Decentralized Dynamic State Estimation with Missing and Delayed PMU Measurements

This paper studies decentralized Dynamic State Estimation (DSE) with missing and delayed PMU measurements in power systems. As data loss or delay can negatively affect the system state estimation and control, it is of paramount importance to account for the impact of data loss and delay. To this end, we propose a decentralized DSE scheme by utilizing a discrete Unscented Kalman Filtering (UKF). The proposed approach modifies the existing UKF by modeling the arrival rate of missing and delayed measurements as a stochastic process. We observe that there exists a critical value (threshold) for the measurement delay that depends on the measurement processing time of the state estimator, and measurements received beyond this threshold cannot be utilized for the DSE due to limited computation power. Numerical simulations under fault conditions in the simulated microgird show that the proposed scheme is able to avoid triggering unnecessary controlling and protection commands in the presence of contingencies.