A novel Insulation Concept for an inductive medium Frequency Transformer for Solid State Transformer Applications

Inhalt:
The introduction of power electronics enables the enhanced usage and storage of renewable energy sources, especially in the medium voltage level. Thus, the focus advancingly shifts to DC-Applications. The connection of AC and DC dominated systems as well as the generation of high DC voltages can only happen by using power electronic systems in connection with Medium Frequency Transformers (MFT). Hence, galvanic isolation can be ensured at the same time as a sufficient energetic coupling. Due to increasing voltage levels on Solid State Transformer (SST-) Systems, the MFT’s have to bear higher field stress and thus, in combination of a dense insulation system and high switching-frequency losses (more warming) need to be redesigned. An alternative insulation system is introduced making use of a segmented magnetic core. Investigations on electric strength, partial discharges and the power factor were made and evaluated.