Minimum Demand Inertia Assessment of Power System Considering the Load-side Resources

With the large-scale grid integration of new energy source, the power system synchronization inertia level continues to decrease. It is crucial to assess the minimum demand inertia(MDI) level required by the system to obtain the inertial security operation boundary. Most existing MDI Assessment methods have not considered the inertia support capacity of load-side resources, nor have they thoroughly analyzed the coordination relationship between system MDI and primary frequency regulation, which will result in assessment results that do not meet actual needs and pose safety hazards. This article proposes a system MDI assessment method that considers load-side resources. Establish a multi-resource aggregated system frequency response (ASFR) model that considers load-side resources to achieve fast tracking of frequency dynamic processes. The system MDI is assessed by considering the frequency dynamic constraints, which in turn explores the impact of load-side resources on the system MDI. The arithmetic analysis based on the IEEE RTS-79 system shows that the input of load-side resources can reduce the system’s inertia requirements. The assessment method proposed in this paper can accurately assess the MDI of the power system and provide a more reasonable basis for resource planning and allocation.