The expansion and development of power grid with voltage source converter based multi-terminal direct current(VSC-MTDC)system provides a new technical means for grid-connection of large-scale wind power and other clean energy. To have the DC power grid and AC power grid tightly coupled

the traditional scheduling application in the power grid dispatching operation business lacks consideration of direct control unit

AC/DC interaction

DC power flow constraints and other problems

which will face new challenges in the scheduling object

schedule model

equilibrium strategy and AC/DC bilateral network constraints

etc. Aiming at the problems mentioned above

the scheduling optimization modeling method with flexible multi-terminal DC grid is proposed. The proposed model can flexibly deal with AC/DC interaction. The added constraints are those on a new DC power grid active equilibrium and AC/DC bilateral network transmission limits

thus providing a reference for modeling strategy of DC power supply in the traditional scheduling application. The model proposed is applied to the 5-terminal DC power grid connected with the New England 10-machine system

which verifies the effectiveness of the model in the processing of the AC/DC interconnected power grid dispatching schedules.