Analog Circuits - Advanced power systems

[Tev]

I liked this design (no silly inserters or too-smart-for-me combinators), so I implemented in my tiny 1GW factory. It works very well, but you might be surprised by its behavior.

So when your accu filter runs out of power your steam engines will start. Periodically.

backupfun2.jpg (100.09 KiB) Viewed 7835 times

(I have some steam engines running in main grid)
I expected there would be would be some hiccups during start due to way it starts, but this periodicity surprised me. What surprised me even more was how (I guess after filling backup engines with water after empty start) their production flattens . . . only to fall off a cliff later (I guess enough accus were recharged?).

backupfun3.jpg (112.31 KiB) Viewed 7835 times

System apparently handles that fine (huge accu farms help, as always), but you kind of expect backup power to be reliable . . . not crazy drunk.

Questions for those who have more experience with this design:
1) There is apparently tradeoff between number of accus in filter and energy level left in all your accus that triggers backup engines. Anyone has any numbers or rules of thumb?
2) Are there any problems with the start-stop nature of the backup power plant? I can't think of any, but it would be expensive to discover them when 2/3 of my defences shut down.
3) Any blueprints for scaling this design up? I'd like some inspiration how to tile it well.

Anyway I like this system a lot, it's fun to play around with. Thanks MadZuri!
Going to do more tests now

[MadZuri]

Can you scale it up? Well, yes, simply use the version shown earlier, with 2 tanks, 2 output pumps, 14 boilers and 10 steam engines. It doesn't need the constantly powered input pumps, as an offshore pump = 2 small pumps. That can control and supply up to 170 pumps (85 lines of 14/10). I don't have a quick equation for the response curve's relation to number of filter accumulators, sadly. The only problem I've had is not having enough steam engines total in the main grid. If you have more than one set of these, just have each one with a different number of filter accumulators so that it kicks on in stages instead of turning the entire beast on and off with each swing.

I have yet to find a better backup power design, TBH. The behavior doesn't surprise me at all. It's power seeking with negative feedback. The sine waves are evidence of self-stabilization behavior. I noticed that not only is it seeking equilibrium, but it is "smoothing out" the power demand from the laser defenses. Also, lol at "tiny 1GW factory".

[Tev]

Ooops I forgot you posted compact verion of your design - it's really nice, much better than kludge I made However when I played around with it I found really weird behavior:

BugQuestionMark.jpg (319.87 KiB) Viewed 7807 times

As you can see, I tried replacing first tank with pipe (2 tiles saved! ), but apparently it doesn't work. Except for the "long" version. I tried placing tank back (worked again) and placed pipe again - both versions behaved the same as in the screenshot (I tried it twice for both). Just as I started to think I understand fluid mechanics :/

Filter accus: I tried 4 accus per 5 steam engines (powering bootstrap pumps) and with overall bank of ~110GJ it kicked in when I had around 25% left in all accus . . . I'm now testing different ratio, will post results after.

And 1GW is tiny, I aim much higher

[MadZuri]

I'll try to help you figure what's causing that leakage flow. There are two reasons that I can think of.

The first is flow direction. Fluids flow left and up first, then right and down. Orientation matters. Yes, it's a lot like redstone in Minecraft. A simple solution is to disconnect the underground pipes, replace the tank, and let it completely fill with cold water before replacing those pipes.

The other is insufficient power draw. If the steam engines aren't maxed out, they won't consume max water and the entire system slowly warms up through leakage flow, amplified since you only have one tank.

Let me know of your findings either way.

[tolomea]

Steam engines behave oddly in small systems like that. They will actually consume less than 6 water/s if they are operating under max available capacity.

What happens is that steam engines will use the full 6 water/s if the water is not fully heated (to pull in hotter water), but if the water is already at max temp it will only consume what it needs based on power demand.

If that's accurate then could you fix all leakage / dummy load issues by leaving out one of the boilers so it never achieves max temp?

[vanatteveldt]

I tried to copy the setup from this thread. This is the first time I'm using large-scale solar+accu, so it's quite possible I'm doing something stupid

This is my switch and backup engines:

design

The gun turrets are connected to the main grid, and connected to the switch pumps via 4 accus. The 10 engines in the switch are connected to the pumps of the backup engines, and the backup engines are connected to the main grid again.

This is the power output/consumption over a day/night cycle:

consumption

What I dont understand is why the steam engines go online right away as soon as power drops, while there is still charge in the accus. I would have hoped/expected the steam to take over from the accus (since I have too few to fully power the base). did I miss something? Or should this become normal as soon as I add more solar+accu plants?

[DaveMcW]

You don't have enough solar panels to fully charge your accumulators.

[vanatteveldt]

Yes, that is probably the case - but why does the backup then kick in before the accumulators are 'dry'?

(which actually suggests that I can build the panels in the new plants first, and only add the accus later, I didn't think of that!)

Edit: worked like a charm. I plunked down a couple hundred extra solars without accus (darn expensive batteries ), so now the whole accu bank is fully charged at 10:00 in the morning, which I guess is a bit overkill, but at least the system seems to work:

power

One thing I don't understand / that interests me is how the steam backup starts up for a little while right before the accus kick in, and then again at the end (even though there was 1GJ accu capacity left or so?

Edit2: the next cycle, the steam did not kick in at the beginning of the night, but still kicked in at the end (while there was still quite a bit of accu charge left)

power

[DaveMcW]

4 accumulators might not be enough to run the pumps all night, try 6.

[MadZuri]

DaveMcW is, of course, right. It is still a good idea to maintain a ratio of 0.84 (or higher) accumulators per solar. Feel free to experiment a bit with the accumulator filter part. The easiest solution is to add more accumulators, but you might want to try to put a single solar panel in the isolated network with the small pumps. The pumps will power on when the rate of charging from the main base solar exceeds the drain from the pumps, which is also why you see the negative feedback cycles as it turns off every morning.

[SantaClauss]

Hi ho !!

I don't understand this system, it does not work for me...

If I understand right, this system would not start making electricity until the pumps lacks of electricity by the accu, right ?

I can't manage to make it work. I tried working from left to right, from bottom to top ( cause I read that the liquid behave differently ) but can't manage to get it to work.

As soon as my main grid accus start losing energy, the steammachines gets filled with hot water and start pouring out energy.

What am I missing o_O ?

[MadZuri]

It is difficult to help without additional information. A screenshot of the setup, as well as a 10 minute view of the power graph, would really help. I'm willing to bet that there are extra power pole connections somewhere. They need to be independent networks, and you can remove wire from poles by shift-clicking and manually wiring them with copper cabling... or you have too many boilers, or the input pump is losing power, or just about anything... I can't tell from the description what is wrong.

[SantaClauss]

Here's the setup how I am.


https://www.dropbox.com/s/i1as76qs6j75r ... p.png?dl=0
As soon as my main grid accus start losing power, even if they have enough to last the night, the steam machines that have water with temperature 18 in it start pulling all the water from boilers to start working. And while they are not working, the tanks fill up with water up to 25++ degrees.


https://www.dropbox.com/s/9ejwuq06fs3hj ... n.png?dl=0

Thank you.

Edit : For some reason I seem to have issues with the img tag, maybe firsts posts cant posts img ?

[MadZuri]

Oh, you are doing the combined setup. That one actually doesn't work. The reason it doesn't work is because the steam engines aren't always maxed out. They will consume less than max water, leak by the boilers, and heat up the tanks. Also, dropbox is a terrible site to use for pictures, stick to imgur or local data.

[SantaClauss]

Hi,
I've been able to make it work now, the first design.

Thanks for this it seems very nice, the last one I was using was including belt and stuff, which was more complicated and less reliant.

I was really trying hard the combined method and thought it would work!

Thanks again !