Unwanted Lateral Air Gaps: Impact on the Inductance Characteristics of Dual Part Cores in Variable Inductance Application

This paper presents a new approach for the indirect measurement of the unwanted air gap in dual‐part electromagnetic cores, using designed experiments and simulations. Different possible scenarios for the unwanted air gap in a dual‐part electromagnetic core are investigated. From the experimental and simulation results, a lookup table is derived that allows the unwanted air gap to be determined indirectly. Furthermore, this lookup table is used in a variable inductor of a resonant converter, as a typical application, to demonstrate the importance of accounting for the unwanted air gap in the control of such converters.