Two-cascade multiloop control system of a plasma shape in a tokamak with decoupling and robust PID-controllers

Abstract

Two-cascade plasma shape control system with decoupling was designed for a linear model of a vertically elongated tokamak Globus-M2. The inner multivariable cascade controls currents in poloidal field coils, outer multivariable cascade controls plasma shape. In both cascades a decoupling matrix is used. The idea of decoupling is in reversing of matrix relationship between inputs and outputs of the system in steady-state regime. PID-controllers in the system were tuned by the QFT approach (Quantitative Feedback Theory). The obtained control system with the linear plasma model and non-linear models of current invertors as actuators for plasma position control is simulated in MatLab/Simulink environment.