Model-based Feedback Control Design Towards Robust Realization and Sustainment of Advanced Scenarios in EAST

The safety factor profile plays a critical role in the achievement of advanced tokamak scenarios, which are characterized by high confinement and the non-inductive sustainment of the plasma current necessary for steady-state operation. In order to satisfy magnetohydrodynamic stability constraints and performance requirements, the shaping of the safety factor profile usually needs to be complemented by tight control of other plasma kinetic scalars such as the plasma internal energy or the normalized β. Thus, model-based off-line (Liner-Quadratic-Integral (LQI) Control) and on-line (Model Predictive Control (MPC)) optimal feedback controllers have been developed to regulate the safety factor profile at different spatial locations, or a function of the spatial integral of this profile such as the plasma internal inductance, in combination with a set of plasma kinetic scalars. These control algorithms, which actuate the plasma current, the plasma density, the low-frequency (2.45 GHz) and high-frequency (4.60 GHz) lower-hybrid-wave powers, and the individual neutral-beam-injection powers, have been recently implemented in the EAST Plasma Control System (PCS) and tested experimentally. The to-be-reported experimental results show significant progress towards robust scenario control in EAST.