A Novel Approach for Dynamic State Estimation with Synchrophasor Measurements

Abstract:
Synchrophasor measurements have been widely used in power system dynamic monitoring and control, such as low frequency oscillation identification and damping control, stability assessment and preventive control, etc. However, as a measurement tool, phasor measurement unit (PMU) unavoidably experiences the measurement error and bad data, especially in the dynamic process. If the raw measurements are applied in power system analysis and control directly, the unexpected consequence may be resulted in. Aiming at this problem, a novel dynamic state estimation method considering speed governors in electromechanical transient process is presented in this paper. The detailed mathematical model of speed governors and the schematic diagram of the presented method are given. The unscented Kalman filter (UKF) is suggested to solve the proposed estimation problems due to its advantage for solving nonlinear filtering problem. The simulations show that the accuracy of the proposed method is higher than the method that the mechanical torque is assumed to be constant.