A Novel Medium Voltage Solid-State Transformer Using Advanced Magnetic Material-Based Three-Phase High-Frequency Magnetic Link

Abstract

The solid-state transformer (SST) is an emerging technology that offers promising benefits for electricity distribution and transmission systems, as well as its connection with sources of renewable energy (RE), battery storage, and electric vehicles. The high-frequency magnetic link (HFML)-based SST has enormous promise for solving problems associated with connecting the grid with RE and nonlinear loads and providing extra control functionality. Conventional modular SST topology with multiple active bridge (MAB) converters considers individual multi-winding HFML (MWHFML) in each phase. These systems have the drawbacks of power mismatch between the windings of MWHFML, system complexity for extended modular design, and system cost. This paper proposes a novel SST topology using a three-phase high-frequency magnetic link (TPHFML). Instead of using individual HFML in each phase of a three-phase system, only one TPHFML is used to simplify the entire SST topology. The proposed system reduces the power mismatch issues in the HFML, simplifies the system configuration, reduces 50% of components, and improves the overall efficiency. The proposed TPHFML-based SST system can offer approximately 11.45% higher efficiency than that of the existing MWHFML-based SST system. Experimental tests were carried out successfully to validate the scaled-down prototype of the proposed TPHFML-based SST topology.