Prequalification of Distribution Resources in a Coordinated Market Environment

The decentralization of power systems and the rapid deployment of renewable energy sources (RES) has upgraded the role of the Distribution System Operator (DSO) from a passive network observer to an active system operator. This requires effective collaboration and coordination with the Transmission System Operator (TSO) to avoid any congestion issues in the distribution grid. In this paper, the local market coordination scheme is considered, where DSO has priority to procure services from distributed energy resources (DERs) in an optimization-based separate local market. In this framework, a prequalification scheme is proposed and developed to enable the participation of DERs in central markets without risking the stability of the distribution system. The proposed prequalification scheme allows the DSO to detect and manage congested lines in the distribution grid preventing decisions by the TSO that can threaten the distribution system stability. Simulation results on the IEEE 33-bus system illustrate the effectiveness of the prequalification scheme in managing potential congestions in the distribution grid that might occur by the actions of the TSO.