Dynamic Phasor-Based Stochastic Transient Simulation Method for MTDC Distribution System

To investigate the impact of uncertain variability on multiterminal dc distribution systems and provide an efficient simulation tool, this article develops a stochastic transient simulation method based on dynamic phasor (DP). Starting from the lumped elements, the dynamic phasor models of the elements with parameter migration are established first, as well as the corresponding dynamic companion circuits used in digital simulation. By introducing the switching function and low-frequency approximation, the DP-based companion circuit of the voltage source converter is formulated, and the revised nodal voltage equations that can be solved in the framework of Electromagnetic Transients Program are also derived. Then, combined with the discussion on the ill condition of the nodal admittance matrix, the main process of DP-based stochastic transient simulation and the hybrid simulation scheme integrating electromagnetic transient (EMT) simulation are further proposed. Through the comparison with the full EMT simulation and physical experiments, the effectiveness of the DP-based dynamic companion circuits is validated, as well as the efficiency of the proposed simulation method.