A ready-to-use tool for optimal selection of distribution network operating points by utilizing flexibility services for provision of distribution-level ancillary services (network peak reduction, voltage stability, N-1 criterion); defining optimal topology for operation of the distribution network based on switching states of the distribution network topology (reducing losses, maximizing reliability of supply for end users, enhancing resilience of the network, enabling provision of flexibility from network users); defining optimal set points of on-load tap changers for distribution-level transformers, providing voltage led demand response. The initial step in the tool development will be an assessment of technical demand response capability of actual distribution network of Elektra Zagreb by employing optimisation models, driven by different objective functions for providing flexible services while maintaining required technical constraints. Afterwards, an automatic reconfiguration of the MV distribution protection system will be done. Adjustable optimization tool from previously developed. The flexibility of the protection system set-up will improve reliability protection schemes will be based on the utilization of information provided by devices deployed along the grid (SCADA system) and results of the of supply, reliability of flexibility service provision as well resilience of the distribution network. This will be compared with the results obtained in the distribution grid of VIESGO in Spain.
Different modules have been partially developed by UNIZG-FER in previous project such as 3Smart (development of AC OPF modules) and DYMASOS (switching states of the distribution networks); similar solutions have been developed in DSOs around Europe. The developed solutions seem promising for improving distribution network efficiency, cost reduction and increasing hosting capacity for RES at the end-user side. The new protection reconfiguration tool will complement the development of the optimization platform and create a comprehensive platform for optimal and flexible operation of the distribution network. They will capture: i) Bidirectional current flow direction, occurring due to high penetration of DER and third-party flexibility provision; ii) changes in fault current magnitude and direction due to changes in network topology; iii) variations in fault current dynamics due to contributions of renewable energy sources; iv) increase in fault current magnitude due to contribution from synchronous units or power electronics units previously not operating in parallel with the distribution network.
Demonstration #3, Croatia (Savica, TE-TO and Resnik urban substations).