Influence of DC Voltage Droop Settings on AC System Stability

This paper presents a methodology to study the impact of different DC voltage droop settings on the AC system stability. When several Voltage Source Converters (VSC) in a DC system jointly control the DC voltage by means of droop control, an outage of one converter results in an abrupt change of the active power set-points of several other converters. This relative power change is related to the relative droop settings of the other converters. In this paper, the influence of the power sharing on the AC system stability is discussed by means of a singular value decomposition.