A three-stage SCOPF considering fast converter control and generator droop

The current developments in power system operation motivate a shift to a preventive-curative approach for reliability management. Large-scale integration of HVDC into the existing system is prompting the utilization of converters as an additional control for reliable AC/DC grid operation, especially for fast curative actions. To this end, this paper introduces a novel implementation of fast curative converter control and generator droop response after a contingency as a three-stage security constrained optimal power flow model for AC/DC grid. Significant advancement of this paper is in the extension of the existing two-stage approach to capture the additional flexibility of converter control in the short-term post-contingency stage and assessment of its impact on day-ahead operational planning decisions. Thus, a new mode of operation for the converters is suggested in the short-term period after an outage, wherein the active power set points can be adapted. The paper shows that the fast control of embedded HVDC converters is more beneficial during constrained grid situations. Including fast converter actions in reliability management results in cost savings of 0.4-9.8 million euros per year for the considered system.