DEVELOPMENT OF JT-60SA EQUILIBRIUM CONTROLLER WITH AN IMPROVED ISO-FLUX METHOD AND VERTICAL DISPLACEMENT EVENTS PREDICTOR

To resolve concerns for heat/electromagnetic loads from vertical displacement events (VDEs), we developed an equilibrium controller, which can predict and control VDEs to an arbitrary direction and allows us to cope with either upward or downward unmitigated VDEs. Here we improve the prediction rate by parameterizing a power supplies voltage saturation rate with a newly developed adaptive voltage allocation (AVA) scheme. Furthermore, the AVA scheme also broadens accessible elongation by 0.3 in the presence of power supplies voltage saturation due to hybrid plasma current and shape/position control and unknown plasmas disturbances. In preparation for coming JT-60SA integrated commissioning, the VDE predictor and the AVA scheme are implemented in our equilibrium controller, and its performance is demonstrated by using MHD Equilibrium Control Simulator “MECS”.