RT23 | Geographically Distributed Real-Time Co-Simulation to Support the Brazilian Interconnected Power System Operation

In recent years, alternatives to operate and integrate multiple sites of electrical network simulators, on a real-time scale, have rapidly increased. This is due to several motivators such as (1) representing large electrical power systems under different domains; (2) representing generation, transmission, and distribution networks in the same simulation frame; (3) increasing penetration of power electronics-based equipment and renewable energy sources. In this sense, the cooperative real-time simulation, aimed at applications in electrical power systems, has been expanding in studies about distributed generation, renewable resources, and performance evaluations in "smartgrid" or "microgrid". This technique, along with the integration of geographically distributed simulators, has as main focus the shared use of modeling resources and differentiated mathematical representation of the systems involved, as well as the simulation of complex and large systems. In view of the successful result achieved by the Direct Current Transmission Systems Simulator (SSCC) team at ONS in improving the interface for co-simulation between RTDS and Opal-RT platforms, located in the same lab, and the evolution to integrate remote infrastructures, ONS has been investigating alternatives to integrate with simulation centers in Brazil, notably those with greater geographic proximity to the ONS' installation within the metropolitan region of Rio de Janeiro. Therefore, this present work deals with infrastructure solutions that are being applied to integrate the Opal-RT simulators at SSCC-ONS and the Laboratory of Alternative Energy Sources (LAFAE) at Federal University of Rio de Janeiro (UFRJ) in an arrangement of geographically distributed real-time co-simulation. The technical cooperation agreement reached between ONS and LAFAE, aimed at implementing the infrastructure required for remote co-simulation between their facilities, including among other steps, the analysis of the type of electrical component interface that will be adopted considering the characteristics of communication channels available. Thus, in the first stage, two alternatives were evaluated, the first one contemplated the use of a dedicated network with deterministic latency time, and the second corresponding to the use of a shared network (Ethernet). The current stage of the work consists of mapping the data communication infrastructure solutions eligible for use, as well as investigating the possible adoption of an electrical interface between simulators based on topological decoupling by network components with latency, in this case by transmission lines of adequate length to compensating the latencies associated with data traffic on a dedicated channel and/or shared network. The adoption of a dedicated communication channel, although representing the most robust solution due to the deterministic characteristic of latency times in data traffic, comes up against, among other difficulties, service availability on the part of local providers and the cost associated with contracting it. It was demonstrated, however, that this solution applies very well to the case of different simulators located in the same installation, and the traditional EMT modeling based on instantaneous values of magnitudes can even be used. On the other hand, the adoption of an Ethernet-type shared network implies considering a stochastic characteristic for latency times and, consequently, the probable use of an electrical interface with frequency band selection, as well as the incorporation of an algorithm for the treatment of network impediments. In this sense, the work presents results with measurements of these times supported by alternative tooling to field tests for the purpose of identifying the electrical interface model to be implemented following the integration work between the SSCC-ONS and LAFAE-UFRJ facilities.