Detecting/avoiding brownouts caused by accumulator discharge rate limit?

[torne]

My factories are almost always powered by the common setup with solar+accumulators in roughly the right ratio combined with backup power that's controlled by a SR latch that enables when the accumulator power runs low. This works fine most of the time, but if the factory's power needs grow too quickly compared to the amount of solar+accu power, it reaches a point where even when the accumulators have plenty of charge, the total discharge rate of the accumulators (300kW * number of accumulators) may not be enough to run the entire factory without brownouts. The backup power avoids complete power loss, but every time it turns off it goes back to a brownout state.

I've been trying to come up with a way to prevent or at least detect this without simply leaving the backup power permanently online, but haven't managed to make anything work the way I'd like. I've built a couple of variations of brownout detector that I've seen people suggest, but the combinator-based ones I've tried only work when the brownout is sufficiently severe (it seems like combinators work normally even if they only have ~80-90% power, and only start to slow down when power gets down lower?), and the belt/inserter based ones I've also had trouble getting to trigger reliably in similar conditions.

Can anyone recommend a solid design for a brownout detector that works even if the power satisfaction is high (but not 100%)? Or an entirely different way to solve the underlying problem?

Ultimately the issue is that if you have N accumulators (and ~1.19N solar panels for the optimal ratio), this can supply up to 0.05N megawatts without ever needing backup power (by the normal solar ratio calculations), but adding backup power with the common RS latch setup only reliably supports a peak consumption of 0.3N megawatts, and I keep not noticing that my factory actually peaks at more than that :/

Edit: also the assumption here is that the backup power IS sufficient to supply factory peak demand, otherwise you're stuck anyway

[zOldBulldog]

Try this. You should be able to choose the power level you want.

https://factorioprints.com/view/-LOOQbz6NZoOI4hjPCtl

I use it a bit differently than in your scenario but you should be able to find a way to adapt it:

- I typically connect all of my factories to the same power grid.
- I use this circuit to shut down factories - in order - as the power levels drop. The least important factories shut down at 90% of accumulator charge, the next at 80% and so on.
- Of course there is an alert (single beep plus text message) when a factory shuts down, so that you can run to add power.
- There are some rare marginal scenarios where you get a cycle of a factory powering down, the accumulator recharging quickly, then shut down again. You then get a series of alerts for the same factory. In any case the fix is simple, add a power switch you can turn off manually so that you can keep one of the factories off while you go build more power... you could even make it signal-based and simply place a constant combinator down wherever you are, wired to your power grid red/green wire.

[Xeorm]

I don't think there's any straightforward way since you can only check the charge level. You could measure the rate though using combinators. If the rate of depletion is the maximum of the system, then you're in a brownout scenario.

Seems like you could also do with adding more accumulators to act as simple backup power.

[torne]

Try this. You should be able to choose the power level you want.

Thanks, but that's functionally equivalent to the simple SR circuit I already use to control my backup power, which is also based on monitoring an accumulator's charge level. The situation that's a problem is when the accumulators are still quite full, but are unable to supply enough power for the current demand due to the discharge speed limit of 300kW per accumulator. I'm not trying to shut off part of the factory or anything - I want the factory to run at 100% all the time, and I have enough backup power to do this (big nuclear reactor). I'm just trying not to waste fuel by having the backup power active all the time, which I realise isn't really a major issue with kovarex/etc but it's the principle of the thing - if you let the backup power always be online then you practically may as well not bother building any accumulators at all as they'll never be used except in extremely sudden power spikes.

What normally happens with solar + accumulators + backup power when power demands get high is that eventually even during the day your solar panels + accumulators aren't enough to keep up, and your backup power starts turning on and off throughout the day as well as during the night. This isn't a problem in itself: it means you need more solar if you want to avoid using backup power but everything still works at 100% power so it doesn't slow/stop the factory. The issue is when the power demand gets high enough that you need more than 300kW * accumulator count, which is the most they can deliver: you'll be in a brownout condition with machines slowing down etc while the accumulators discharge, until they reach whatever point you've set to enable backup power activates. While the backup power runs, the factory will be back to full speed, but as soon as the accumulators charge up enough that the backup power turns off you go back to brownout.

I don't think there's any straightforward way since you can only check the charge level. You could measure the rate though using combinators. If the rate of depletion is the maximum of the system, then you're in a brownout scenario.

Ah, yes, that might work - the combinator setups I've been trying to use are based on the combinator itself changing its behaviour when it's low on power, which hasn't been sufficiently sensitive/reliable. Just calculating the discharge rate is pretty straightforward and would be able to tell me when I'm actually running the accumulators down at 300kW each, so I can at least trigger an alarm to let me know. I'm not sure this can be used to actually control the backup power though - I don't think you can measure the consumption the same simple way while the backup power is active, because the accumulator charge rate depends on *both* the factory power consumption and the backup power output, and the latter may not be constant.

Seems like you could also do with adding more accumulators to act as simple backup power.

Yep, slapping down more copies of my solar+accumulator blueprint will resolve the problem for now, but if the factory power consumption is only high enough to cause the problem during spikes it's hard to notice you are even in this situation and need to build more... and ultimately, if you're going to keep building more solar+accumulators whenever you need more power, I feel like you might as well just pave the world with them and not bother with any other sources of power at all, which also removes the problem

I just often find when I'm building a factory that I go through a phase where I'm building solar (rather than building more coal fueled boilers - I usually never build more than a single 1/20/40 boiler setup), and then later on when I have a reasonable nuclear reactor it feels like a waste to just run the reactor all night every night even when the accumulators would have been enough. If I can't come up with a good automated solution I guess I'll just leave the reactor connected full time and just stop building new accumulators, instead: building more solar still takes load off the reactor during the day and reduces fuel consumption, even with zero accumulators.

[DaleStan]

I don't think there's any straightforward way since you can only check the charge level. You could measure the rate though using combinators. If the rate of depletion is the maximum of the system, then you're in a brownout scenario.

I'm not sure this can be used to actually control the backup power though - I don't think you can measure the consumption the same simple way while the backup power is active, because the accumulator charge rate depends on *both* the factory power consumption and the backup power output, and the latter may not be constant.

I think you can measure backup power production by steam consumption. Make sure you have a big array of water tanks feeding your backup power, and turn off(!) their input when you turn on the backup power. Then measure rate of change of the water and steam levels, and use that to calculate power production, from gross steam consumption (gross steam production rate - rate of increase) and gross steam production (water consumption).

If the water level gets too low, sound an alarm and turn the water input back on.

For even more complicated-ness, use two (banks of) tanks. Fill one tank while draining the other, and switch back and forth between the tanks. Sound the alarm if both tanks are too low.


I don't know if the fluid system will cooperate with this, though.

[bobucles]

Inserters slow down during a brownout. You can measure full power by measuring inserter throughput. When the number is consistent, power is good. When the belt counter drops, there is a brownout.

[zOldBulldog]

TBH I didn't even know this was a problem before I started reading the thread.

I thought that if an accumulator used to measure power drops below X% the factories are still being powered at 100%... until the accumulator charge drops to 0% at which point brownouts begun.

This thread seems to indicate that brownouts can happen while accumulators still have charge. Can this be confirmed (and possibly explained) by players other than the OP?

@DEVs, MOD writers and Experts:

- If confirmed, we really need some RELIABLE method to at least get an alert when on a power grid the factories are consuming X% of what the power plants connected to the grid can produce.

- Whether that method is a blueprint, a mod or a new core feature does not matter... so long as it accomplishes the above.

- Elaborate explanations and excuses don't cut it.

A very simple solution that the DEVs could provide if they wanted to:

- Any power generating device has a max that it can generate, that max is known, so there is no excuse why there can't be a signal that reports it.

- The same goes for any power consuming device - it is known what is the max consumption can be and it can be reported through a signal.

- As the "generatable power" and "consumable power" signal can be added in the grid (at least if it has red/green wires) then a simple circuit could instantly tell us the % of potential consumption vs potential generation. When it reaches X% the circuit could ring an alert to remind us to add power generation.

- This would be *FAR* more reliable than the current accumulator based designs.

[Xeorm]

Ah, yes, that might work - the combinator setups I've been trying to use are based on the combinator itself changing its behaviour when it's low on power, which hasn't been sufficiently sensitive/reliable. Just calculating the discharge rate is pretty straightforward and would be able to tell me when I'm actually running the accumulators down at 300kW each, so I can at least trigger an alarm to let me know. I'm not sure this can be used to actually control the backup power though - I don't think you can measure the consumption the same simple way while the backup power is active, because the accumulator charge rate depends on *both* the factory power consumption and the backup power output, and the latter may not be constant.

Not going to be able to control it exactly, but could always bodge it. If it's triggered then have the backup power run for some amount of time. If it is relatively rare than having it go for 30-180 seconds would probably work too.

[Mmmmmmorten]

Power control and amounts seem to always be an issue for me as well.
Building a 4800 SPPM base and ramping up power as needed. When I test a new section - i.e. circuit plant (80 green - 15 red 2 blue + modueles) is sucks up insane amounts of energy. Just me steel plant (18 belts of steel out) has over 15.000 beacons and just on idle that is more power then my starter city use going full out.

My solution too this has been several (same as everyone else I think):
I combine Nuclear Power build (got 30) with solar panels (about 300.000 with 270.000 accumulators).
My first problem is brown-outs when testing stuff. Nuclear power needs power to run - water pumps need power, inserter for uranium fuel cell needs power. If I do lose power I most likely will have nuclear plant drop of totally. Now is has a huge steam storage capacity that actually prevents that.
And on daytime - nuclear and solar is more than enough to run it all (until I build to much). So I have 1 accumulator in town connected to an alarm that goes off if my accumulator charge goes below 75%. In building fase where I am now, that is an indicator that I need more power at night (either nuclear or more solar/accumulator footprint.

As mentioned, my solar trains and bots have placed 300.000 solar panels, but I'm now converting to Advanced solar panels (mod: Advanced Electric High Resolution). This leaves me with the 300.000 solar panel footprint but ramps up the power by 10 (advanced solar panel = 600 kW, advanced accumulator = 50 MJ capacity and 3 MW in-/output).

I have no other smart way to do it that I know about. The game is geared for using nuclear power before accumulator (since it's an always on power in it's basic setup). When no more nuclear power is available to fulfill needs it will use accumulator charge. And I guess you wan't your brown-out security after this if charge goes below a certain %?

Oh... I have all new builds for the 4800 SPPM on power-switch with the on/off button outside my Mall (cable in train network) so I do not have power issues now, but know that when I turn it on and run it all full out (as it should to produce my science packs) - my power needs will be insane..

Only when all is up and running full out will I see if I have enough.. As long as accumulator charge running full out does not fall below 40% I'm happy...
Will keep an eye on this forum for breaking news in power management.

Link to blueprint of my Nuclear power plant 8 cores with storage tanks and smarts for power on/off is here.

/old dude

[quyxkh]

The 25/21 panel/acc ratio is good for a power supply that exactly matches a constant demand, but a base with exactly enough panels to cover its needs can't grow. If you've got 33% excess panel capacity you've overbuilt your accumulators by 33%, you only need 14 of those 21.

So you're overbuilding anyway, deal with it. Accumulators are dirt cheap, it's not at all unreasonable to build them in order-of-magnitude chunks, 100 at a time, 1000 at a time, just skip 10000 and build 100000 (really, sqrt(100000)~316.23, 316/9<36, so 36×36 substations' worth at 80/substation is 103680 accumulators, building those takes about ten minutes' supply in a KSPM-class base).

That gives you lots of advance notice when you're getting near time-to-build-more-power time, and you never ever have to worry about discharge-rate throttling.

[torne]

TBH I didn't even know this was a problem before I started reading the thread.

I thought that if an accumulator used to measure power drops below X% the factories are still being powered at 100%... until the accumulator charge drops to 0% at which point brownouts begun.

This thread seems to indicate that brownouts can happen while accumulators still have charge. Can this be confirmed (and possibly explained) by players other than the OP?

https://wiki.factorio.com/Accumulator mentions in multiple places that the maximum output/discharge rate of an accumulator is 300kW, so yes, if you try to use more than 300kW * number of accumulators and you don't have any other power sources currently active you will be in a brownout state. When your accumulators get to 0% that's a full blackout

Inserters slow down during a brownout. You can measure full power by measuring inserter throughput. When the number is consistent, power is good. When the belt counter drops, there is a brownout.

Yes, I mentioned this in my original post: I've copied a couple of peoples' designs for this and also tried to come up with my own and have not found a way that reliably detects "small" brownouts, e.g. when over 90% of the required power is available but less than 100%. If there's a design you know of that does, I'd love to see a picture/blueprint for it.

Not going to be able to control it exactly, but could always bodge it. If it's triggered then have the backup power run for some amount of time. If it is relatively rare than having it go for 30-180 seconds would probably work too.

Yeah if it's just infrequent spikes that would work pretty well. Could also detect it triggering "too often" and set off an alarm.

I have no other smart way to do it that I know about. The game is geared for using nuclear power before accumulator (since it's an always on power in it's basic setup). When no more nuclear power is available to fulfill needs it will use accumulator charge. And I guess you wan't your brown-out security after this if charge goes below a certain %?

Yeah the issue is the relative power priority of steam turbines vs accumulators - there are mods which change the priority or make alternative versions of the buildings available with different priorities and that would work for my case with some accompanying circuit logic, but my current game is vanilla. However my problem is not accumulator charge percentage (I already control my backup power based on that), it's just the discharge rate limit, which applies as soon as you are using any accumulator charge at all - turning on backup power when accumulators drop below 100% would be basically the same as having it run all the time.

The 25/21 panel/acc ratio is good for a power supply that exactly matches a constant demand, but a base with exactly enough panels to cover its needs can't grow. If you've got 33% excess panel capacity you've overbuilt your accumulators by 33%, you only need 14 of those 21.

So you're overbuilding anyway, deal with it. Accumulators are dirt cheap, it's not at all unreasonable to build them in order-of-magnitude chunks, 100 at a time, 1000 at a time, just skip 10000 and build 100000 (really, sqrt(100000)~316.23, 316/9<36, so 36×36 substations' worth at 80/substation is 103680 accumulators, building those takes about ten minutes' supply in a KSPM-class base).

That gives you lots of advance notice when you're getting near time-to-build-more-power time, and you never ever have to worry about discharge-rate throttling.

You're missing the point - yes, building more accumulators means the limit will be higher of course, but that's not how I want to play: I'm not trying to build a solar powered base because I don't find it that interesting. My base is powered by a nuclear reactor, and it has plenty of spare capacity for growth. What I'm trying to do is avoid having all the accumulators I *already* built before the reactor go to waste. The solar panels are always useful since even if you never build any more of them they take load off your other power generation during the day and thus save you some fuel, but the accumulators become almost entirely useless. I rarely dismantle anything in my base - when my early game stuff is not able to be expanded any more (because I need to redesign to use modules/beacons, for example) I just leave it there and either repurpose it to something else or just let it continue adding its output even if it's tiny compared to things I built later.

I was just wondering if there was a neat way to make this power configuration work that I was missing, and several people have suggested some interesting ideas I'm going to experiment with; I don't need people to explain how to avoid the problem entirely, I'm interested in *solving* it, with some fiddly complex trickery that will be fun to figure out and will turn out to have yet another different problem after another forty hours, because that's what I personally enjoy

[quyxkh]

You're missing the point - […] I don't need people to explain how to avoid the problem entirely, I'm interested in *solving* it, with some fiddly complex trickery that will be fun to figure out and will turn out to have yet another different problem after another forty hours, because that's what I personally enjoy

Heh. Yeah, probably. But: accumulators on full discharge will deplete in 5000/300=16⅔ seconds, which happens to be exactly 1000 ticks. So if you ever see the accumulator charge dropping 1% per ten ticks, you're at max capacity, and you can get as cute as you want with watching the tick count between accumulator charge signal changes. Circuitry to track the minimum time between charge decreases since the last charge increase should be pretty compact.

[torne]

Heh. Yeah, probably. But: accumulators on full discharge will deplete in 5000/300=16⅔ seconds, which happens to be exactly 1000 ticks. So if you ever see the accumulator charge dropping 1% per ten ticks, you're at max capacity, and you can get as cute as you want with watching the tick count between accumulator charge signal changes. Circuitry to track the minimum time between charge decreases since the last charge increase should be pretty compact.

Yeah that's what Xeorm suggested above, I'm gonna try that when I get the time. That should work for triggering an alarm and/or turning on other power sources, but it doesn't directly give you a way to know when it's okay to turn other power sources off again (that will require more steps which we discussed a bit above too, but seems much fiddlier)

[Serenity]

Nuclear power needs power to run - water pumps need power, inserter for uranium fuel cell needs power. If I do lose power I most likely will have nuclear plant drop of totally.

Simply put that stuff on a separate grid run by it's own solar panels. Pumps and inserters don't use much. And if you use bots to transport the fuel cells they don't need much charge either. You can easily power that with a few panels

I have no other smart way to do it that I know about. The game is geared for using nuclear power before accumulator

You can put pumps between your steam tanks and the turbines and only activate them if the accumulator charge drops too low

[quyxkh]

The way I deal with this in my nuclear base is to go the other way around: I use an accumulator-charge-driven R-S latch on the entire science production complex, when the charge hits 5% science production shuts down, at 95% it starts up again. The nuclear plants never shut off, nuc fuel's literally too cheap to meter (also true irl), I guess you could really grossly overbuild nuc power and only take the UPS hit like 10% of the time, running everything off a ridiculous accumulator bank. Hmmm. I think I'm serious here. I like that idea. 30 GW for an hour is 648000 accumulators, that's not so ridiculous, is it?

[Mmmmmmorten]

when the charge hits 5% science production shuts down

My policy for Factorio is that nothing should ever be shut down due to power issues. I do that now when building the mega-base, but when all is up - it should run flat out all the time. So my policy is more power every time...

30 GW for an hour is 648000 accumulators, that's not so ridiculous, is it?

Nope.. had about 1 million solar panels on my last build with 850.000 accumulators. But it takes up a LOT of space!
So as I mentioned I'm upgrading my current 300.000 to Advanced versions (mod:
Advanced Electric High Resolution) that basically are 10 times stronger and will be the same as having 3.000.000 solar panels and 2.700.000 accumulators. Think that should do it as far as power is concerned...

Costs a s%#tload to build, but I get the power I need (and then some) on a much smaller footprint!

/old dude

[Mmmmmmorten]

Simply put that stuff on a separate grid run by it's own solar panels. Pumps and inserters don't use much. And if you use bots to transport the fuel cells they don't need much charge either. You can easily power that with a few panels

You can put pumps between your steam tanks and the turbines and only activate them if the accumulator charge drops too low

Yes that might work.. or it will when I think about it... but as you see from my last post... I tend to solve power issues with just having a LOT of it

Right now I have 3 TJ accumulator charge and it's growing with every solar train delivery. Guessing my end power need will be in the 50-60 GW range, but not sure how many beacons I end up with in all the Science builds... Not done all the math for the builds yet

/old dude

[quyxkh]

My policy for Factorio is that nothing should ever be shut down due to power issues.

There's my favorite word, "should"

Yah, if you have to shut something down you've been inattentive, that's respectable. It's where I started, I "should" have built more power long before that happens. Still, it feels good to have some control over the consequences, just in case, and now I kinda like watching it happen

[Mmmmmmorten]

Still, it feels good to have some control over the consequences, just in case, and now I kinda like watching it happen

Ahhhh... Now that is something completely different! I build power extreme just to be safe... Does not mean I will not have brown-out security or SR-latch control in other parts - you know - JUST TO SEE IF I CAN DO IT!

Two parts too Factorio:
Getting the math right so everything runs perfectly smooth as a baby's bottom...
...and, the let's see if this works or if I can make it do something brilliantly awesome? (well, in my eyes)
Both builds are, imo, what makes Factorio great...

/old dude

[Mmmmmmorten]

As I mentioned.. I do go big on power.. and since I just installed the Advanced Electric High Resolution I needed to upgrade all my old solar panels and accumulators to the next version - "Advanced" which is 10 x more powerful than the vanilla version.

MAD Solar plant small.jpg (16.62 KiB) Viewed 8150 times

My solar panel and accumulator plant

My new plant

All this just to build solar panels and accumulators (and nothing else).

Whooping 3,5k beacons and 1k smelters just for making upgraded solar panels and accumulators. (All builds except copper and iron is with 12 beacons)

Since I needed the oil refinery for a lot of batteries I doubled my green circuit plants - through in some plastic and made some red circuits too.
So when my solar panels are all upgraded to Advanced (10x power) I can upgrade again to Elite (10 x 10 power) as the plant is set up for it.
It will take a loooong time to do as 1 Elite needs 10 Advanced whom need 10 normal.. so basically make 1000 solar panels or accumulators for 1 x of the Elite version. So - you need a lot of mats - and I really had to get it out of my mall as it sucked up all my steel and green circuits. Well, up and running now and my solar train takes a trip with upgrades several times per hour so I can see my power increase.

/old dude