A High Frequency Power Transformer for isolated bidirectional DC-DC Converter used for MVDC Collection System in Wind Farmser

摘要

In this article, a novel structure of High Frequency Power Transformer (HFPT) is proposed to be used in modular, isolated and bi-directional DC-DC converter in wind farm MVDC collection system. Tunable leakage inductance, high power density, MV level isolation between the windings, modular and scalable structure and effective thermal management are the features of the proposed HFPT structure. The laminar structure of the proposed HFPT makes it practical for cascaded architectures where multiple low voltage (LV) converters are connected to obtain medium voltage (MV) levels which is used in collection grids in wind farms. Capacitive coupling between the windings are minimized using the split winding configuration. Rectangular litz wire is considered for windings to obtain high efficiency at high switching frequency. Nanocrystalline based magnetic core is considered for core material and an Epoxy resin as an insulation layer between the winding and the core. An analytical thermal model is developed for the proposed architecture and analytical design results are provided.