An efficient OPF based approach for identification of infeasible contingencies and preventive rescheduling

Line and generator outages pose security threats for a power system. Co-ordinated preventive and corrective rescheduling actions attempt to make the system correctively secure with respect to these detrimental contingencies. This is an iterative process and is also computationally onerous. This paper attempts to reduce this burden in a twofold manner: firstly, by developing an OPF index based method for quick identification of infeasible post-contingencies and secondly, by reducing these indices for identified infeasible contingencies in a preventive rescheduling manner. Hence, a non-iterative Primal-Dual Interior Point Method (PDIPM) based OPF approach, requiring only one common pre-contingency Hessian factorization in all the critical contingencies, is proposed for fast identification of infeasible outages. The preventive OPF thus performed is also efficient as indices for identified infeasible contingencies are used as constraints and full OPF solutions for all critical post-contingencies are completely avoided. Results for two IEEE test systems and a fictitious 1000 bus system have been obtained to ascertain the potential of these methodologies.