A Comprehensive Review of Advanced Core Materials-Based High-Frequency Magnetic Links Used in Emerging Power Converter Applications

Clean and sustainable renewable energy sources (RESs) are increasingly becoming the better replacement for traditional fossil fuel-based electricity generation. RESs are typically connected with the utility grid through power electronic energy conversion systems. Power electronic energy conversion systems are becoming increasingly important for distribution networks, electric vehicles, or renewable energy applications. Magnetic links (MLs) play an important role as an isolating medium between the input-output stages of the converters in power electronic energy conversion systems. ML can also be used to increase fault-tolerant capability and enhance the power transfer reliability of the system. By increasing the frequency, the size of the ML can be reduced. However, some challenging technical issues with the ML operating with medium/high-frequency (HF) might affect the power converter performance. Several reviews have been published on the specific ML core materials for low-frequency applications. However, as the frequency used in the ML increases, there is an urgent need to investigate newer magnetic materials for use in such HFMLs, because, at medium/HF, the efficiency of MLs largely depends on the core losses that occurred due to the core materials. In this article, a comprehensive review has been carried out on the ML core materials for medium/HF applications from the historical development to the current status. The industrial production process of these materials from the raw phase to the production phase is presented. Electromagnetic and physical properties of the core materials are studied and addressed in the paper. Based on the properties, system requirements, and applications, a ranking has been proposed that can play an important role in selecting core materials for designing medium/HFMLs for power electronic energy conversion systems. A comparative analysis has also been carried out based on mathematical modeling and experimental core loss measurement techniques which can be used to predict the specific losses of the material. Finally, challenges to the design and implementation of medium/HFMLs for power converters are studied, and possible suggestions have been proposed to overcome the challenges to make the systems more efficient and reliable.