Parallelization of EMT simulations for integration of inverter-based resources

This paper presents a co-simulation tool to link multiple instances of an electromagnetic transient (EMT) simulation tool for parallel and fast computations. The tool exploits the propagation delays of transmission lines and cables to create network decoupling into several smaller sub-networks. These sub-networks are solved in parallel without approximations. A multi-rate option is also incorporated, in which the sub-networks can use different numerical integration time-steps. The Functional Mock-up Interface (FMI) is used for creating the co-simulation interface between multiple instances according to a master-slave communication scheme and the data sharing method is implemented using low-level synchronization primitives called semaphores. The interfaces between each subnetwork are automatically initialized for time-domain simulations using load-flow results.