How physically large does a toroidal core need to be to handle a 100A smps buck or flyback configuration?
I used
Volts In 250 V Volts Out 25 V Load Current 100 A Freq. 50000 KHz Vripple 0.25 V Duty Cycle 10 % Ipp Inductor 5 A Ipk Inductor 102.5 A Irms 97.510683175401 A L 0.09 uH C 0.8 uF
which seems awful small? For a toroid, L = u*(rN)^2/D, and I played around with different sizes and giving me relatively large inductance's(much larger than 0.1uH).
steel core, r = 1cm, D = 5cm, N = 20, L = 700uH.
It seems that the inductance is pretty low for large currents,
Load Current 1 A Vripple 0.25 V Duty Cycle 10 % Ipp Inductor 0.001 A Ipk Inductor 1.0005 A Irms 0.99950004168751 A L 450 uH C 0.008 uF
So it should be relatively easy to get an inductor for doing 100A's for a buck converter? Even an air core would work?
If the calculations above are correct what are the real issued involved for high current inductors used in smps? Core saturation[how to calculate?]? Heat dissipation[Need thick wires => physically large inductor]? High frequency issues?
Can one buy off the shelf inductors that can handle 100A+ or would they be difficult to obtain the core material?