In order to promote the low-carbon transition of coal-fired power units and cope with the large-scale wind curtailment and low reserves amid the uncertainty brought by a high proportion of wind power

the integrated energy system urgently needs more flexible resources to ensure the secure

stable

and flexible system operation. In this paper

the low-carbon and flexibility retrofit of coal-fired power units is carried out

and a low-carbon economic dispatch of integrated energy systems considering “coal-fired+” coupling power generation and flexible resource reserves is proposed to jointly optimize the energy

reserves

and balancing service for other energy systems

reduce system carbon emissions

and improve system flexibility. Firstly

with the “coal-fired+” coupling power generation and carbon capture technology

the coal-fired power unit is transformed into a biomass co-combustion carbon capture power plant

whose energy flow and low-carbon characteristics are analyzed. Secondly

considering the coupling relationship of different energy systems

the energy and reserve models of flexible resources are established to share system reserves. Thirdly

considering the wind power uncertainty

a two-stage stochastic optimization model with flexible resource reserves is constructed. The two stages are coupled through reserve capacity

reserve deployment

flexible resource output

and energy regulation. Then

the ladder-type carbon trading is introduced to reflect the clean mechanism of“coal-fired+” coupling power generation

and decarbonize coal substitution. Finally

to minimize total system cost

different scenarios areset up through example analysis to show that the proposed method improves system flexibility while reduce carbon emissions and total costby 10.29% and 11.32% respectively.