A Command Governor approach to plasma shape control

The paper deals with the application of the so-called command governor (CG) approach to the shape control of plasmas in thermonuclear fusion reactors. A primal internal loop controlling the plasma-wall gaps is designed first and a CG device is then tuned to modify, whenever necessary, the reference to the primal loop, taking into account constraints due to voltages saturations on the converters, currents limitations in the active coils, force limits on the mechanical structures, minimum clearance between the plasma and the vacuum chamber wall, maximum induced forces on coils. The reference signal modification is accomplished through an on-line optimization procedure which embodies plasma model forecasts computed along a finite time virtual receding horizon as usual in model predictive paradigms. The ITER (International Thermonuclear Experimental Reactor) tokamak is assumed as a case study. Numerical simulations are carried out on a numerical nonlinear model taking into account almost a hundred of constraints.