A Compound 10kV DVR System based on Solid State Transformer Structure

A new simplified dynamic voltage restorer (DVR) topology is proposed to compensate for voltage abnormality in this paper. Inspired by the general three-stage solid state transformer (SST) structure, the proposed DVR structure can not only realize voltage compensation for medium voltage grid, but also possess a smaller volume compared to the conventional DVR system by replacing all the line frequency transformers with high frequency transformers. Compensation criteria and control strategies on system level and stage level are given and analyzed. Finally, simulations are carried out and verify the feasibility and validity of the proposed topology and control method.