A Decoupled Dynamical Simulation Method via Modal Partition

Dynamical simulation or numerical integration is an important tool used to study dynamical systems. For electric power systems, dynamical simulation is used for analyzing power system dynamics with respect to aspects such as stability and control. For stiff systems, implicit algorithms are typically used to obtain numerical stability, but these are inefficient compared with explicit methods. A hybrid scheme, the decoupled method, combines implicit and explicit formulas to realize both advantages. This paper proposes a decoupled dynamical simulation method based on modal partition and demonstrates its application to electric power systems. The decomposition is achieved in original state space, and stiff and non-stiff subsystems are treated by implicit and explicit methods correspondingly. A numerical stability analysis is given. The computational efficiency and numerical stability of the proposed method are demonstrated through a test power system.