A Novel High Efficiency High Power DC Hybrid auto-Transformer for DC Grid

This paper introduces a novel hybrid autotransformer topology for DC systems, tailored to connect different DC grids with high efficiency and power capacity. This design incorporates an energy storage arm based on a half-bridge submodule (SM) string for effective energy transfer, utilizing thyristors as switching devices, which can be easily connected in series. To optimize the active functionality of the energy storage arm, a control strategy is proposed that enables flexible current shaping in the arm and ensures reliable thyristor shutdown. The performance and effectiveness of the proposed topology and control strategy were validated using MATLAB/Simulink simulations.