First Experimental Results with the Current Limit Avoidance System at the JET Tokamak
The Current Limit Avoidance System (CLA) has been recently deployed at the JET tokamak to avoid current saturations in the Poloidal Field (PF) coils when the eXtreme Shape Controller is used to control the plasma shape. In order to cope with the current saturation limits, the CLA exploits the redundancy of the PF coils system to automatically obtain almost the same plasma shape using a different combination of currents in the PF coils. In the presence of disturbances it tries to avoid the current saturations by relaxing the plasma shape constraints. The CLA system has been successfully implemented on the JET tokamak and fully commissioned in 2011. This paper reports on the first experimental results achieved in 2012 during the restart and the ITER like wall campaigns at JET.