A study on power system state estimation under extremely bad conditions

During the operation of modern power system, the unanticipated occurrence of large disturbances, communication errors, exceptions in SCADA system and lacking of maintenances etc will affect the normal operation of state estimation, which plays a significant role in keeping the security of power system. Therefore, to seek a state estimation algorithm that can keep fairly good momentum and can obtain a relative accurate result under these extreme conditions is meaningful both in theory and in practice. On the basis of analyzing the extremely bad conditions and the unfavorable impactions they brought during the system operations, this paper proposes a state estimation method which consists of heuristic double topology modeling method and WLS state estimation on the combination system. In the method, the accuracy of the structure model and the measurements, which are the determining factor of the state estimation result, can be ensured by the heuristic double modeling method, therefore, the state estimation in this paper can still obtain a relative accurate result even in extremely bad conditions. The testing scenario proves the validity and availability of the method in this paper.