Nonlinear Burn Control in Tokamak Fusion Reactors via Output Feedback

M.D. Boyer and E. Schuster

19th IFAC World Congress

Cape Town, South Africa, August 24-29, 2014

Abstract

The next experimental step in the development of nuclear fusion reactors is the ITER tokamak. It is designed to explore the burning plasma regime in which the plasma temperature is sustained mostly by self-heating from fusion reactions. Burn control, the control of fusion power and other reactor parameters through modulation of fueling and heating, will be essential for achieving and maintaining desired operating points and ensuring stability. Design of burn control strategies is made challenging by the multi-variable, highly nonlinear, uncertain nature of the system. Furthermore, due to the extreme conditions in fusion reactors, diagnostic systems may be limited. To deal with these challenges, we propose the use of a nonlinear, multi-variable output feedback control strategy with a proportional-integral observer. A simulation study is carried out to illustrate the performance of the scheme using a set of diagnostics likely to be available in ITER.