Optimised control of the plasma position in the tokamaks ASDEX and TCV taking into consideration the phase-commutated convertor
Adjustment of the position and shape of the tokamak plasma is carried out by the use of the magnetic fields. The latter must be controlled so as to enable them to react within a few milliseconds to disturbances of the plasma current and correct them. In this work a series of practical, control-engineering solutions of the problems involved were identified and developed. Amongst these were : - a measurement technique for reliable determination of plasma position and plasma shape; - mathematical models, which describe the dynamic characteristics of the process, particular attention being given to the extreme instability of the vertical position shown by some plasmas; - equivalent controlled variables, which correct discontinuities in the disturbance-prone start-up phase of the plasma; - measurement and control matrices, subject to time-dependent control, for setpoint selection and decoupling of the individual control circuits; - procedures for investigating and optimising control circuits with phase-commutated convertors; - computer programs to optimise control circuits with tokamak plasmas; - computer-aided feedforward control for disturbance correction. Experimental results verify the mathematical models and the mode of operation of the non-linear electronic controls.
Bibliographic Reference: Report: IPP III/168 DE (1990) 110 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199110051 / Last updated on: 1994-12-02
Original language: de
Available languages: de