Robust and Security-Constrained Optimisation of Converter Droop Gains in Meshed HVDC Grids

In this paper we are presenting a preventive security constrained optimal power flow model for AC/DC grids using a robust optimisation of converter active power-voltage droop coefficients and generators and HVDC converters active and reactive power set points. The converters’ optimal droop control actions maintain system feasibility after DC grid contingencies. The model takes into account wind power and load demand uncertainties and uses a scenario based approach to robustly determine the HVDC converters’ voltage-power droop coefficients. The developed optimisation model is applied to a variety of AC/DC grid test cases for the analysis of its computational performance, convergence and AC feasibility of the obtained solution. Finally, we propose a number of future extensions and modelling improvements for real-life applicability of the developed model in the day-ahead operational time frame.