Real-Time Electromagnetic Transient Simulation of Multi-Terminal HVDC–AC Grids Based on GPU.

High-fidelity electromagnetic transient (EMT) simulation plays a critical role in understanding the dynamic behavior and fast transients involved in operation, control, and protection of multiterminal dc (MTdc) grids. This article proposes a cost-effective high-performance real-time EMT simulation platform for large-scale cross-continental MTdc grids based on graphics processing unit (GPU). Fast dynamic transients from both ac and dc networks are captured in real time with 5 μs time step, using advanced hybrid-discretized modular multilevel converter model, frequency-dependent transmission line model, and EMT-type model of synchronous generators. The proposed simulation platform i) assembles detailed EMT models of all components within an MTdc–ac grid into a single platform. This setup provides a complete simulation solution to capture fast transient signals required for high-bandwidth controller design and protection studies without any compromise; ii) implements the first GPU-based simulation architecture and corresponding algorithms for MTdc–ac grids with real-time performance at scales of 1s; iii) is highly efficient and balances the high utilization of GPU resources and low latency required for the simulation; and iv) outperforms the existing central processing unit- or digital signal processor (DSP)/field-programmable gate array-based simulators in terms of its higher scalability on large-scale MTdc–ac grids and superior price–performance ratio on the hardware. Accuracy and performance of the proposed platform are evaluated with respect to the reference results from power system computer aided design (PSCAD)/EMTdc environment. [ABSTRACT FROM AUTHOR]