Control-Oriented Modeling via Transport Analysis for Advanced Scenario Control in KSTAR

The regulation of the current profile, probably in combination with a measure of plasma internal energy, arises as one of the first fundamental control problems that must be solved to enable robust realization of advanced modes of operation in KSTAR. The high dimensionality and nonlinear magnetic-kinetic coupling of this problem motivate the use of a model-based control approach that can accommodate this complexity through embedding the known physics within the design. To achieve the scientific understanding of the current profile response dynamics in KSTAR that is necessary for control design, experiments have been recently carried out to characterize the response of the current profile to the different actuators. As an alternative to a purely data-driven modeling approach, response models suitable for model-based control design have been developed based on the Magnetic Diffusion Equation (MDE). This more physics-driven modeling approach is enabled by carrying out TRANSP-based transport analyses of the plasma-response data collected during the characterization experiments. The MDE is combined by either empirical scaling laws or transport equations for the electron density and temperature. Control applications enabled by this type of model, which include model-based optimal scenario planning, plasma state estimation from a limited set of noisy diagnostics, feedback control, and real-time prediction and optimization, will enhance present control capabilities in KSTAR.