A Low-Carbon Control Strategy for a Wind–Hydrogen–Ammonia Coupled Thermal Power System

As renewable energy integration increases, improving wind energy utilization and reducing carbon emissions from thermal power units have become key challenges for low-carbon power system operation. This study proposes a low-carbon control strategy for a wind–hydrogen–ammonia coupled thermal power system. First, a multi-energy-flow coupling model integrating wind-powered electrolytic hydrogen production, hydrogen storage, ammonia synthesis, and coal–ammonia co-firing is established. On this basis, a multi-objective interval-based energy management system (EMS) considering the temporal causality of hydrogen utilization is developed. The EMS explicitly distinguishes hydrogen stored at the end of the previous dispatch interval from hydrogen newly produced in the current interval. Hydrogen produced during the current dispatch interval cannot be directly used for ammonia synthesis within the same interval and is used only to update the end-of-interval hydrogen storage state. This treatment maintains temporal consistency among hydrogen production, storage, and utilization. Particle swarm optimization (PSO) is then employed to coordinate thermal power output and the ammonia co-firing ratio to reduce system operational CO2 emissions and grid electricity purchases while smoothing thermal power output. The proposed strategy is evaluated through nine typical-day simulations, parameter sensitivity analyses, algorithm comparisons, and a year-round continuous simulation. Under the typical-day scenarios, the maximum system CO2 emission reduction rate reaches 29.70%. PSO achieves system operational CO2 emissions comparable to or lower than those obtained with the genetic algorithm (GA) and performs better overall than the single-step baseline method. In the year-round continuous simulation, system operational CO2 emissions decrease from 998.968 kt for the pure-coal baseline under the same thermal power output trajectory to 961.255 kt, corresponding to an annual reduction rate of 3.78%. The annual average ammonia co-firing ratio is 7.21%. The results show that the proposed low-carbon control strategy can coordinate wind energy utilization, hydrogen–ammonia conversion, and low-carbon operation of thermal power units while satisfying multi-energy-flow operating constraints and the temporal causality of hydrogen utilization. This study provides a system-level control and dispatch approach for wind–hydrogen–ammonia coupled thermal power systems.