Method for small signal stability analysis of VSC-MTDC grids

This paper deals with small signal stability analysis of Voltage Source Converter based Multitermial HVDC grids (VSC-MTDC). First, a simplified model is used to predict the voltage dynamic behavior. Next, a modular method to build the state space model of the overall MTDC system is described. Model validation is achieved in time domain by a comparison with an electromagnetic simulation in EMTP-rv. As concrete example of effective application, a parametric study on the droop value is carried on a 3-terminal meshed HVDC grid. This example attests to the effect of the droop parameter on the stability of the overall system.