A new state updating approach in power system dynamic state estimation considering correlated measurements

摘要

Generally speaking, basic real-time measurements collected from different control centers have a time delay due to the transmission delay and data exchanges in the energy management system (EMS). Measurement errors resulting from both the raw measurement noise and time delay have undesirable effect on power system dynamic state estimation (DSE). In order to reduce measurement errors, accurate measurement modeling is considered to represent the characteristics of the actual telemetry system in the extended Kalman filter (EKF). Based on the improved model, a new state updating approach is proposed to deal with the issue of measurement delay. With the calculation of the covariance values, the estimation is updated by combining the time-delayed measurement data. Finally, some simulation results on IEEE 118-bus system are provided to verify the effectiveness of the proposed method, where a higher accuracy during large fluctuation, as well as a satisfactory performance during small change in the load can be obtained.