Looking for LT for three or more parallel aiding inductors

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Chris Fuccillo
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Formula for total inductance of two parallel coupled inductors: LT = (L1 L2 - M^2) / (L1 + L2 - 2M).


I need to calculate the mutual inductance between multiple aiding coils. The above formula is fine for 2 inductor but I'm looking to calculate the mutual inductance for up to 30 or more parallel coils wound on the same magnetic core. I can not find an example or formula for more than two coils, any help would be greatly appreciated.
 

Discussion

I believe the equation you give is for two nearby inductors, on different cores, but with some coupling.

If the parallel coils are wound on the same core, they will have M very close to 1.000
If all parallel coils have the same number of turns, the combination will reduce to just one inductor, but wound with thicker wire.

If the turns count is different then the series resistance of the coils will be important in limiting the circulating currents in the virtually shorted turns.