Analysis of Transient Voltage Distribution in Conventional and Flyback Power Inductor Windings

Abstract:
The steep voltage slopes of SiC and GaN semiconductors pose challenges for the insulation of magnetic components. Nonlinear potential distributions can occur, significantly increasing insulation stress. This study investigates these effects on a power inductor for a buck converter. The transient behavior of a conventional winding is compared to that of a flyback winding. For this purpose, a multi-conductor model is used, representing each turn of the winding as an RLC network. The turns are fully coupled both electrically and magnetically. The calculated transient voltage distributions at different rise times are compared with measurements. This analysis is used to evaluate voltage differences between adjacent turns along the winding and opposing turns in the layers.