Calculation of Inductance of Sparsely Wound Toroidal Coils

A. Pokryvailo [1],
[1] Spellman High Voltage Electronics Corporation, Hauppauge, NY, USA
Published in 2016

Analytical methods used for inductance calculation of toroidal coils yield large errors in the case of coils sparsely wound on low permeability cores. Numerical field calculations can provide “exact” figures. We have outlined several simulation methods. Simplifications, assumptions, and analysis bifurcations are described. In the model building, the first alternative is modeling full coil or using symmetry and thus modeling only part of the space. Both approaches were explored in this paper. Then, the winding was represented as a set of discrete toroidal turns, and then modeled as a toroidal helix. Both infinitely thin and finite thickness wires were modeled.
The main takeout from these simulations are physical aspects, which, if not revealed, were quantified, providing thus better insight into coils design and characterization.