Design of a Fast Control System for the Neutral Beam Injection System at EAST

In this work, we propose and implement a high‐speed, multi‐mode control scheme for a neutral beam injection (NBI) system at the Experimental Advanced Superconducting Tokamak (EAST), encompassing open‐loop, proportional-integral-derivative (PID) feedback, and deep neural network (DNN)–based follow‐up modes. The system supports continuous, pulsed, ramp, and user‐defined waveforms and has been fully tested on a National Instruments (NI) PXI-7842 R field-programmable gate array (FPGA) under LabVIEW Real-Time (RT). With a real‐time control latency below 1 ms, it responds to a 1% (0.2 A) disturbance on a nominal 20-A beam current within 100 ms and maintains beam stability within ±5% over pulses longer than 10s. The DNN follow‐up control achieves a correlation coefficient above 0.95 between the four power supply outputs and beam power variations across 0.8 to 1.8 MW. The entire control system has now been deployed and commissioned on the EAST positive ion beam line. Future work includes extending the DNN’s valid power range beyond 1.8 MW, integrating edge computing hardware to reduce latency below 0.5 ms, and employing higher precision current sensors to shrink steady‐state error to within ±2%.