Análise de observabilidade e criticidade de medidas na estimação de estado de sistema de potência

Abstract

The proposed methodology in this study enables the analysis of observability and criticality in the 5-bus test system and the IEEE 14-bus test system using the available measurements in each system, with a redundancy level close to 1.5. The observability of the network is analyzed using two numerical methods: first, by calculating the rank of the Gain matrix, and then by performing the triangular factorization of the Gain matrix, considering only the active power measurements of the system. The criticality of measurements allowed the identification of critical measurements. Thus, by removing one or more measures classified as critical, two different configurations were obtained for the two systems: one observable and another non-observable configuration. Furthermore, this analysis highlights the importance of using redundant measurements in the database so that if a meter fails, there is another to compensate for it, prevening the network from being without information. Regarding the identification of these critical measurements and critical sets of measurements, the Jacobian matrix factorization method was used. Finally, the state estimation program was executed to verify the results obtained in the observability and criticality analysis phases applied to both systems for the two configurations. The results of the observability and criticality analyses were obtained using the MATLAB environment, and the state estimator used AMPL. The results showed that for the observable configurations of the systems, it was possible to estimate the state variables of all buses in the system. For the non-observable configurations, the program did not converge correctly due to insufficient measurements to estimate the state variables of some buses in the systems.