Integrated plasma equilibrium control in RFX-mod2 via model predictive control

Magnetic confinement is widely recognized as one of the most promising strategies for achieving controlled thermonuclear fusion on Earth. Within this context, precise regulation of plasma equilibrium, including plasma current, position, and shape, is essential to ensure safe and high-performance operation of toroidal confinement devices. This paper addresses the plasma equilibrium control problem for the RFX-mod2 in tokamak configuration. We propose a model-based architecture by exploiting the model predictive control strategy in velocity form that explicitly accounts for multivariable coupling, actuator constraints of one-quadrant power converters, and external perturbations such as resistive voltage drops. The proposed approach unifies equilibrium regulation, actuator limitations, and disturbance compensation, overcoming the shortcomings of conventional two-layer control architectures. The performance of the control scheme is evaluated through an extensive set of simulation studies based on the RFX-mod2 model incorporating the CARONTE algorithm for plasma shape descriptor reconstruction, demonstrating its ability to achieve accurate equilibrium regulation while fully respecting the physical limitations of the actuators. Furthermore, the computational feasibility of the proposed controller is evaluated within the real-time Software-in-the-Loop MARTe2 framework specifically configured for RFX-mod2 operations, confirming its suitability for practical implementation.