Enabling HF power conversion : magnetic components and a wide voltage range converter

Abstract

High frequency switching in power converters offers the benefits of high power density and faster transient response; however, high frequency losses have limited efforts to increase frequency into the HF (3-30 MHz) regime. This thesis addresses two of the dominant frequency-dependent loss mechanisms: magnetic material core loss and switching loss. Appropriate metrics are derived to evaluate magnetic materials in core loss limited components. A survey of material core loss shows the potential for significant performance improvement in the HF regime using materials previously overlooked in the power electronics community. One such material is then used in a high frequency converter which achieves zero-voltage switching over a wide range of voltages and powers (e.g. for grid-connected applications). Using appropriate magnetic materials and converter techniques like those presented here, power densities in certain applications can be improved by an order of magnitude by operating at HF.