The Bursting Oscillation Characteristics of DPMSG in Wind Farms and Its Interaction Effect Mechanism

ABSTRACT In wind farms with high penetration of renewable energy, the strong coupling and multi‐timescale characteristics between direct‐drive permanent magnet synchronous generators (DPMSGs) are prone to inducing complex nonlinear oscillations, which seriously threaten the safe and stable operation of the system. Aiming at the problem that existing studies are difficult to characterize the generation and propagation mechanism of oscillations under the action of multi‐timescale coupling, this paper takes the two‐machine coupled system composed of adjacent DPMSGs in a wind farm as the research object and systematically studies the bursting oscillation characteristics and interaction mechanisms of DPMSGs under disturbance conditions. Firstly, a mathematical model of the two‐DPMSG coupling system considering external slow periodic disturbances is established. Based on the fast–slow scale dynamics and transformed phase portrait method, the internal mechanism of bursting oscillations in a single‐machine system, which is jointly caused by subcritical Hopf bifurcation and multi‐attractor structures, is revealed. Secondly, combined with collective dynamics analysis, the propagation and evolution process of bursting oscillations in the two‐machine coupling system are deeply discussed, and various dynamic states such as oscillation suppression and synchronous bursting oscillations exhibited by the system under different coupling strengths, as well as their bifurcation mechanisms, are clarified. Finally, the influence of disturbance intensity on the stability domain of the coupling system is analyzed, and the law that the stable region for suppressing bursting oscillations through coupling regulation gradually shrinks with the increase of disturbance amplitude is revealed. The research results show that reasonable design of the coupling strength can effectively suppress the propagation of bursting oscillations, which provides a theoretical basis for the oscillation control and stable operation of the parallel DPMSG system in wind farms.