Actuator-sharing Algorithm for Simultaneous Regulation of Multiple Plasma Properties with Coupled Dynamics

S.T. Paruchuri, E. Schuster

29th IAEA Fusion Energy Conference

London, UK, October 16-21, 2023

Abstract

The plasma control system (PCS) of next-generation tokamaks like ITER and the Fusion Pilot Plant (FPP) must simultaneously regulate multiple plasma properties. Control solutions to drive individual plasma properties to their targets have been and are being developed over the years. The input commands of each control algorithm must be translated into physical actuator requests such as the auxiliary drive powers and deposition locations before implementation. Any such conversion must account for the complex coupling between the different plasma properties. The possibility of having an individual physical input affecting multiple plasma properties makes the input conversion even more challenging. This work proposes a tokamak and scenario-agnostic actuator-sharing algorithm that can convert individual controller commands into physical actuator requests while accounting for the constraints introduced by coupled plasma properties. The proposed algorithm does not rely on real-time optimization, the most commonly used method for actuator sharing and allocation, which can be computationally expensive. Furthermore, the algorithm is designed to handle real-time changes in controller objectives and actuator availability. The effectiveness of the proposed algorithm has been demonstrated using nonlinear DIII-D tokamak simulations in the Control Oriented Transport SIMulator (COTSIM).