State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing 102206, China

With the large-scale integration of renewable energy resources, the characteristics of decreasing and uneven distribution of the system inertia are becoming increasingly obvious. and the system frequency response is spatial and temporal distributed. An assessment method of system partition inertia based on differential calculation method is proposed. Firstly, the system is divided into several areas according to the similarity of frequency response characteristics and the dominant generator in each area is determined. Based on the partition and selection of dominate generators, a differential calculation method is proposed to assess the inertia level of each area using the interconnector power and the frequency of the dominant generators after disturbances. The proposed method requires only a few measurement data, which just needs to measure the data from regional interconnectors and dominate generators, and can be implemented by online estimation. The IEEE 10-machine 39-bus system is established in PSASP to verify the correctness of the proposed method in different operation conditions. The impact of the time period selection of disturbed data on inertia assessment is analyzed. The results show that the proposed method has high accuracy in inertia assessment of power system with the large-scale integration of renewable energy resources.