In contrast to the conventional synchronous generator

the renewable energy generation equipment emerges multi-timescale transient response characteristics during grid faults

which profoundly impacts the transient behavior and stability of renewable energy power systems. This paper firstly proposes the multi-timescale transient stabilization framework and summarizes the current research of transient instability mechanism. The sequential response and switching process of renewable energy grid-connected system is analyzed during various grid faults. The main architectures of transient stabilization mechanism research are summarized. Subsequently

an overview of the existing studies is carried out from three levels of transient stabilization mechanisms

i.e.

AC current timescale

DC voltage timescale and rotor speed timescale

and the main leading stabilization mechanisms in each timescale are condensed. Finally

to cope with the deficiencies of the existing studies

this paper prospects future research directions in terms of cross-timescale interaction mechanism

multi-scale nonlinear switching dynamics modeling

quantitative analysis of cross-timescales coupling system

and control theory under complicated perturbations.