Stability assessment of VSC-HVDC connected large-scale offshore wind power: A North-Sea region case study

Large amounts of offshore wind power plants (WPP) connected through voltage sourced converter high-voltage DC (VSC-HVDC) technology can have significant consequences for the dynamic behavior of the related onshore AC systems. This paper explores the rotor angle stability effects of the integration of 35 GW of wind power in the North Sea, connected to the European mainland, Nordic, and UK power systems. It investigates the influence of the VSC-HVDC topology (e.g. radial versus meshed) and the DC power flow control strategy on the dynamic response of the connected power systems after common disturbances such as the outage of an offshore wind power plant and short-circuits in the AC grid. The results show a significant influence of the power flow control method applied. Radial VSC-HVDC connections for offshore WPPs can be designed such that the stability effects can be minimized, whereas meshed links may propagate disturbances from one synchronous area to another.