Design of Interleaved Boost Converter

[ssheikmd]

Dear All,

I have been reading interleaved boost converter related paper for couple of months now. I understand the concept of the converter. But, I couldn't find any useful formulas to design L&C values. Again, some claims the formulas are same as that of boost converter.. Here I need two things (a) Formulas to find L& C values. (b) If formulas are same as that of boost converter then in a two phase converter the inductor value should be as what we calculate or else should apply the parallel inductor equation..

Regards,

Sheik

 

[FlapJack]

There are many ap notes on designing boost converters. If you are going to interleave them you would design each section to be a fraction of the load depending on how many sections you will interleave.

If you design a 36vdc 10A boost converter and interleave 2 of them you will get 36vdc at 20A. If you use 3 of them you will get 36vdc at 30A.

The hard part of interleaving boost converters is the controller for them. I searched for them once and i think i only found a controller for interleaving 2 boost converters.

The reason it is so difficult for the controller is that each section must monitor current and all sections must cooperate and divide the current equally.

 

[BradtheRad]

Using Falstad's simulator, I have experimented with numerous interleaved converters.

Here is a screenshot of quadruple interleaved boost converters.



Notice I made the last coil higher than the others by 25%. I made the clocks evenly spaced.
The results of the simulation show current flow through the oddball is 16% less than the others (not 25% as we would expect).