Study of Bursting Oscillations in VSG System with External Excitation

When the virtual synchronous generator (VSG) is subjected to an external excitation and the frequency of the external excitation is much smaller than the intrinsic frequency of the VSG system, the VSG system will experience bursting oscillations, leading to system instability. In order to avoid the problem of VSG oscillating and then destabilizing under external excitation, this paper investigates the bursting oscillations and bifurcation mechanisms of VSG systems with external excitation. This demonstrates the VSG’s dynamic behavior and provides a theoretical basis for avoiding bursting oscillations, which is of great importance for the stable operation of the VSG system. Firstly, the mathematical model of VSG subjected to external excitation is developed by considering the external excitation as a slow-varying parameter. Secondly, the possible bifurcation of the system and the associated phenomenon of bursting oscillations are theoretically analyzed. Finally, the bursting oscillation process under different simulation conditions is revealed by nonlinear dynamics simulation. Hardware-in-the-loop experiment verifies the accuracy of the simulation results.