Robust Control of the Electron Temperature Profile in DIII-D
S. Morosohk, S.-T. Paruchuri, Z. Wang, T. Rafiq, E. Schuster
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Spokane, WA, USA, October 17-21, 2022
Control of kinetic profiles is crucial to achieving a high level of
plasma performance in tokamak plasmas. This requires feedback
algorithms that use measurements of the plasma state in real time to
determine the necessary actuator trajectories to reach the target
profile. To that end, a robust control scheme has been developed for
the electron temperature (Te) profile on DIII-D. A linearized model
of the dynamics of the electron temperature is derived from the heat
transport equation, and the electron density profile is modeled as an
uncertainty. The mixed-sensitivity H-infinity technique results in a
controller that is capable of tracking a target profile near the
linearization point for an expected range of uncertainty. The controller
is then tested in closed-loop nonlinear simulations by using the Control
Oriented Transport SIMulator (COTSIM). Preliminary predictive simulation
results show that this controller is indeed capable of regulating
the electron temperature profile with expected dynamic performance
and robustness.
*Supported by the US DOE (DE-SC0010661, DE-FC02-04ER54698) and by the NSF GRFP (1842163).