1.School of Electrical Engineering, Southeast University, Nanjing 210096, China;2.State Grid Wuxi Power Supply Company, Wuxi 214061, China

To fully leverage the characteristics of various types of heterogeneous distributed energy resources (DERs) and utilize the adjustable capacity of the distribution network to provide superior frequency regulation auxiliary services, this paper proposes a primary frequency control strategy of distribution-level virtual power plants (DLVPPs). First, models suitable for aggregated control are developed for grid-following and grid-forming heterogeneous DERs. Next, leveraging the derived aggregation conditions and considering factors such as the response time, system topology, and frequency regulation capacity of each DER, an adaptive disaggregation allocation strategy is employed to decompose the total expected characteristics into each DER. Then, a local controller is designed based on robust model predictive control (RMPC) to enhance the system robustness in the presence of external disturbances and model uncertainties. Meanwhile, on the premise of meeting the device-level transient constraints, each device can precisely match the local expected characteristics. Finally, simulation results demonstrate that the proposed strategy significantly improves the primary frequency regulation characteristics while considering the local dynamic characteristics, and achieves unified aggregated frequency control of heterogeneous DERs, providing an effective solution for the distribution network participating in frequency regulation auxiliary services