Stability and Accuracy Analysis of a Distributed Digital Real-Time Cosimulation Infrastructure

Cosimulation techniques are gaining popularity amongst the power system research community to analyze future scalable smart grid solutions. However, complications such as multiple communication protocols, uncertainty in latencies are holding up the widespread usage of these techniques for the power system analysis. These issues are even further exacerbated when applied to digital real-time simulators (DRTSs) with strict real-time constraints for power hardware-in-the-loop (PHIL) tests. In this article, we present an innovative digital real-time cosimulation infrastructure that allows interconnecting different DRTS through the Aurora 8B/10B protocol to reduce the effects of communication latency and respect real-time constraints. The proposed solution synchronizes the DRTS interconnection by means of the IEEE 1588 precision time protocol (PTP) standard to align executions and results obtained by the cosimulated scenario. The ideal transformer method interface algorithm, commonly used in PHIL applications, is used to interface the DRTS. Finally, we present time-domain and frequency-domain accuracy analyzes on the obtained experimental results to demonstrate the potential of the proposed infrastructure. With the presented setup, a time step duration down to 50 $\mu$ s is shown to be stable and accurate in running an electromagnetic transients cosimulated power grid scenario by interconnecting two commercial DRTS (i.e., RTDS NovaCor), extending the scalability of future smart grid real-time simulations.