Coordinated deliverable energy flexibility and regulation capacity of distribution networks

The increasing capacity of distributed flexibility resources (DFRs) in power distribution systems provides an unprecedented opportunity for distribution system operators (DSOs) to offer the available distributed flexibility as services in electricity markets. This paper proposes a novel model to define and co-optimize the deliverable energy flexibility and frequency regulation capacity of power distribution systems. The distributed flexibility is provided in distribution buses by flexible loads, modeled by a novel queuing system, energy storage (ES) devices, and distributed solar resources with controllable inverters. The proposed model co-optimizes the DFRs schedule in three operating points that model the operation of flexible loads, distributed solar generation units, and ES devices in distribution networks for providing energy flexibility, as well as regulation up and down capacity in electricity markets. The proposed model takes into account the interdependence between DFRs schedule in the three operating points, which enables the DSO to provide non-conflicting capacity offers to different services in the market. In addition, the proposed model ensures the deliverability of energy flexibility and regulation capacity in the markets by satisfying the power flow constraints of distribution networks in all three operating points. The numerical studies, conducted on the 33-bus test distribution system, demonstrate the effectiveness of the proposed model for scheduling realistic energy flexibility and regulation capacity offers that are deliverable in the markets.