Influence of UPFC device on power system state estimation

The paper presents comparative studies of state estimation for a power system with and without the UPFC device. Weighted least squares state estimation is considered. Such parameters of state estimation are taken into account as: the condition number of the gain matrix, parameters characterizing accuracy of estimation results, and number of iterations in a computational process. During investigation, impact of existence UPFC in a power system on the mentioned parameters of the state estimation is analyzed for different coordinate systems, in which state vector is considered, for different levels of stress of a power system and data redundancy. In the paper, the considered parameters of state estimation are determined for the IEEE 14-bus test system. The results of the analyses show, that in general, impact of existence UPFC in a power system on features of the state estimation is negative, and particularly essential in some cases.