To enhance the operational flexibility of coal-fired power plants in supporting high penetration of renewable energy, this paper focuses on the coordinated planning of regional coal-fired power flexibility upgrades. Existing research typically optimizes deep peak-shaving modifications on the boiler side of condensing units and thermal-electric decoupling technologies separately, with most studies neglecting the impact of grid structural constraints. this paper first systematically analyses the operational characteristics of four technical approaches: deep peak shaving modifications on the boiler side, zero-output modifications for low-pressure cylinders, electric boilers, and thermal storage devices. Subsequently, a mixed-integer linear programming model incorporating grid topology is constructed. This model aims to minimize total system costs, enabling the coordinated configuration and operational optimization of multiple technical pathways. A case study based on an enhanced IEEE 14-node system demonstrates that integrated optimization of these technologies reduces total system costs by 5.98% and curtailment rates for wind and solar power by 15.68%. The results validate that the proposed collaborative planning approach effectively integrates complementary advantages across different technologies, significantly lowering system costs and alleviating pressure on renewable energy integration. It also reveals that the flexibility regulation capacity of coal-fired power plants is influenced by their node position within the grid.

China seeks to reach peak emissions in 2030 and to be carbon neutral in 2060. All industries and regions in China need to develop low-carbon energy system development plans according to their own resources and development expectations to reduce the costs of carbon emission reductions. This paper presents an energy system development planning model based on the superstructure modeling method for planning how to control the emission peak goal. This model starts with the regional energy system structure and infrastructure. The model then considers various energy supply, transformation, transmission, and storage methods and possible changes in consumption technologies during different periods to obtain the best low-carbon development path with the optimal total energy system cost. This study then determines the best energy system development path from 2021 to 2035 for a typical city which controlled the peak carbon emissions to 179 million tons and reduced carbon emissions by 150 million tons within 15 years.