1.School of Electrical Engineering, Southeast University, Nanjing 210096, China;2.State Grid Jiangsu Electric Power Co., Ltd., Nanjing 210024, China;3.China Electric Power Research Institute (Nanjing), Nanjing 210003, China

The increasing proportion of renewable energy has led to the reduction of the power system inertia level. To prevent rapid frequency drop after fault in the low-inertia system, it is urgent to explore new inertia response resources. Fast frequency response load (FFRL) can flexibly adjust the load level to provide emergency support according to the rate of change of frequency after the power grid fault. An assessment method for FFRL inertia support effect is proposed based on the system frequency response model of power system with FFRL participation. An optimization model for FFRL participation in inertia auxiliary services is established considering the inertia service compensation mechanism of different market entities. The calculation results have verified the accuracy of the proposed assessment method and the improvement effect of the participation of FFRL in inertia auxiliary services on system operation economy and system frequency safety and stability. Compared with traditional thermal power units, FFRL can provide more inertia response with less response capacity, and flexibly transform according to its response strategy and control method, thereby more accurately responding to the grid requirements for its own inertia level.

This work is supported by State Grid Corporation of China (No. 5108-202218280A-2-293-XG).