Robust Dynamic State Estimator of Integrated Energy Systems Based on Natural Gas Partial Differential Equations

The reliability and precision of dynamic database are vital for the optimal operating and global control of integrated energy systems. One of the effective ways to obtain the accurate states is state estimations.A novel robust dynamic state estimation methodology for integrated natural gas and electric power systems is proposed based on the Kalman filter. To take full advantage of measurement redundancies and predictions for enhancing the estimating accuracy, the dynamic state estimation model coupling gas and power systems by gas turbine units are established. The exponential smoothing technique and gas physical model are integrated into the Kalman filter. Additionally, the time-varying scalar matrix is proposed to conquer bad data in the Kalman filter algorithm. The proposed method is applied to integrated gas and power systems formed by GasLib-40 and IEEE 39-bus system with five gas turbine units. The simulating results show that the method can obtain the accurate dynamic states under three different measurement error conditions, and the filtering performance is better than separate estimation methods. Additionally, the proposed method is robust when the measurements experience bad data.