FORMULATION OF PARAMETRIC COST-FUNCTIONS FOR ANCILLARY SERVICES FROM DISTRIBUTED RENEWABLE ENERGY RESOURCES IN DISTRIBUTION NETWORKS

Abstract

Conventionally, the Transmission System Operators (TSO) make use of the controllable Synchronous Generators (SG) for the provision of ancillary services (AS) in order to ensure the secure and safe operation of the electricity system, especially in case of grid emergency events. However, the increasing penetration of Distributed Renewable Energy Sources (DRES), especially in distribution grids, has resulted in the gradual decommissioning of the SGs, resulting in poor system reaction. The problem is mainly focused on the unavailability of providing AS from DRES, since they are currently regarded as uncontrollable negative loads. Nevertheless, new control algorithms have been emerged for converter-interfaced DRES, which emulate the operation of SGs. Therefore, new markets for trading AS in distribution grid level can be developed, where the DRES would play an active role. Towards this perspective, this paper proposed general parametric cost-functions based on cost-benefit analysis by dividing the AS in three general categories: AS provided by SGs (primary frequency response, voltage control), AS inherently provided by SGs (inertia, fault contribution) and new AS due to the different nature of DRES (power smoothing, harmonic mitigation). The target is to identify the cost related to each AS, in order to configure the market participation strategy.