The Analysis and Calculation of Power Angle Transient Characteristics in VSG Control Using Parameter-Perturbation-Based Averaging Method

With the increasing penetration of power converters in modern power system, virtual synchronous generator (VSG) control is considered to be a promising method due to its grid friendliness. However, the lack of clear and accurate description of its power angle dynamics poses challenges to the stability analysis and converter parameters design. In this article, the Krylov–Bogoliubov averaging method, an effective parameter-perturbation-based analytical calculation method for dissipative process, is first presented to characterize the dynamic trajectory of VSG control. Moreover, the solvable problem is transformed from typical simple harmonic motion into damped oscillation, which redistributes the weights of solvable and perturbed problems. On top of that, an unperturbed-result-based averaging method is further proposed to obtain the explicit time-domain expression of power angle dynamics, which may provide good potential for transient stability analysis and grid-connected converter design. Finally, simulations and control-hardware-in-the-loop experiments have been both demonstrated to verify the effectiveness of proposed method.