[HN Gopher] The Telechron master station clock was used to maint...
___________________________________________________________________
The Telechron master station clock was used to maintain power grid
frequency
Author : rbanffy
Score : 51 points
Date : 2024-03-01 15:24 UTC (7 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| micheljansen wrote:
| Interestingly, power grids also made a lot of clocks possible
| that relied on a fixed AC frequency.
| mbreese wrote:
| That's actually what the story was about. In order to have/sell
| a good AC grid-powered clock, it was necessary to have a
| consistent AC frequency. A consistent frequency was also
| necessary to have an interconnected grid. Solving one problem
| (the household clock) also made power grids possible.
| detourdog wrote:
| I have a 1931 model school built by the works progress
| administration. The school had a dedicated clock circuit one
| of about 5 electrical circuits. The clocks came from Standard
| Time Company of Springfield Mass. It has a paper tape that
| represents the bell schedule for the entire year. The clocks
| being on the same circuit kept them in sync. The paper tape
| rang the bells on the schedule.
| Mtinie wrote:
| "I have a 1931 model school built by the works progress
| administration."
|
| As in, you own one? If so, that's awesome! I'd be very
| interested in learning more.
| detourdog wrote:
| Yes. It's a 1931 school with a '54 edition. I have been
| working on turning each class room into a studio
| apartment.
|
| It has been really great experience. The historic design
| significance is really deep.
|
| Here is what is left to the architect that specialized in
| model schools made of re-enforced brick masonry.
|
| https://www.michiganmodern.org/modern-designers/warren-
| holme...
|
| The current building codes I think were fundamentally
| defined during this era of construction. The building is
| technical a Modernist building as it steel structure with
| brick veneer walls.
|
| The building was very original when I got it and I have
| tried to maintain that as much as possible. I have
| insulated based on guidance from Building Science
| Corporation. I'm in New England and we have been getting
| by using air sourced heat pumps. I have a 40kW solar
| array to offset energy costs and fiber to the building.
|
| https://www.icloud.com/sharedalbum/#B0Y5oqs3qnakFd
|
| The building is live/work and I'm hoping to attract HN
| like people to create a strong community.
| malchow wrote:
| The power grids (in the US) do not do a good job of keeping 60 Hz
| these days. More here:
|
| https://enphase.com/download/calculating-ac-line-voltage-ris...
|
| The more Enphase type inverters
| (https://enphase.com/download/iq8-and-iq8-microinverters-data...)
| that can be introduced to the grid, the closer we can get to
| stable voltages as in days of old.
| kube-system wrote:
| Is it actually worse or do we just have a different standard
| for "good job"?
|
| The AC clock on my oven definitely drifts by a couple minutes
| every once in a while, but it's a lot better than the
| mechanical clocks I remember as a kid. Yet it's still good
| enough that I've never seen my UPSes report anything other than
| 60.0hz
| zeroping wrote:
| That first link seems to talk about voltage swings, not
| frequency changes, doesn't it?
|
| I do understand that the loss of rotating interia in the grid
| generation mix is a concern long-term. (See concerns from a
| report like https://www.osti.gov/servlets/purl/1854457 ), but I
| hadn't seen any charts showing that we were less frequency
| stable than in decades past.
|
| I don't get how the latest inverter from Enphase is a specific
| solution. What does the IQ8 do to help grid stability? I'm
| legitimately curious. I know many inverters do some kind of
| frequency -control for curtailing power output, is that what
| you mean?
| MisterTea wrote:
| Where in the 47 pages of wire sizing does it say anything about
| time keeping? This reads like an Enphase ad.
|
| This is more strait forward albeit 20 years old already:
|
| http://leapsecond.com/pages/mains/
|
| http://www.leapsecond.com/ten/
| phone8675309 wrote:
| GP account posts a lot about Enovix and Enphase and really
| seems like a shill
| xattt wrote:
| Related, but this is a video about first sync of a refurbished
| unit at Bruce Nuclear Generating Facility.
|
| https://m.youtube.com/watch?v=Zw39gxIqfVU
|
| It's still interesting that despite all that tech, there needs to
| be a person watching the sync clock.
| T3OU-736 wrote:
| Watching this, a couple of questions came up in my mjnd:
|
| 1. Siemens rep physically touching things despite vibration
| sensors being in place - do they not trust the sensors? If they
| do not, how are they doing routine monitoring? Have someone sit
| atop the machine and feel for things 24/7? Or is that just the
| rep grandstanding for the cameras?
|
| 2. Time of grid sync only having hh:mm precision. Nitpick, but
| at 60hz, that is about 50s of imprecision.
|
| 3. The mentioned previous unsuccessful attempts - so went
| wrong? Dunno, I tend to learn more about systems from failure
| :)
| ooterness wrote:
| It costs nothing to check. Gauges are one thing, but physical
| senses are good for intuition. It's no different from a
| racecar driver knowing their engine is underperforming
| because it sounds different.
| j-bos wrote:
| > Siemens rep physically touching things despite vibration
| sensors being in place - do they not trust the sensors?
|
| Trust but verify?
| jabroni_salad wrote:
| The building I currently work in used to have clocks that
| were synchronized by the power grid. The power company would
| guarantee a number of cycles per day. While the precision
| isn't always there your clocks would never be permanently
| drifted and that was good enough.
|
| I haven't looked into it but the guy who sold me our current
| gps time receiver told me that power companies no longer
| offer a cycle guarantee.
| 01HNNWZ0MV43FF wrote:
| If it's the first time the equipment has spun up after the
| sensors were installed, maybe he's just validating the
| installation. Maybe they wouldn't be doing that 24/7, just
| every month or year, the same way I don't validate unit tests
| constantly, only when I write them and then occasionally
| after.
| ooterness wrote:
| The synchroscope is a very important gauge for any power plant:
|
| https://en.wikipedia.org/wiki/Synchroscope
|
| In short, every generator is also an electric motor. When you
| connect a generator/motor to the grid, it begins rotating in
| sync with every other generator/motor on the grid. The grid
| will supply any amount of power required to speed up or slow
| down as needed, to keep everything locked together.
|
| The initial synchronization process may be quite violent,
| depending on the size of the initial discrepancy.
|
| The synchroscope is the gauge that shows the phase and
| frequency difference between the generator and the grid. Before
| closing the switch, operators align everything as closely as
| possible to ensure a smooth transition.
| MadnessASAP wrote:
| We have some older AC-AC converters to convert 60Hz wall
| power to 400Hz aircraft power 3 phase. They use a motor
| coupled to a generator, about 100kW output. If we shut one
| off and then restart it before it's fully spun down the phase
| difference between the motor and the grid is enough to make
| this thing kick and jump a fair bit. I'd love to see what
| happens at 200+MW! From a distance of course. I imagine the
| structural damage would be rather spectacular.
| mjevans wrote:
| Strongly suspect some engineer included a 'weak' conductor
| somewhere as a sacrificial fuse. Wires tend to be way
| easier to replace than entire buildings. Just look at how
| violent aircraft jet engines are when they pop.
| 01HNNWZ0MV43FF wrote:
| Someone tested such a thing on a pretty big generator:
| https://www.youtube.com/watch?v=LM8kLaJ2NDU
|
| https://www.wired.com/story/how-30-lines-of-code-blew-
| up-27-...
|
| > Black chunks began to fly out of an access panel on the
| generator, which the researchers had left open to watch its
| internals. Inside, the black rubber grommet that linked the
| two halves of the generator's shaft was tearing itself
| apart.
|
| This was a proof-of-concept for a cyber attack on power
| infrastructure.
|
| They sent it malware that inverted the grid sync behavior
| from "Sync up, then connect, and if you de-sync,
| disconnect" to "If you are synced, disconnect, if you are
| desynced, reconnect"
|
| The Wired article is an advert for a book filled with
| pretty fluffy prose - At times reading like a romance
| novel...
| blibble wrote:
| here's a demo of it at a human understandable scale
|
| https://www.youtube.com/watch?v=sFohkp2aaU4
| trollied wrote:
| Similar, but a really small hydro plant:
| https://www.youtube.com/watch?v=xGQxSJmadm0
| 486sx33 wrote:
| I was inside Bruce A when it was completely mothballed. Crazy
| that's it's back online
|
| I was inside a Niagara hydro electric station in the 80s, they
| still had analog clocks on the wall for grid and station
|
| Eventually with enough renewables on the grid, sync gets a
| little tougher, so far so good :)
| Mistletoe wrote:
| The word This that was dropped in the title would really help it
| make sense.
| dang wrote:
| Maybe, but it's also a linkbait 'this'. As is sometimes the
| case, the photo caption has a more specific title, so I've put
| that up instead.
| md224 wrote:
| Why does HN automatically drop "This" in article titles?
| CamperBob2 wrote:
| So as not to signal mindless clickbait, I imagine.
| ooterness wrote:
| It took me a long time to understand a key reason the electric
| grid works at all: the rotational inertia of all the big, heavy
| generators in the system.
|
| As an example, imagine a frictionless generator with no load,
| spinning at 60 Hz. The rotating mass of the generator stores
| kinetic energy, and its windings are ready to convert that to
| electrical energy. Attaching an electrical load slows the
| rotation unless something is done to replenish that stored
| kinetic energy.
|
| On a larger scale, loads are switching on and off all the time.
| Power plant operators need time to react, because adjusting the
| throttle isn't instantaneous. A natural gas generator might take
| seconds to throttle up or down; adjusting a nuclear power plant
| could take a while. In the meantime, energy is drawn from the
| buffered kinetic energy of every generator on the grid. They are
| all rotating in sync because every generator is also a motor.
|
| The frequency of the grid is the signal everyone uses to know
| whether generation matches consumption, averaged over second or
| minutes or hours.
| throw0101d wrote:
| See perhaps "Grid frequency volatility in future low inertia
| scenarios: Challenges and mitigation options"
|
| *
| https://www.sciencedirect.com/science/article/abs/pii/S03062...
| datadrivenangel wrote:
| Synthetic Inertia and Frequency Control Ancillary Services
| will help resolve this issue.
| sandworm101 wrote:
| And water. Try to slow down a hydroelectric turbine, increase
| its load, and you are fighting thousands of tons of moving
| water flowing through a massive pipe. Any change will take at
| least the time equivalent to the speed of sound in water
| through the length of that pipe.
| Animats wrote:
| Here's someone doing exactly that, synchronizing a medium-
| sized hydroelectric generator to the grid.[1] The valve-to-
| turbine pipe delay isn't a big problem. This stuff is
| adjusted on the scale of tens of seconds. Opening the valve
| makes the whole reservoir slosh for a few minutes, and the
| operator had to wait that out before trying to achieve sync
| by hand.
|
| [1] https://www.youtube.com/watch?v=xGQxSJmadm0
| peterleiser wrote:
| Thank you posting this! Awesome video. As an aside, I went
| down the rabbit hole on this topic last year when I was
| considering building my own local grid composed of
| multiple, heterogeneous generators and solar. Instead, I
| ended up buying a pair of parallel generators and called it
| a day.
| wbl wrote:
| Nuclear can load follow very quickly: cooler water accelerates
| the reaction by moderating more and cranking up the coolant
| speed increases the heat delivered. The nucleonics issues are
| more over a daily shutdown or the like than quick load
| adjustments.
| anonporridge wrote:
| This is also why chemical batteries that can react in
| milliseconds are such useful buffer tech, even if they can't
| store more than a few hours of demand.
| kragen wrote:
| chemical batteries don't take _nearly_ that long to react!
| ls612 wrote:
| In a previous life I worked as an intern at a company making
| SCADA software and the like. The fact that they did this by
| hand, managing the grid and keeping it in balance, for 60-80
| years before any computer existed to help them, and it
| basically worked, boggles my mind.
| spazx wrote:
| And not a single mention of where he built the Telechron factory.
| The first and last, I believe, was built in Ashland, MA.
| Recently, they put up a nice commemorative light-up sign and lit
| up the old clock tower too.
| MarkusWandel wrote:
| "The adoption of digital clocks sealed the deal" (of clocks no
| longer counting power line cycles). But did it? My impression is
| that for decades, digital clock radios did that just that.
| sandworm101 wrote:
| They still do. See below how the European grid ran a little
| slow, causing all the oven clocks to fall behind. This was
| corrected by running the grid slightly faster, to move all the
| oven clocks forwards again.
|
| https://arstechnica.com/tech-policy/2018/04/european-grid-di...
|
| https://electronics.stackexchange.com/questions/360328/serbi...
| giva wrote:
| Here you can see the current grid time and frequency of the
| continental Europe grid:
|
| https://www.swissgrid.ch/en/home/operation/grid-data/current...
| phire wrote:
| This article is wrong, or at least the headline and intro is
| wrong.
|
| You don't need a precise time source to make power grids
| possible. You don't need any time source at all, as generator
| operators simply synchronise with the grid's current frequency
| (and phase) before throwing the switch that electrically connects
| the generator to the grid. And once the generators are connected,
| they are automatically locked to the exact same frequency and
| phase. It's not possible for them to fall out of phase without
| the electrical connection being broken (If you try to force a
| generator out of phase, it will draw more current trying to get
| back in phase and will eventually blow a fuse)
|
| For engineering reasons, it's useful to keep the frequency within
| a few percent of a standard, but for most purposes, it doesn't
| matter if the grid is running at 58Hz, 60Hz or 62Hz and you can
| achieve way more accuracy with crude mechanical governor. Many
| simpler backup generators use nothing more than a mechanical
| governor to maintain their frequency.
|
| The primary reason why power grids used accurate master clocks is
| actually the secondary reason that this article mentions:
| Automated time synchronisation.
|
| This predates the days of modern quartz clocks. It was possible
| to make very precise mechanical clocks (especially for navigation
| use), but they were impractical and too expensive for every day
| use. The average clock or pocket watch would gain or lose several
| minutes per day and required constant manual adjustment. Loud
| bells ringing each hour would allow a town or small city to keep
| the same time, but different towns would be out of sync with each
| other.
|
| There were various competing solutions at this time. Clocks would
| be synchronized over long distances with time signals transmitted
| over telegraph or radio. Paris actually had a network of
| pneumatic tubes that drove synchronised clocks driven with a
| pulse of air every minute:
| https://www.amusingplanet.com/2022/02/the-pneumatic-clocks-o...
|
| But the power grid neatly solved this problem.
|
| Not only did it distribute power, but it distributed a
| synchronised time signal across the entire nation. Your
| complicated mechanical wall clock could be replaced by a simple
| electric synchronous motor that drove the clock hands and it
| would keep perfect sync with every other clock on the same power
| grid.
|
| All you needed to make this useful was a single master clock that
| kept the power grid running at exactly 60Hz (well, it actually
| drifts as load varies, but they deliberately vary it so there are
| exactly 5184000 pulses per day).
|
| This time keeping service that power companies supplied as a
| secondary effect of their primary purpose was typically mandated
| by government regulations, as cheap and accurate synchronized
| time is a boost to the economy.
| jleahy wrote:
| That's not correct. The frequency provides an indication of how
| much power is being drawn. If the frequency is low then
| generators supply more power to bring it back to 60 Hz.
|
| If there was not a well known fixed frequency it would be
| impossible to evenly distribute load over power stations. All
| generators have a %load vs frequency delta curve built into
| them which is precisely calibrated.
| technothrasher wrote:
| Hey, cool! I just finished restoring a Telechron Master Type B
| clock, and here is a story about these Telechron master clocks on
| HN. It's very satisfying to watch the large hand bounce back and
| forth at zero when the mechanical movement and the electric rotor
| are perfectly in sync.
___________________________________________________________________
(page generated 2024-03-01 23:00 UTC)