Real-Time Power Loss Optimized Operation of a Solid State Transformer by Utilizing the Common-Mode Voltage

This article presents a general methodology and a real-time solvable, analytical model for reducing the total losses of the cells of a Solid-State Transformer (SST). The efficiency is increased with the usage of the online optimized common-mode voltage u CM . Measurements on a 400V AC to 750V DC , 45kW SST test bench verify the calculation results and the operating principle of the algorithm. A loss reduction of up to 20% is possible without introducing additional restrictions to the SST.