Benchmarking Linear and Non-Linear Behaviour of Power Inductors for Switched Mode Power Supplies

Abstract

Basic power electronic circuits (such as e.g. a Buck, Boost, Buck-Boost or half-bridge topology) for grid-connected applications are in general comprised of a voltage DC-link, two or more semiconductors and an LC input/output filter. The inductor is in general one of the more expensive and bulky parts and thus an optimized design is required in most network applications. Besides design parameters as volume, cost and frequency response, also a trade-off between low core losses, and maximum current excitation for critical operating conditions as e.g. overload capability exists. If the coil is not properly designed, the non-linear area of the inductor can be reached which results in faulty system operation of the device. Hence, a testbench conception is proposed in this paper, which allows to characterize both, linear and non-linear behaviour of power inductors for switched mode power supplies and/or network applications. Eventually, the prototypical setup and measurement results will be presented and compared to analytical results in order to verify the proper operation of the test system.