A Novel Decoupled EMT Approach and Parallel Simulation Framework for Modularized Solid-State Transformers

Electromagnetic transient (EMT) modeling for the modularized solid-state transformer (MSST) faces critical difficulties because the dynamics of the complex-structured submodules, which contain dual active bridges (DAB) and multiple active bridges (MAB), are hard to be described in analytical formulas. Existing models have problems of a narrow dynamic frequency band, insufficient simulation accuracy, or are unable to operate under fast transients. This paper proposes a parallel simulation framework for MSST that preserves the original model's broadband characteristics and remarkably improves the simulation efficiency. The main novelty towards previous work is the detailed modeling of the multi-winding transformer, the decoupled modeling of the submodules, and the parallel design of simulation processes. Finally, the proposed framework is verified through the accuracy and efficiency analysis carried out in PSCAD/EMTDC. The simulation results verify that the proposed framework has excellent accuracy and time efficiency.