Pseudo load model-based power system identification for eigenvalue estimator

This paper discusses an eigenvalue estimation method suitable for wide-area and real-time stability monitoring of large power systems. Eigenvalues corresponding to electromechanical dynamics can be obtained from system matrix identified based on synchronized measurements of rotor angles and rotor speeds of generators and load fluctuations. One problem to actualize the eigenvalue estimation is high equipment cost of measuring enormous number of load fluctuations. In the paper, in order to solve the problem, we propose a new concept of pseudo load model which is assumed to express dynamical characteristics of loads. By introducing the load model, the composite dynamics of power systems and loads is identified from the synchronized measurements of only machines. Even if the load fluctuations do not have white noise characteristics, the eigenvalues can be obtained based on the composite dynamics identification. In the paper, the effectiveness of the pseudo load model in eigenvalue estimations is confirmed by simulation studies using 3-machine power system model.