Parasitics of Orthocyclic Windings in Inductors and Transformers

Abstract

Orthocyclic winding in magnetic components is common in both laboratory prototyping and mass production, especially for round wires with curved edges. However, its impact on winding parasitics, i.e., winding capacitance, ac resistance, and leakage inductance, has not been systematically investigated yet. Omission or inaccurate calculation of these parameters leads to current ringing, additional losses, and even abnormal operations. In this article, three modified formulas for parasitics of orthocyclic windings are proposed, and the impacts of orthocyclic windings are comprehensively studied. Magnetic field distortion and air-gap effect are analyzed and compensated. The formulas are verified by finite-element method (FEM) simulation and experimental results. Finally, normal and orthocyclic windings are compared, and conclusions are listed to illustrate the impact of orthocyclic windings on parasitics.