CNC-Manufactured Power Inductors with High Bandwidth for Multi-Megawatt Converters

Inductors are essential components of power converters - used as energy storage devices or filter elements. The progress of power semiconductors and converters (SiC, MMC) towards higher switching speeds and power levels enforces new inductor designs in order to meet the requirements for high bandwidth, low loss and power density. In this paper, a new planar inductor design with shielding plates is presented and evaluated, which enables excellent high-frequency behaviour and compact size. Moreover a simple CNC-based manufacturing process can be applied for industrial production. The new design is analyzed through FEM simulations and a medium power range demonstrator. Finally, the concept is applied to an arm inductor for a containerized 40-MVA Modular Multilevel Converter (MMC).