Influence of Boiler Model on Simulation of Primary Frequency Regulation of Thermal Power Units

With the increasing proportion of new energy integration into the grid, frequency safety issues in the power system have become prominent. The importance of unit frequency regulation capability and grid frequency dynamic analysis has become increasingly prominent. At present, the primary frequency regulation model commonly used in power simulation for thermal power units does not include the boiler module, and its simulation results differ significantly from the actual situation in large frequency difference accidents. Although adding a boiler model can improve simulation accuracy, it is still necessary to clarify how the boiler and boiler control model affect the primary frequency regulation of the unit. This paper combines medium-to long-term simulation of power systems and thermodynamic principles to provide a detailed model of primary frequency regulation with boiler dynamics. On the basis of detailed models, three models are simplified. And the effectiveness of all models is verified. By comparing the simulation frequency differences of different models in a single machine load system, this paper concludes that the dynamic control of the boiler has a small impact on primary frequency regulation, but the influence of boiler physical dynamics increases with the increase of frequency regulation power. The conclusion of this paper clearly answers the necessity of boiler models in primary frequency regulation, which is helpful for the selection of thermal power unit models in advance frequency warning.