_s
author_rank: Super Contributor
timestamp: June 11, 2022, 06:03:11 pm
content: Up here in the rainy and heavily forested northwest this sort of sub-second power cut happens dozens of times a year, the UPS sitting near me reads 30 events since I installed it in December. A winter storm will typically bring one or two 10 second outages, the interval of an automatic recloser turning the circuit back on after a tree limb falls on a line. I'm right on the edge of the downtown area so lengthy outages are rare, but there are typically one or two a year lasting from an hour or so to several hours from trees falling over. They can fall on overhead lines and the roots can tear up underground lines. In rural areas it's common to have outages of several days to a week or more when a big storm rolls through. Most rural people have backup generators these days.

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 11, 2022, 06:03:53 pm
content: "Micro" grid drops are nothing unusual depending on where you live. As said above, this is not a blackout.And if you are surprised because this never happens in your area, consider yourself very lucky. It was extremely rare in my previous location, but in my current area, it happens more frequently. Maybe once a month on average. I have an UPS for my critical equipment.

author: RoGeorge
author_rank: Super Contributor
timestamp: June 11, 2022, 06:26:42 pm
content: A blackout is called when a large area remains without powered for much longer periods of time. At less than a second, I'd call that a power surge.At less than a second, you probably witnessed a successful auto-reclosing event.In every power distribution stations there are automated protections at the end of the lines, and they can talk with each other. These are, briefly said, devices monitoring the voltage and current (and thus the impedance) on the ends of the power transmission lines. They can detect many types of failures, distance to the defect, etc. and engage different protection mechanisms accordingly.One of those mechanisms is to trip the power for a fraction of a second only, then to automatically try to reconnect the line to power again, in the hope that maybe it was just a bird that got pulverized by the electric arc, or maybe a lightning strike, and the circuit is now good again. That's the auto-reclosing protection:https://instrumentationtools.com/auto-reclosing/https://library.e.abb.com/public/d9a7af4fb84394e8c125754d003393dc/RK85-201E_en_Auto-reclosing.pdf

author: JohanH
author_rank: Frequent Contributor
timestamp: June 11, 2022, 06:35:37 pm
content: The conditions changed after they introduced laws in 2013 (there's our "babysitting" government again) so that electrical companies have to pay compensation if we have a blackout for 12 hours and more. But some companies pay some compensation even for less hours. Electrical companies are burying power lines in many places, because it makes it cheaper for them. We've had underground power lines to our home for more than ten years; this is a village center in a quite rural area.

author: tom66
author_rank: Super Contributor
timestamp: June 11, 2022, 06:45:35 pm
content: Buried power is also common because it avoids the need to pay landowners, who can often demand significant sums for power lines travelling over their property. In the past, there were even ambulance-chasing style lawyers who would sue the power company if a pylon or power line was adjacent to your property (the thought being it devalued your property - despite the fact that you probably owned the property well after it went up)The disadvantage is the majority of these lines are under the road and so therefore any maintenance requires roadworks which is super popular with everyone.

author: JohanH
author_rank: Frequent Contributor
timestamp: June 11, 2022, 06:48:24 pm
content: Quote from: RoGeorge on June 11, 2022, 06:26:42 pmThat's an old manual.But principle is the same today. Modern relays are digital, e.g. ABB 615-series and 640-series protection relays. There's even a centralized protection unit now, which is very high tech:https://new.abb.com/medium-voltage/digital-substations/campaigns/smart-substation-control-and-protection-ssc600This is basically an embedded PC with all protection functions running in software. I think this is unique product so far. They tried this already in the 90's, but PCs were not fast enough at that time.

author: tooki
author_rank: Super Contributor
timestamp: June 11, 2022, 07:10:02 pm
content: Quote from: RoGeorge on June 11, 2022, 06:26:42 pmA surge is the polar opposite of an outage: it’s when voltage briefly goes much toohigh(voltage transient).Some terms for brief outages I found on power companies’ sites are “momentary outages”, “momentary interruptions”, and “short duration interruptions”.

author: james_s
author_rank: Super Contributor
timestamp: June 11, 2022, 07:44:08 pm
content: Quote from: RoGeorge on June 11, 2022, 06:26:42 pmThe auto reclosers here typically trip open for about 10 seconds, then they make one attempt to close the circuit, and if the fault remains they lock out. It creates the somewhat annoying situation where the power goes out for just long enough to mess up all the clocks and reboot anything not on a UPS, but it's better than the old days when a fallen branch would just blow a fuse and the power would be out until somebody reported it and the utility would come out and fix it.

author: jogri
author_rank: Frequent Contributor
timestamp: June 11, 2022, 08:41:18 pm
content: Quote from: Messtechniker on June 11, 2022, 02:49:28 pmYeah, about that... Maybe rare in big cities, but in my town (~10k inhabitants, so not some small remote village) i have roughly one total blackout per year that lasts from 30 minutes to 12 hours and a couple of brownouts/short disruptions that last a few seconds every few months. And those blackouts are usually at night so it's not load shedding due to high demand. Just a really shitty power grid at work that should've been rebuilt half a century ago but no one could be bothered to do that (it costs money, you know).

author: RoGeorge
author_rank: Super Contributor
timestamp: June 11, 2022, 08:51:15 pm
content: Quote from: tooki on June 11, 2022, 07:10:02 pmMy bad, sorry, I didn't know the correct En translation. In Ro the most used is "voltage drop" (can be drop to 0V or drop to lower than nominal), while when it's for more than a couple of seconds the popular term is "the current has been taken".Quote from: james_s on June 11, 2022, 07:44:08 pmAbout the 10 seconds wait before reclosing, I'm an electronist by profession, not electrician, didn't even know it can be that long, thanks for mentioning that.It happens that I know about line protections only because we were implementing SCADA systems in a few power distribution stations here, in Romania. I remember very fast reclosures times (during the acceptance test), less than a second. Or maybe it's yet another mistranslation of mine (in Ro it's RAR, standing for Reanclansare Automata Rapida, and meaning Fast Auto Reclose)?Googled and found this classification (in a Ro link)- ultrafast, tRAR=0.1-0.5s ;- fast, tRAR=0.5-1.5s;- slow, tRAR>1.5s; which I didn't know before

author: AndyBeez
author_rank: Frequent Contributor
timestamp: June 11, 2022, 08:57:51 pm
content: Willkommen in der neuen europäischen RealitätWelcome to the new european reality. Before the winter, and prices go stupid high, buy yourself a good quality UPS and some USB power banks. It's what usdigital preppersare doing in the UK.

author: PaulAm
author_rank: Frequent Contributor
timestamp: June 11, 2022, 09:00:12 pm
content: I'm in a rural area with parts of the distribution system about 100 years old. I typically have one or two major (>1 day) outages a year. Last year I had a 3 day outage after a storm. This is despite paying some of the highest electric rates in the US and having to listen to the local utilitiy's drivel about their reliability and dedication to going "green". There's a misconception that the utilities exist to produce power; that is only an incidental byproduct of their real purpose which is to make money in a legal monopoly. Maybe it's better in your country.I have a large UPS for my systems and a backup generator to run the house with a 30 day fuel supply. Eventually I'll be offgrid with solar and possibly wind + storage and not have to deal with the utilities at all.