The microgrid with high proportion of new energy penetration has such characteristics as low inertia and weak dynamic frequency response ability of system. The frequency of the microgrid in island operation mode is more vulnerable to fluctuation. As for the frequency stability issue of the microgrid

the dynamic frequency response model is added to the optimal dispatch

and the system frequency security constraints are derived to improve the system frequency modulation capability. The dispatch model with dynamic frequency response constraints has such characteristics as multi-constraint

nonlinearity and high dimensionality. In the existing research the influence of linearization of the dispatch model is ignored. Based on this

the intra-day high-resolution discrete strategy is introduced into the day-ahead and intra-day two-stage optimal dispatch model of island microgrid considering dynamic frequency response. On the basis of day-ahead optimal dispatch

the high-resolution which can better fit the net load output curve of the system is selected for intra-day optimal dispatch and the day-ahead dispatch plan is corrected. Finally

the calculation simulation is performed and the simulation results show that the method can effectively improve the frequency modulation capability of the island microgrid and reasonably arrange the dispatch plan.