Advanced Control in DIII-D: Supervisory and Fail-safe Algorithms for Future Reactor-grade Tokamaks

A. Pajares, W.P. Wehner, A.S. Welander, D. Humphreys, E. Schuster

29th IAEA Fusion Energy Conference

London, UK, October 16-21, 2023

Abstract

Supervisory, fail-safe algorithms will be necessary in ITER and future reactor-grade tokamaks where achieving numerous control objectives will rely on plant supervision and efficient actuator handling. In this work, advanced control algorithms with relevance for the next generation of tokamaks have been successfully tested in DIII-D simulations and experiments. Two algorithms have been developed in this work which have supervisory and actuator-management capabilities. The first algorithm is a reference governor, which supervises the plasma state and accordingly updates the targets in real time to ensure plant safety under feedback. The second algorithm is an actuator manager which optimizes how the tokamak actuators are used to attain the control objectives, even if actuator failures happen. These results illustrate the importance of advanced control techniques to optimize the scientific and economic output desired from reactor-grade devices, while also protecting the high investment that these plants represent.