Integrated Real-Time Supervisory Management for Off-Normal-Event Handling and Feedback Control of Tokamak Plasmas

For long-pulse tokamaks, one of the main challenges in the control strategy is to simultaneously reach multiple control objectives and to robustly handle in real-time (RT) unexpected events [off-normal-events (ONEs)] with a limited set of actuators. We have developed in our previous work a generic architecture of the plasma control system to deal with these issues. Due to this generic feature, we are able to extend it with an advanced supervisor: Supervisory control and Actuator Management with ONEs (SAMONE) to deal with multiple ONEs and multiple control scenarios in this work. We first standardize the evaluation of ONEs and, thereby, simplify significantly the supervisor decision logic, as well as facilitate the modifications and extensions of ONE states in the future. Then, we present the recent developments of real-time decision-making by the supervisor to switch between different control scenarios (normal, backup, shutdown, disruption mitigation, and so on) during the discharge based on ONE states. The developed SAMONE has been implemented on the TCV tokamak, applied to disruption avoidance with density limit experiments, demonstrating the excellent capabilities of the new RT integrated strategy.