Current, position, and shape control of tokamak plasmas: a literature review

We present a survey of the recent literature papers dealing with the problem of designing a feedback control system for controlling the position, current, and shape of a tokamak plasma. Because of the intrinsic distributed parameter nature of this system, its dynamics are described by a set of partial differential equations (PDE) that cannot be directly used for the controller design. Therefore, the progress of the plasma control during the last two decades has been determined, on the one hand, by the capacity of the process experts to generate more and more reliable ordinary differential equations (ODE) approximate models of these dynamics, and, on the other hand, by the ability of the control specialists to use these models as a basis for model-based control design. In this paper we present a survey of the various approximate models proposed in the literature, focusing on the simplifying assumptions adopted and the controllers proposed. Prior to the literature survey we give an introduction and illustrate a general form of the PDE describing the plasma dynamics