Operational check and control of the ASDEX upgrade poloidal field coils

The poloidal field coils of ASDEX Upgrade consisting of ohmic heating, vertical field and control coils, have to be protected. To prevent overstress by forces of thermal effects, we measure and control the timely variable currents of all coils and voltages, temperatures of the coils (Cu) and the cooling medium, water flow within all cooling loops, geometrical positions and movements of the coils and holdings, and mechanical maximum stresses of all coils. The physical quantities mentioned will be measured, whereas all mechanical stresses and coil temperatures will be calculated on line being based on current measurements and compared with critical values. (author). 3 refs.; 3 figs