Portal Analysis Approach Used for the Efficient Electromagnetic Transient (EMT) Simulation of Power Electronic Systems

Efficient electromagnetic transient (EMT) simulation is crucial for addressing the challenges associated with the modularity, cascading, and complex topologies of power electronics (PE) systems. This article introduces a novel portal analysis (PA) approach that adopts a unique “port-component” view, leveraging the characteristics of “ports”. Different from the classic nodal analysis (NA) method, the networks and the components are described based on the portal voltage equations with lower orders. Furthermore, a port tearing method is introduced to partition the circuit, resulting in a block-bordered-diagonal (BBD) matrix and a small number of boundary variables in the extended port equation. The parallel processing of the network solution is implemented by utilizing the BBD forms and the band features. To validate the effectiveness of the proposed PA approach in capturing dynamics, a down-scale dual active bridge (DAB) prototype is constructed. Additionally, a simulated microgrid comprising cascaded H-bridge-type-DAB (CHB-DAB), solar photovoltaic (PV), and energy storage system (ESS) is used to furtherly verify the accuracy and efficiency. The results demonstrate that compared with the NA-based methods, the proposed models exhibit high precision under various transient conditions, with maximum relative errors of less than 2%. Moreover, they achieve a remarkable acceleration of one to two orders of magnitude.