Integrated Robust Control of Individual Scalar Variables in Tokamaks
A. Pajares and E. Schuster
58th IEEE Conference on Decision and Control
Nice, France, December 11-13, 2019
Abstract
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Tokamaks are devices with a toroidal shape in which a high-temperature
ionized gas (plasma) is confined by means of helical magnetic fields.
The final goal of these devices is to obtain energy from thermonuclear
fusion reactions within this plasma. A multitude of coupled control
problems arise in tokamak-plasma research that need to be solved
simultaneously. For tokamaks to be able to operate safely while
maximizing plasma performance, integrated control schemes that can
handle different aspects of the plasma dynamics must be developed.
Moreover, due to the inherent uncertainty that exists in the plasma
modeling process, such controllers must be robust against unknown
variations of the plasma behavior. In this work, a nonlinear, robust
controller is designed for simultaneous regulation of magnetic and
kinetic scalar variables, namely the central safety factor, q0, the
edge safety factor, qedge, the total stored energy, W, and the global
toroidal rotation, Ωφ. The controller is synthesized from physics-based,
zero-dimensional (0D) models of the individual scalars’ dynamics.
One-dimensional (1D) simulations using the COTSIM (Control- Oriented
Transport Simulator) code are employed to test the proposed controller
in a DIII-D scenario.