Double-reheat technology stands out as an international leading coal-fired power generation technology for its high efficiency and cleanliness. However

the inclusion of an additional reheater elevates the thermal inertia of the thermal power unit

leading to greater complexity in process control. To enhance the flexibility and design a more intelligent control system

establishing a mathematical model that can concisely and accurately describe the dynamic characteristics is a paramount prerequisite. In this paper

based on the laws of mass and energy conservation

an analysis and modeling of a 1 000 MW ultra-supercritical double-reheat unit during wide load operation are conducted

and the model parameters are identified through the orthogonally designed fireworks algorithm. Close-loop simulation has demonstrated that within the dataset used in this study

the error outputs of the coordination system and the superheated steam temperature system is below 0.7%

and the reheated steam temperature error is below 1.3%. Open-loop simulation has indicated that the model can reflect the dynamic characteristics of the unit and can serve as a basis for the coordination and design of controllers for main steam and reheated steam temperature control systems.