Does anyone have a way to simulate a current transformer (CT?)

[Bryan]

I've been tasked with coming up with a way to simulate the output of a Current Transformer (CT).  Basically, a way to generate a 0-5A AC signal that can be controlled via automation to simulate a total of 15 CTs (simulation of five 3-phase lines). 

The option of using 15 programmable AC Current sources is currently being kicked around, but space and cost may raise some eyebrows here.  Not being an EE myself, I'm having difficulty coming up with a solution.

Does anyone have any ideas that they could toss my way?

Thanks!

[Tim_S]

This sounds like an application where could use a common bus drive (which is just a big AC->DC power supply feeding other big DC->AC power supplies). I don't think anyone makes something down in that low of a current range (typically think starting around 400A). This might save space and be lower material cost, but could be very expensive in development.

[Gribo]

You want 5 3-phase sources, not 15 single phase sources, or better yet, a single 3 phase source and some way to switch it to all loads. Here is one lab source:

http://www.chromausa.com/product/3-phase-programmable-ac-source-61700/

[Bryan]

We've simulated a generated 0-150VAC 3-phase source before with a NI-6733 and amplifiers, then shifting the phase of each channel to 0°, 120° and 240° respectively.  Due to the number of 3-phase signals we were generating to a high-impedance load for that particular setup, it was more cost effective to do it that way than to purchase many AC voltage sources.  I was kind of hoping that there was a similar solution for AC current. Perhaps a similar setup using lower voltage and a step-up transformer, assuming the amplifier has enough wattage for each channel.  This time however, we're looking at a low-impedance load where a 0-5A AC Current Transformer would normally be connected in the field.

I'd looked at those programmable sources that you cited, but with space and budget limitations, I'm not sure if we could do it.  If it's the only way then I'll have to convince the decision makers make some room and cough up some additional dough.

The type of simulation we're doing (for a test bed) requires that each line (phase) be able to be individually controlled to test behaviors from desired and undesired phases, frequencies and levels.  The Chroma source would do everything we need, but is really overkill for our needs.  I've also looked into an equivalent Elgar 3 phase sources as well.

Thanks for the ideas so far though, gives me things to look into!

Edited June 8, 2017 by Bryan