Optimizing HVDC Grid Expansion and Control for Enhancing DC Stability

Abstract

This paper analyzes the problem of the expansion of an offshore HVDC network. We assess which new HVDC link deployment ensures the highest stabilization of the DC voltage under transient conditions, in the worst-case scenario and for a given grid topology. A linear feedback controller is also designed to guarantee the minimization of the DC grid voltage deviations, while ensuring input constraints. The operation of this controller is compared to that of a standard droop regulator commonly applied in multiterminal Voltage Source Converter (VSC)-based HVDC networks.