Abstract: In recent years, with significant changes in the load structure of the power grid and the rapid growth of new energy installed capacity, thermal power generation units are under tremendous peak shaving pressure. Analyze and adjust the reasons for the disturbance caused by the strong primary frequency regulation action on the water level of the high pressure heater in Unit 3 of our factory, resulting in the high water level protection action and high pressure heater disconnection of Unit 3, and develop an optimization plan. By summarizing the impact of excessive frequency regulation action on the stable operation of the unit during operation and under deep peak shaving conditions, we can accumulate certain experience for analyzing similar problems.