Carbon capture is a crucial technological pathway for carbon emission reduction in coal-fired power plants (CFPP). However

few studies have examined how integrated carbon capture systems affect the flexible operation of CFPPs. To address this gap

this paper develops a dynamic mechanistic model of a 1 000 MW ultra-supercritical coal-fired power plant integrated with a monoethanolamine-based post-combustion carbon capture (PCC) system. From an ancillary service perspective

the system's peak-shaving

primary frequency regulation

and automatic generation control (AGC) performance are comprehensively analyzed. Results show that

in terms of peak shaving

PCC flexible operation reduces the CFPP's adjustable load range by 8.86% but increases load regulation depth by 10.64%

achieving 15.81% higher deep peak-shaving revenue and 4.61% higher daily operational revenue. For primary frequency regulation

the PCC steam extraction valve provides additional capability

with frequency response indices of 0.427 9

0.785 7

and 0.870 3 within 0~15 s

0~30 s

and 0~45 s

respectively

meeting grid requirements. For AGC performance

the coordinated control system involving the PCC steam extraction and the boiler-turbine system achieves a comprehensive frequency regulation index of 3.01. Overall

the integration of a PCC system can significantly enhance the operational flexibility of CFPPs.