ROM-Based Current Profile Control in DIII-D
C. Xu, Y. Ou, E. Schuster, T.C. Luce, J. Ferron, M. Walker, D. Humphreys, T. Casper, W. Meyer
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Orlando, Florida, November 12-16, 2007
Abstract
|
|
The evolution in time of the current profile in a tokamak is related
to the evolution of the poloidal flux, which can be modeled in
cylindrical coordinates using a partial differential equation (PDE)
usually referred to as the magnetic diffusion equation. Based on
the proper orthogonal decomposition (POD) method, we propose a
reduced-order model (ROM) for the magnetic diffusion equation
(represented by an ordinary differential equation (ODE) with
constrained diffusivity-interior-boundary actuators). We use a
receding-horizon control scheme based on the reduced-order magnetic
diffusion model to design a suboptimal control law that matches as
close as possible a desired current profile within a pre-specified
interval of time. Simulation results demonstrate the efficiency of the
proposed control strategy.