Abstract：Making full use of the regulation of flexible resources can effectively suppress the fluctuation of

renewable energy generation and ensure the economic and safe operation of power system. An optimal dispatching

method for power system considering the flexibility of battery energy storage systems（BESS）and pumped hydro

energy storage（PHES）was proposed. Based on the establishment of the flexible ramp-up（FRU）and flexible rampdown（FRD）requirement model，a mixed-integer linear problem（MILP）based temporal day-ahead securityconstrained unit commitment and re-dispatch with the objective of minimizing the cost of energy，reserve，and flexible ramp products（FRP）was formulated for the studies，which was solved using CPLEX solver. The IEEERTS-24 node system was taken as an example and the proposed model was studied on 4 cases to verify that the

proposed method can effectively improve the operational flexibility of power system and reduce operating cost.

      Key words：battery energy storage systems（BESS）；pumped hydro energy storage（PHES）；flexible ramp

products（FRP）；mixed-integer linear problem（MILP）；optimal dispatch