SELF-TUNING CONTROL STUDIES OF THE PLASMA VERTICAL POSITION PROBLEM

The plasma vertical position system in a tokamak device can be open-lo op unstable with time-varying dynamics, such that the instability incr eases with system dynamical changes. Time-varying unstable dynamics ma kes the plasma vertical position a particularly difficult one to contr ol with traditional fixed-coefficient controllers. A self-tuning techn ique offers a new solution of the plasma vertical position control pro blem by an adaptive control approach. Specifically, the self-tuning co ntroller automatically tunes the controller parameters without an a pr iori knowledge of the system dynamics and continuously tracks dynamica l changes within the system, thereby providing the system with auto-tu ning and adaptive tuning capabilities. An overview of the self-tuning methods is given, and their applicability to a simulation of the Joint European Torus (JET) vertical plasma position system is illustrated. Specifically, the applicability of pole-assignment and generalized pre dictive control self-tuning methods to the vertical plasma position sy stem is demonstrated.