Study on Peaking Ability and Operation Safety of Thermal Power Unit in Peak Load Regulation of Power System

As the demand for renewable energy access to the grid grows gradually, the peaking function of thermal power unit in grid system is increasingly highlighted. This paper analyzed the security problems of thermal power unit load, and to carry out the load test at 8 units. We analyzed the safety index, including hearth negative pressure fluctuations, water-cooled wall temperature, axial displacement of turbine, and found that some existing units can achieve 60%-70% peaking capacity without flexibility transformation. The negative pressure of some units fluctuates greatly, which reflects the poor stability of the boiler in the low load stage.