https://en.wikipedia.org/wiki/Solid-state_transformer

Is AC electronic power converter, which can be reach 99% efficiency, and about 5% weight from conventional transformer, but that's still experimental now, think about electronic power converter that can convert 4kV to 110v replace conventional transformer that use winding, but I think it's reliability still questioned, and also maintenance maybe isn't easy

 

Ok, power distribution has nothing to do with an 1:1 isolation transformer.

Yes...

 

Like I said previously, nothing to do with an 1:1 isolation transformer.

Yes...

 

@anniel747 , Why 1:1 transformer need more turn in secondary ?, It's not just make that transformer 1:1.01 than 1:1 ?

 

Why is not exactly in same turns ?

 

Why is not exactly in same turns ?

Because of the voltage drop across the winding resistances and inductances.
An isolation transformer is usually quoted at 230V output for 230V input at the rated load.
That means with no load the output will be greater than 230V by an amount known as the "regulation".

 

What's minimum turns for 220v 50hz isolation transformer ?
Is only 12 turns in primary and secondary enough ?, wire is 4.0mm diameter

Start here:

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3

Beyond that, look for Transformers 1 : Beginner's Guide to Electronics, from Elliot Sound Products- they used to have a website but the URL I have is gone. I know they exist elsewhere but don't have the URI.

 

Start here:

Title: Understanding Basic Electronics, 1st Ed.
Publisher: The American Radio Relay League
ISBN: 0-87259-398-3

Beyond that, look for Transformers 1 : Beginner's Guide to Electronics, from Elliot Sound Products- they used to have a website but the URL I have is gone. I know they exist elsewhere but don't have the URI.

https://sound-au.com/

 

https://sound-au.com/xfmr.htm
https://sound-au.com/xfmr2.htm
https://sound-au.com/articles/xfmr3.htm
https://sound-au.com/articles/xfmr4.htm

Nice answer... thanks...

 

You're welcome.

Ok..

 

I have used a 1:1 turns ratio transformer for an AUDIO application to isolate a microphone balanced line from an amplifier. I have also used an isolation transformer from a balanced phone line to avoid mains frequency hum. In those instances the amount of power was very small, generated by a dynamic microphone. So the output voltage was very close to the input and the loss was not much.
A multi-KVA transformer is entirely different. If it is intended to deliver the output at the same voltage as the input it must compensate for all of the losses.
So the problem is in the terminology: is it a 1:1 turns ratio transformer, or is it a 1:1 voltage ratio at rated load? Quite a large difference.
And I realize that others have possibly provided the similar answer. Oh Well.

 

I have used a 1:1 turns ratio transformer for an AUDIO application to isolate a microphone balanced line from an amplifier. I have also used an isolation transformer from a balanced phone line to avoid mains frequency hum. In those instances the amount of power was very small, generated by a dynamic microphone. So the output voltage was very close to the input and the loss was not much.
A multi-KVA transformer is entirely different. If it is intended to deliver the output at the same voltage as the input it must compensate for all of the losses.
So the problem is in the terminology: is it a 1:1 turns ratio transformer, or is it a 1:1 voltage ratio at rated load? Quite a large difference.
And I realize that others have possibly provided the similar answer. Oh Well.

Ok...

 

The paper linked in #42 gives formula for turns in a 50 Hz transformer with a steel laminated core. It is:

T = 45V / A

Where T is turns, V is volts and A is cross section area of core in square cm.

So lets see what area you need for a 230V primary of 12 turns.

12 = 45 x 230 / A

A = 45 x 230 / 12 = 862.5

So, you can have a 12 turn primary! All you need is a core with 862.6 square cm cross section.

Bob

 

But the flux density, Bob!
You need to know the magnetic flux density the iron core you plan to use saturates at. That affects the number of turns.
Also the current density in the wire. A 25kVA transformer is not a project to be taken lightly. I take it you have access to core laminations which will fit into a circular bobbin - that is how large transformers are often built, but the laminations have different sizes depending on whether they are at the outside or the centre.
The poster mentioned the basic TPV formula TPV=1/(4.4.fAB) A=core cross section, B=flux density (max), f=frequency) but the power capability sets the area. All standard metric units square meters, Teslas and Hz- saves messing about with conversion factors. Typical iron cores work at flux densities from 1 to 1.5 T but if use grain oriented silicon steel 1.7 is possible, as long as the magnetic field is always in the grain oriented direction (works with C and toroid cores).
I suggest a delve into transformer design is needed - I don't know about ESP's link.

 

Yes... but why ? 1:1 need's more turns in secondary ?

When the primary is driven current is used from the primary to magnetize the core. Depending upon the particular design, this magnetizing current can be a large fraction of the input current, though it is shifted 90° (in time) with respect to the load current because it flows in an inductor. That current causes an unavoidable voltage drop within the primary. This results in distortion and a reduction of the waveform in the secondary. More turns are needed on the secondary to compensate for this loss.

This phenomenon is also at least part of the reason why driving transformers "backwards" gives disappointing results.