Solid-State Transformers Move Into Grid Demonstrations: MFTs Link Medium and Low Voltage

Why medium-frequency transformers are central to isolation, efficiency and reliability in grid SST demonstrations.

Solid-state transformers combine power-electronic conversion and high-frequency isolation to integrate voltage transformation, power-flow control, power-quality functions and DC interfaces. Recent U.S. Department of Energy projects include hybrid transformers, a solid-state PowerHub and storage-assisted transformer concepts, showing a transition from laboratory research toward distribution-grid demonstrations. The MFT sets size and insulation boundaries Core material, window utilization, leakage inductance, partial-discharge behavior and thermal structure collectively determine system efficiency and reliability. Higher frequency reduces volume but also raises core loss, AC winding loss and insulation stress. Design at system level Magnetic design inputs should include the soft-switching range, resonant parameters, overload curve, ambient temperature and fault transients rather than rated power alone. Source: U.S. Department of Energy transformer projects