A Simple Pre-Estimation Method for Calculating the Inductance of a Variable Inductor

This paper presents a simple method for predicting inductance in applications of variable inductors with ferrite cores. Today, switching converters are widely used for voltage and current level conversion in renewable energy applications. The variation of inductance in switching converters improves the voltage gain range and other converter characteristics. In this paper, through the analysis of core saturation, a simple circuit model is proposed to predict inductance when the core reaches saturation. This model enables designers to predict inductance variations prior to the winding of the core and the construction of the inductor. Two approaches regarding core permeability are analyzed: the well-known Brauer relationship and a proposed alternative. Finally, the proposed method has been validated and tested on two types of cores, includes E42 and E55.