Evolution of DSO control centre tools in order to maximize the value of aggregated distributed generation

A large penetration of Distributed Generation (DG) into distribution systems using a "fit and forget" approach would lead to high investment costs for system users and network operators. Offering DG access to electricity markets and ancillary services to the distribution grid, would develop new value streams for power system users. However, a significant participation of numerous small generators to electricity markets, without any visibility for power system operators, could jeopardize the power system security and safety. This paper presents how implementing the new concept of aggregating a portfolio of DG, requires DSO and TSO control tools to be adapted. DG aggregation requires the coordination of numerous small generation units, that are too small to individually bid on energy markets or provide ancillary services. In this situation, the participation and contribution of DG to electricity markets needs to be taken into account by control engineers when they monitor and control the grid. Transmission and distribution operators will have to perform new activities like real time voltage control using aggregated DG. However, the diversity and the complexity of new critical situations require control engineers to anticipate constrained situations in more efficient ways, considering the next periods of time: A day ahead of time: The participation of DG to electricity market needs to be taken into account to plan the next day operation (normal grid configuration, backup configuration, generation schedule). Operational planning tools need to be adapted or developed for that purpose; A few minutes ahead of time: Critical situations need to be detected before they occur, and control engineers need to be warned in an appropriate manner to solicit aggregated DG reserves. The paper shows that new DSO activities may be much more intimately integrated in market mechanisms than today. An analysis of the impacts on grid operation has been performed, and we focused the description of these impacts on three families of situations that could be experienced by DSOs: Aggregated DG participation to electricity market; Advanced monitoring and activation of aggregated DG reserves Real Time Volt and VAr control with aggregated DG. This work was produced by the FENIX project. The FENIX project is a collaborative R and D project, partly funded by the European Commission within the 6th Framework Program for Research, that aims at demonstrating the value and the feasibility of the concept of DG aggregation.