Real-time emulation of electromagnetic transient (EMT) system involves huge computation task and requires low latency. In this paper, a Field Programmable Gate Array (FPGA)-based EMT system is proposed for small time-step emulation. This system takes advantage of fully pipelined computing structure and can support the simulation of a large-scale power grid with various types of components. Moreover, by employing our proposed node injected current accumulation (NICA) structure, the current vector updating problem in large-scale grid that involves large computation is solved, and the small time-step latency which normally takes about 10
s is brought down to only 2
s. Finally, a specified power grid system is emulated on FPGA that can support up to 74 three-phase buses with only 2
s latency for each time-step. The emulation result is also compared to other similar designs and shows the superiority of our system.