Research on State Estimation of Hybrid Power System Based on APSI Multi stage Strategies

By studying the requirement of high data accuracy and less calculation amount for state estimation in hybrid power system, two new estimation frameworks for SCADA/PMU hybrid measurement with multi stage strategy in power system state estimation is presented in this paper. A prior state information and a blocked version of orthogonal Givens rotations are applied to improve data processing capability of state estimation based on PMU/SCADA as to the first framework. A three level scheme depending on estimation fusion principle is proposed in the second framework, and the measured values of SCADA/PMU that are determined previously are optimized. The optimization degree of calculation amount and accuracy for multistage strategy is described, discussed and compared. The IEEE 30 bus test system is used to verify the validity of the multilevel strategy, by using of which the calculation amount of state estimation is effectively reduced and the synchronization and accuracy of measurement data are increased.