A 3D Folded Power Inductor with PCB based technology for applications in the kW range

This paper presents an original 3D folded power inductor concept using Printed-Circuit-Board (PCB) technology. It is low cost for mass production and presents good reproducibility. A partial milling of the PCB is used to allow bending and building the inductor winding. A prototype is designed through an optimisation procedure. The frequency dependency of the series resistance, which widely impacts the losses in power converters, is investigated. Electrical and thermal tests are realised on the inductor to validate the applicability in power converters, e.g buck/boost inductor or EMI filter inductor, in particular differential mode inductor. These tests shows that the proposed inductor is a good candidate for power converters in the kW range.