ITER plasma current and shape control using MPC

In plasma magnetic control schemes, comprising a cascade control scheme with a plasma current and shape controller (CSC) in the outer loop and a vertical stabilisation (VS) controller in the inner loop, the main challenges are: the suppression of plasma shape transients after disturbances specific to tokamak reactors; the robustness to changes of the local dynamics; using the available chamber volume in the best possible way, so that the plasma is placed as close as possible to the plasma facing components; and tight control near power supply and gap constraints. Model predictive control (MPC) is an advanced process control approach for dealing with constraints, already established in a range of industries involving multivariable processes with slower dynamics. In this work we present an MPC controller for the ITER CSC in order to assess the feasibility of its practical implementation, and a performance evaluation in comparison to a CSC based on singular perturbation decomposition (SPD).