Efficient method for the real-time contingency analysis of meshed HVDC power grids fed by VSC stations

An efficient method for the real-time contingency analysis of meshed high-voltage direct current (HVDC) power grids fed by voltage source converter (VSC) stations is introduced here. A linearised AC/DC grid model is initially determined considering the control strategies of the various VSC units. This lays the foundations for the determination of linear sensitivity factors with which the contingency analysis is carried out to evaluate the real-time N-1 criterion in AC/DC grids, as demanded by system control centres. Distribution and power-injection factors are subsequently derived for efficiently assessing the impact of AC/DC transmission line outages and load/generator disconnections on the HVDC grid. Conversion factors are also derived to estimate the impact of the loss of VSC stations on the AC/DC network, this being another inherent contribution of this work. The efficiency and validity of this timely approach, which finds practical applicability to the real-time operation of HVDC power grids, is confirmed using a meshed DC network fed by three VSC stations. The disconnection of AC and DC transmission lines, generators, and VSC stations are dynamically simulated using Simulink and their post-disturbance steady-state conditions are compared against those computed by the introduced method where it is confirmed that both solutions concur very well with each other.