Optimal placement of PMU and SCADA measurements for security constrained state estimation

► Observability analysis is done with both PMU and SCADA measurements. ► The optimal placement of both PMU and SCADA is achieved with IP and GA respectively. ► Factorization is used for choosing the candidate measurements in contingency cases. ► The optimizing candidates are done with binary IP under multiple measurement loss. This paper presents a method for the use of Supervisory Control and Data Acquisition (SCADA) and synchronized measurements for complete observability of a power system. Under normal operation, both Node Phasor Measurement Unit (NPMU) and SCADA measurements are optimally placed using integer programming and Genetic Algorithm (GA) respectively. The minimum condition number of the Jacobian matrix is used as a criteria in conjunction with GA to obtain a completely determined condition. Next, a triangular factorization approach is used to search for the necessary candidates for single branch outage and single/multiple measurement loss. These candidate measurements are optimized by the binary integer programming method. Numerical results on the IEEE test systems are demonstrated. The results clearly show the robustness of the method to obtain reliable measurements under both normal and contingency conditions.