transformer losses caluculation

[Romeo shashi]

Hello,

I want to use ferrite material core to design transormer in stepdown full bridge DC to DC coverter and the turns ratio I am getting
Np:Ns =>14:1 so can you sujest me a method to caluculate transformer core and copper losses which includes winding resistance and resistance of the core in the formula and i want to caluculate flux density(B) of the core by using number turns of the transformer


my specifications are:
i/p vol - 400v
o/p voltage - 28v
o/p power - 3kw
Frequency - 1mhz

 

[Anna Conda]

Hello is that 1milli-Hz or 1 MegaHertz..?

You would possibly be the first in the world to get a 3kW converter going with a switch frequency of 1000,000 Hz, 500nS per half cycle, 20nS transition times? at 400V = 20,000V per uS slew rate, it should be quite a radiator...! of RFI,

Will you be hard switching or resonant topology?

) good luck..!

 

[Romeo shashi]

Hi Anna thanks for the reply!!!

Here i need to find the losses in the transformer at different frequencies like 100khz(kilohertz) to 1mhz(megahertz).I am using fullbridge converter topology(input-400v and output-28v), can you please suggest me how to find transformer losses by using winding resistances of the core?
Please take a look at my circuit in this bellow link
https://obrazki.elektroda.pl/1179932100_1364662925.png
My specifications are:
i/p vol - 400v
o/p voltage - 28v
o/p power - 3kw
Frequency - 100khz to 1megahz
Np:Ns - 14:1

- - - Updated - - -

Hi Anna thanks for the reply!!!

Here i need to find the losses in the transformer at different frequencies like 100khz(kilohertz) to 1mhz(megahertz).I am using fullbridge converter topology(input-400v and output-28v), can you please suggest me how to find transformer losses by using winding resistances of the core?
Please take a look at my circuit in this bellow link
http://obrazki.elektroda.pl/1179932100_1364662925.png
My specifications are:
i/p vol - 400v
o/p voltage - 28v
o/p power - 3kw
Frequency - 100khz to 1megahz
Np:Ns - 14:1

 

[Orson Cart]

Core losses can be calculated using standard data and formulae provided by most core & ferrite manufacturers, wire loss is heavily dependent on the quality and size and stranding of the litz used and is generally harder to calculate accurately.

Why are you aiming for 3kW? Why are you aiming for 1MHz @ 3kW?

A 1 MHz transformer design (and construction) can be (usually will be) quite different physically from an 100kHz design.

 

[Romeo shashi]

Hello,
Thank you for replying
It is a high frequency DCtoDC converter so my specifications are like that i have to find the transformer losses at these power and at different frequencies. Currently I am caluculating with 500khz and 1megahz now i have calculated the copper losses using Ip^2Rp+Is^2Rs but how to find core losses using the core resistance can you give me some
formulaes or any paper to find the core losses which involves core resistance for ferrite material.