Optimizing Electromagnetic Transient Simulation of Voltage Source Converters via Integrated Lagrangian Dynamics with Switching-State Prediction

High-fidelity electromagnetic transient (EMT) simulation with superior computational efficiency ensures the dynamic stability and grid-code-compliant operation of modern power systems dominated by voltage source converters (VSCs). However, traditional EMT simulation methods experience significant efficiency degradation when simulating large-scale systems with high switching frequencies. To address this challenge, this paper introduces an integrated modeling framework that combines Lagrangian mechanics with switching-state prediction. The Lagrangian model, developed within the configuration space of generalized coordinates, simplifies dynamic modeling and enables analytical system analysis. Additionally, the switching-state prediction algorithm eliminates the need for global iterative judgments. This unified approach not only facilitates the selection of numerical methods flexibly but also efficiently determines switching states. Moreover, the proposed framework can be easily integrated with other optimization techniques in EMT simulation to enhance computational performance. Validation through various case studies involving half-bridge sub-circuits and full VSC systems across PSCAD and MATLAB platforms demonstrates that computational efficiency is maintained.