Medium Frequency Transformers for DC-DC Converters applied to Renewable Energies

Abstract

The medium frequency transformers (MFTs) are key components of DC-DC converters, in order to achieve high performance and high efficiency. Also, they are a fundamental part for the development and improvement of renewable energy sources, such as photovoltaic systems and wind farms, as well as solid state transformers and electric vehicles. A high power density, weight reduction and physical dimension are key characteristics in the design of these devices. The increase of the design frequency makes possible a high power density. The weight reduction of the device requires the use of new methodologies and different materials compared with those used in conventional 60 Hz transformers. This article presents an analysis of a MFT (1.75kVA at 5kHz), with a nanocrystalline core. The results of this work show that MFTs with this kind of core have favorable characteristics such as high efficiency and high power density for a medium frequency range in DC-DC converters.