Modeling of High Power Inductors Based on Solid Flat Wires for Compact DC-DC Converters

This paper presents modeling and formulations for power inductors based on solid flat wires for high power and compact DC-DC converters. Equivalent Series Resistance (ESR) of the inductor is formulated and modeled for DC and AC currents. Compared to a solid round wire inductor with equivalent wire gauge and similar window size, this paper shows that solid flat wires present better ESR for both AC and DC current components. The theoretical formulations have been verified by 2D Finite Element Method (FEM) simulations using ANSYS Maxwell. Eddy-current simulations show that the ESR can be formulated with excellent accuracy. Furthermore, the conduction losses of the flat wire inductors are generally formulated for DC-DC converters and verified by transient FEM simulations. To verify the theoretical formulations, a power inductor with maximum DC current of 80 A is implemented and tested for high power DC- DC converters.