A Novel Multi-Rate Simulation Method of Power System Based on State-Space Branch Cutting and Variable Slope Interpolation Interface Algorithm

The continuous evolution of power systems and increasing integration of power electronic devices cause a progressive expansion of the system scale, which generates timeout issues in real-time simulation applications. Multi-rate parallel simulation stands as one of the key technologies for enhancing the simulation speed of complex power systems in real-time applications. However, this approach is often constrained by limited simulation accuracy. To improve the precision of multi-rate simulation, this paper proposes a novel multi-rate real-time simulation method that integrates the state-space branch-cutting method with a variable slope interpolation interface algorithm. In the proposed method, the system is divided into multiple subsystems through the cutting branch with each subsystem modeled by the state-space method. The time-step of each subsystem is determined by its inherent dynamic characteristic, and a variable slope interpolation interface algorithm is presented to facilitate data exchange between subsystems operating at different rates. Finally, real-time simulation cases demonstrate that the proposed method achieves an improvement in simulation accuracy exceeding 14.27% over conventional approaches.