Multi-rate State-Variable-Interfaced Decoupling Simulation Strategy for Large-Scale Power Electronics Systems

Power electronics systems are adopted to enable a more sustainable and flexible power grid. However, accurate and efficient simulation of large-scale power converters is challenging due to the large number of state variables and switching events. In this article, we propose a multi-rate state-variable-interfaced decoupling (MSVID) method to address this issue. The MSVID method partitions the entire system into smaller subsystems and enables each subsystem to adjust its step size adaptively and independently. Additionally, we introduce a derivatives correction mechanism to further reduce the computational points arising from the large number of switching events. A 2 MW four-port solid-state transformer with 554 switches is studied to verify the accuracy and efficiency of the proposed method. Under the same accuracy requirement, the average of computational points of the MSVID method is only one-fifth of that of the original SVID method and several-fold acceleration is achieved.