Hierarchical model predictive control in fusion reactors

Nuclear fusion still has to pass several milestones on its way to successful energy production, one of them being successful plasma stabilization. The present article presents an innovative control implementation related to plasma control for the generation of electricity with magnetically confined plasma. The implementation has been carried out over a specific device of tokamak type, called Tokamak à Configuration Variable (TCV). This novel hybrid control design allows for real time implementation of an optimal model predictive control over a large scale complex system with small time constant. At each closed loop iteration, the full model is first controlled by a straightforward controller, then the output values are used for model reduction so that finally the discretized control system is optimized only for the variables of interest. In the case of the TCV, this novel hybrid model predictive control enhances the power availability on the actuators and extends the pulse duration. Thus, this control strategy will help to achieve fusion energy stated goal of “ignition”, where nuclear fusion generates as much energy as it is needed to start the reaction.