Abstract:  The variability and uncertainty brought about by intermittent renewable energy generation （IREG） impose higher requirements on the operational flexibility of the power system. The scarcity of flexibility may result in load shedding and/or curtailment of wind or solar power. Given this background， the concept of flexible ramping product （FRP） thus comes into being and has gradually attracted extensive attentions， since FRP provides an alternative for enhancing the accommodation capability for IREG. Firstly， the definition and characteristics of power system flexibility and the procurement of flexible resources are clarified. Then， a real-time dispatch model considering FRP provided by generation units and demand response resources is presented. In the developed real-time dispatch model， multiple types of demand response resources are taken into account， and some operating constraints are respected including the ones associated with unit start-up/shut-down in future periods and ramping up/down rates. Next， scenarios with various corresponding actual load demands and power outputs from IRES are generated by the Latin Hypercube Sampling method based on forecasted values of load demands and power outputs from IREG， and the dispatch schemes are evaluated by simulating the actual dispatch process. Finally， the role of FRP in enhancing system flexibility and in enhancing the accommodation capability for IREG and the impacts of different factors on the system operational flexibility are investigated through case studies.

Key words: power system, intermittent renewable energy generation（IREG）, operational flexibility, flexible ramping product（FRP）, real-time dispatch, demand response（DR）