Acceleration strategies for EMT Simulation of HVDC systems

• Three acceleration techniques for EMT simulation of large-scale MTDC networks. • Transmission line parallelization exploits natural decoupling for network-level speedup. • Control system parallelization distributes computational load across multiple processors. • Optimized sequential solvers improve control system efficiency with minimal CPU usage. • Hybrid approaches achieve up to 23× acceleration while maintaining accuracy. This paper investigates electromagnetic transient (EMT) simulation of large-scale multiterminal HVDC (MTDC) networks, focusing on methods for significant computational acceleration. Three key techniques are evaluated for their applicability: network parallelization, which exploits the natural decoupling properties of transmission lines; control system parallelization, which leverages modularity in converter and inverter-based resource controls; and optimized sequential solvers for control systems. Additionally, two hybrid approaches that integrate these strategies are proposed, achieving substantial speedups in simulation performance. Using the InterOPERA benchmark system modelled in EMTP®, the proposed approaches achieve up to 23x acceleration without compromising accuracy.