Experimental Assessment of Actuator Management Strategies in DIII-D
A. Pajares, E. Schuster, K. Thome, J. Barr, N. Eidietis, A. Welander, A. Hyatt, M. Walker, D. Humphreys
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Pittsburgh, PA, USA (Remote), November 8-12, 2021
Recent experiments in DIII-D have tested the capabilities of an actuator
management algorithm based on nonlinear, real-time optimization. A
multitude of control tasks will need to be carried out by a finite set
of shared actuators in reactor-grade tokamaks such as ITER. This motivates
the development and testing of actuator managers in present devices with
the ultimate goal of extrapolating these solutions to future fusion
reactors. Such actuator managers must calculate, in real time, the
commands of the tokamak actuators that fulfill the necessary control
requirements despite changing plasma conditions and actuator availability.
In this work, the actuator management problem is posed as a nonlinear
optimization problem that is solved in real time in a computationally
efficient manner. The proposed approach does not depend on particular
control objectives or actuators, facilitating the integration of the
actuator manager with independently designed controllers. Initial DIII-D
results in the steady-state high-qmin scenario have demonstrated the
capabilities of the scheme to perform both simultaneous-multiple-mission
and repurposing actuator sharing, which will be required in ITER and
future fusion reactors.
*Supported by the US DOE under DE-SC0010661 and DE-FC02-04ER54698.