Oscillation Center Migration Law in Multi-Frequency Out-of-Step Oscillation Scenario

Abstract

With the increase of the scale of AC / DC power grid and the operation mode, the applicability of out-of-step splitting devices based on the two machine model is seriously challenged. The migration law of out-of-step oscillation centers in multi-frequency out-of-step scenario is in urgent need of study. In this paper, based on the equivalent three machine system model, the multi frequency oscillation center voltage and position function are derived, voltage characteristics of multi-frequency oscillation center and the law of oscillation center migration when the system parameters change are analyzed, and research shows that migration scope and direction of oscillation center are jointly determined by the power potential amplitude ratio, the angular velocity and initial phase of power potential, while variation of angular velocity influences the migration speed of the oscillation center. The three machine system example is used to verify the influence of system parameters on the oscillation center migration in multi-frequency out-of-step scenario.