Optimal Power Flow modeling of hybrid AC/DC systems

The theoretical and practical implementation of optimal power flow (OPF) for high-voltage direct current (HVDC) grids, both the standard and security constrained OPF are presented as an extension to the deterministic alternating current (AC) optimal power flow case. This chapter first introduces the AC OPF case, and discusses the global convergence of optimization cases. It then reviews the extension of the AC OPF for hybrid AC/DC systems. This is done for a normal OPF and for the security constrained OPF. Two different approaches, namely preventive security measures and curative security measures are possible to manage contingencies for operators and grid planners depending on the nature of the contingency and the time available for corrective actions to pilot the grid back into a healthy state. Preventive security measures are taken in advance of a contingency which allow the system to remain secure after a possible outage.