Simultaneous Regulation of the Electron Temperature and Safety Factor Profiles for DIII-D using Optimal Control Methods
S. Morosohk, Z. Wang, S.T. Paruchuri, T. Rafiq, E. Schuster
65th Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Denver, CO, USA, October 30 – November 3, 2023
A controller has been designed to simultaneously regulate the electron
temperature (Te) and safety factor (q) profiles on DIII-D. Future scenario
development efforts will require the capability to control both kinetic
and magnetic profiles to achieve high performance plasmas while maintaining
MHD stability. Optimal control solutions for the regulation of the Te and
q profiles individually has been demonstrated for DIII-D [1, 2]; the controller
presented here aims to extend these results by controlling both profiles
at the same time. The controller is synthesized based on the linearized
electron heat transport and magnetic diffusion equations. Using this model,
the Linear Quadratic Integral (LQI) controller is designed to minimize
the integrated error between the actual and target profiles. The controller
has been tested in nonlinear simulations using the Control Oriented Transport
Simulator (COTSIM). Predictive simulation results demonstrate the effectiveness
of this controller in regulating both the electron temperature and safety
factor profiles simultaneously by using the available heating and current
drive sources.
[1] S. Morosohk et al., APS Division of Plasma Physics, Spokane, WA, 2022.
[2] W. Wehner et al., Fusion Engineering and Design, vol. 123, pp. 513-517, 2017.
*Supported by the US DOE (DE-SC0010661, DE-FC02-04ER54698) and by the NSF GRFP (1842163).