Smart Transformer - 20kW with UPS

[daave]

Here's something I've been playing around with - an alternative power grid with local transformers that can pull up to 20kW with Heavi-Watt wire instead of 4k or 1k with transformers.

Background:
All power generators are connected to a mainline, which is a power wire -- normal, not heavi-watt -- and an automation wire. All local power is connected via a "Smart Transformer" which connects to the mainline while charging, and disconnects from the mainline while discharging. Since no buildings are ever drawing power from the mainline, there is no worry about overload damage there.

The local circuit then draws power directly from the batteries.  The circuit can take the full load that the wire is capable of.  Up to 20kW with Heavi Watt.

The Smart Transformer basically looks like this (I removed connection to automation mainline for simplicity - see below for that). The battery on the right is the primary and the one the left is the auxiliary. The primary is set to send a signal when it is at a low (eg 10%) capacity and the auxiliary is set to a high (eg 90%).

Power & automation view:

Spoiler

 

The basic automation logic is:

If the primary is not low:
- charge the auxiliary until (near) full, and then disconnect from mainline and wait.

If the primary is low:
- disconnect primary from the load
- connect primary to the mainline for charging
- disconnect auxiliary from mainline (if connected)
- connect auxiliary to load

More details on the logic here:

Spoiler

I know the logic to this is really simple, but here it is anyways to help you build it from scratch.

There 2 signals coming from the batteries:
PRIMARY - Primary battery low. < 10%
AUX- Auxiliary battery charged > 90%

And there are 4 power shutoffs :
Primary-In: PRIMARY
Primary-Out: NOT PRIMARY

Aux-In: AUX AND (NOT PRIMARY) - equivalently (NOT AUX) OR PRIMARY
Aux-Out:PRIMARY

It's pretty straight-forward.  The only quirk is the Aux-In, because the signal indicates when the battery should STOP charging, which isn't typically how we use smart batteries.  It's saying: always discharge if the primary is offline.  Otherwise, charge until nearly full, then disconnect from the mainline and wait.

Technically, you can leave the battery at 99 or 100, but the constant BEEP BEEP BEEP will drive you nuts =]
 

 

The part that is missing in the above is connecting to the automation on the mainline, which you can either do with an OR Gate or a FILTER gate.

The end product looks like this (automation view).

Spoiler

In the above example I've used heavi watt wire which can pull its entire 20kW load, but you can use whatever type of wire suits you and your Dupes.

As long as you have enough power generators to cover your needs, this transformer will deliver uninterrupted power to the local circuit. 

Benefits:
- use whatever wire is most appropriate for the local needs
- single automation request for power - additional logic can be added to prioritize generators
- low decor penalty - mainline is normal wire
- simplified power grid

Issues:
- not possible to store power outside of the transformer (batteries don't charge other batteries)
-- this means, you have to store power resources (hydrogen ,gas) when the are available, rather than converting that to power and storing the power in batteries.
- may need redundant backup at generators for rebooting the system in case of catastrophic power failure.
- the auxiliary battery tries to stay full, which generates unnecessary heat. I tried an alternative design where the auxiliary remained at 0 until the primary started getting low, but the logic got too complicated to be a worthwhile build.
- bigger footprint than transformer

[Saturnus]

The switched battery supply is an old concept of the forum from way back before smart batteries even existed. But it's good to have it refreshed from time to time.

Note that because of the NOT gate there is a small delay where there is no power. This can lead to failures. Avoid it by having a 0.1 buffer gate between the right side battery output and the top right power switch.

[daave]

45 minutes ago, Saturnus said:

The switched battery supply is an old concept of the forum from way back before smart batteries even existed. But it's good to have it refreshed from time to time.

Note that because of the NOT gate there is a small delay where there is no power. This can lead to failures. Avoid it by having a 0.1 buffer gate between the right side battery output and the top right power switch.

My original design was like you describe, where the AUX was signalled to start draining a few seconds before the primary switched off.  It seems that in this design, since the primary battery is not signalling on 0, the power remains consistent.    But I will test a bit more to be sure.  There can also be a hiccup when using filter gates instead of OR gates to connect to the mainline, but again this seems to be OK when both batteries have some juice when they are swapped. 

[Saturnus]

Btw, here's the first version I made a few minutes after the automation upgrade preview came out November 2nd 2017 and gave us logic gates to use. I wasn't aware of the 0.1s delay built into the NOT gate either at the time.

I still use them, in the smart battery version, to power conveyor systems and other places where you can have great momentary power surges but the average power consumption is negligible. Or to have backbone power connections without using heavi-watt wires. A conductive wire can pass 100s of KWs using this technique.

[crypticorb]

This seems like a useful concept, but I'm trying to think of a part of normal gameplay where it would be more useful than a simple transformer with a cutoff signaled by a single smart battery?

I use these in my base all the time, either in dual transformers for transferring 2kW across long distance, or the exact design shown above for <2kW circuits in my base.