Nonlinear Robust Burn Control in Tokamaks with Uncertainties in the Fueling Lines via Lyapunov Redesign

A. Pajares and E. Schuster

American Control Conference

Seattle, WA, USA, May 24-26, 2017

Abstract

In future burning-plasma tokamaks like ITER, one of the main problems will be controlling the plasma density and temperature during long pulses in order to regulate the fusion power density. Such problem, known as burn control, requires the development of control algorithms in which modulation of the deuterium (D) and tritium (T) fueling rates may play an important role as an actuator. However, unmeasurable variations of the D-T concentration are expected in the fueling lines during such long-pulse operation. Therefore, there will be a need for robust burn controllers that can regulate the plasma density and temperature in spite of the presence of uncertainties in the D-T concentration in the fueling lines. In this work, a nonlinear controller is presented which is able to regulate the burn condition even in the presence of the aforementioned uncertainties. The controller performance is tested in simulations for a burning-plasma ITER-like scenario.