Research on Multi-Rate Simulation Interface Method for Hybrid AC/DC Systems

With the increasing integration of power electronic devices into hybrid AC/DC systems, the computational burden of electromagnetic transient simulation has significantly grown. Traditional single-rate simulation methods struggle to balance accuracy and efficiency in such complex systems. To address this issue, this paper proposes a multi-rate interface algorithm that enables effective boundary coupling between fast and slow subsystems. On the current transmission path, a sliding weighted average down-sampling method is designed to balance high-frequency noise suppression with dynamic responsiveness. On the voltage transmission path, a linear prediction-based interpolation algorithm is combined with a residual correction mechanism to enhance prediction accuracy and numerical stability under nonlinear disturbances. The proposed method requires no system identification or iterative solving, offering a simple structure and high implementation efficiency. Full EMT simulations on a hybrid AC/DC system verify that the proposed algorithm closely matches single-rate results during both steady-state and transient periods, demonstrating its practical applicability and potential for engineering deployment in large-scale power systems.