Dynamic equivalent state estimation for multi-area power systems with synchronized phasor measurement units

This paper proposes a new approach for state estimation of angles and frequencies of equivalent areas in large power systems with synchronized phasor measurement units. Defining coherent generators and their correspondent areas, generators are aggregated and system reduction is performed in each area of inter-connected power systems. The structure of the reduced system is obtained based on the characteristics of the reduced linear model and measurement data to form the nonlinear model of the reduced system. Then a Kalman estimator is designed for the reduced system to provide an equivalent dynamic system state estimation using the synchronized phasor measurement data. The method is simulated on two test systems to evaluate the feasibility of the proposed method.

► A new approach is proposed for state estimation of angles and frequencies of equivalent areas in large power systems.
► The Kalman estimator is designed using the synchronized phasor measurement data.
► The results of the Kalman estimator only reflect the inter-area oscillations of the systems.
► The proposed method shows good performance in spite of the loss of PMU inputs.