Design and characterization of high-frequency magnetic links used in power electronic converters

Nowadays, it is common to use high-frequency magnetic links in designing grid-connected power electronic converters, which can provide electrical isolation without increasing system volume and weight. The modular multilevel cascaded (MMC) converter topology has received significant attention in designing medium or high-voltage converters, but it requires balanced multiple isolated DC sources. To couple a renewable energy source to the MMC converter, a high-frequency magnetic link with multiple secondary windings can be an excellent option and is explored in this chapter. The high-frequency magnetic link is used to generate the isolated balanced multiple DC supplies for all of the H-bridge inverter cells of the MMC converter from a single, low-voltage power source. Compared with the conventional power frequency transformers operated at 50 or 60 Hz, the high-frequency magnetic links (in the range of a few kHz to MHz) have much smaller and lighter magnetic cores and windings, and thus much lower costs. The selection of core material and the design of magnetic link are multiphasic problems, which highly affects the efficiency of the magnetic link. This chapter presents the design and characterization of high-frequency magnetic links with advanced magnetic materials. © Springer-Verlag Berlin Heidelberg 2014.