Analysis of the Influence of Furnace Side Heat Storage Coefficient on Primary Frequency Modulation Capacity Under Deep Modulation Condition of Thermal Power Unit

Abstract

In order to study the influence of the heat storage coefficient of the furnace side evaporation section and superheating section on the primary frequency modulation capacity of the thermal power unit under the deep modulation working conditions, a refined simulation model suitable for the thermal power under the deep modulation working condition was built, based on the typical model in the transient stability program PSD-BPA, and the control logic of the thermal power unit under the actual furnace-machine coordination mode. The correctness of the model was verified by the actual primary frequency modulation data of a DC furnace with a rated power Pe of 1 000 MW at 35%Pe working conditions. Through the simulation model, the influence of the heat storage coefficient of the evaporation section and the superheat section of the furnace side on the primary frequency modulation capacity of the unit under the deep modulation condition was explored. It is found that the smaller the heat storage coefficient of the evaporation section on the furnace side, the stronger the primary frequency modulation response ability of the unit. The larger the heat storage coefficient of the superheated section on the furnace side, the more friendly it is to the primary frequency modulation of the unit. The frequency regulation capability of the unit can be improved by increasing or decreasing the heat storage coefficient in the evaporation and overheat sections. In addition, the refined model of primary frequency regulation established can provide analysis of the margin of primary frequency regulation for thermal power units for power production and regulatory authorities, which is beneficial for the safety of new power systems.

Keywords

• thermal power unit
• deep modulation
• thermal storage coefficient
• simulation model
• frequency modulation margin