An Improved Approach for Design of Inductors with Air Gaps

Inductors play an essential role in the design of power electronic converters. Typically, the cores selected for high-current applications are built with air gaps. However, introducing an air gap results in fringing, making the design challenging. The extent of fringing depends on the air gap length and cannot be captured using a single equivalent circuit. This paper presents an improved approach for the design of inductors with air gaps. The proposed approach is based on a metric that signifies the accuracy in modeling the effect of fringing. In addition, the proposed approach also reports an optimization algorithm for the design of an inductor that accounts for different constraints. The inductance designed using this approach is compared with the existing methods and the models from the FEMM software. The proposed algorithm is validated experimentally using a small boost converter setup.