Analysis of calculation accuracy of power system electromechanical eigenvalues based on instantaneous power disturbance waveforms

The paper presents investigation results concerning the accuracy analysis of calculating electromechanical eigenvalues of the multimachine power system (PS) state matrix based on instantaneous power disturbance waveforms when taking into account introduction of a disturbance to different units. There were analysed the instantaneous power waveforms occurring after introducing the disturbance in the form of a rectangular impulse of different height to the voltage regulation system of generators in generating units of different powers. In order to increase the computation accuracy, computations were repeated many times. The computation results were averaged. The hybrid algorithm consisting of the genetic and gradient algorithms was used for computations