Aggregated Model of a Flexible Multi-Energy Distribution System for Coordinated TSO-DSO Fast Frequency Services Provision

The massive penetration of distributed energy resources (DER) encourages the provision of frequency regulation services at the distribution network level following large frequency disturbances occurring at the transmission system side. The availability of reduced-order or aggregated models will facilitate the coordination between transmission and distribution system operators. As there are no models that can capture the dynamics of diverse distributed technologies and their control systems by a unified single device model, this paper presents the single equivalent device based on the virtual synchronous machine (VSM) technology that can subsume the frequency response of different DER and loads. The validation of the proposed model is performed on the adjusted IEEE 9-bus system for different multi-energy systems. Simulated scenarios have demonstrated the accuracy of proposed aggregation with a maximum relative error of 0.1% as well as computational improvement of almost 100%.