Computationally Efficient Transient Stability Modeling of multi-terminal VSC-HVDC

Abstract

This paper studies the inclusion of averaged VSC-based grid interfaces and HVDC networks into stability type simulations, and compares the accuracy and speed of three multi-terminal DC dynamic models: 1) a state-space based model, 2) a multi-rate improved model, and 3) a reduced-order model. The accuracy comparison is conducted by qualitative time-domain analysis taking the state-space model as a reference whereas the computational aspects are investigated by the respective execution times. The models are demonstrated on a three VSC terminal, two synchronous area system. It is shown that the reduced-order model is too inaccurate to investigate detailed large-disturbance stability-related dynamics. The multi-rate model shows the best trade-off between simulation accuracy and speed.