Optimal fractional-order PID control for plasma shape, position, and current in Tokamaks

Nuclear fusion is a source of safe and clean energy that motivates researchers to enhance the control strategies for better performance. In parallel, incorporating the fractional-order calculus into control strategies improves the system performance and robustness with less control effort. In this paper, optimal fractional -order proportional-integral-derivative (OFO-PID) controller is developed to control the plasma shape, position and current in Tokamaks. The OFO-PID parameters, gains and fractional-orders, are tuned using particle swarm optimization (PSO) algorithm. The main objective of the controller is to improve the magnetic system performance of TCV (tokamak a configuration variable) through guaranteeing high tracking performance. Moreover, the controller has to reduce the coupling effect between the five outputs of the system without violating the coils' voltage physical constraints in the presence of the disturbance. The tokamak simulation results show the superiority of the proposed OFO-PID over other control techniques regarding the tracking and decoupling performance.