A Graph Propagation-Based Automatic Differentiation Method for Power Electronic and Electric Machine Systems Simulation

This letter proposes an automatic differential method to enable the effective Taylor-series based flexible integration algorithm for power electronics and electric machine systems simulation. The proposed approach decomposes the system equations into linear and nonlinear parts and encapsulates the nonlinear part through controlled-source interfaces. Furthermore, this letter introduces a graph propagation-based automatic differentiation method (GP-AD), which enables the automatic generation of higher order derivatives for nonlinear portion. To evaluate the efficiency of the proposed approach, a case study on a power traction system of a high-speed train is presented. The results indicate that the proposed algorithm achieves a sixfold speedup compared to the commercial software, demonstrating the effectiveness of the proposed method.