Application of cautious stable predictive control to vertical positioning in COMPASS-D tokamak

Recent advances in guaranteed stable generalized predictive control algorit hms are applied to vertical positioning of plasma in the COMPASS-D tokamak, a test device used to study instabilities and control techniques necessary for fusion power plants in the future. The tokamak current P+D controller cannot stabilize the plasma vertical position without internal sensors whic h will not be available in larger devices. A controller which is derived,wi th the stable predictive control algorithms described in this paper stabili zes the plasma with only external sensors and also solves noise and robustn ess problems; it compares favorably to one produced with standard H-infinit y design techniques.