Open loop optimal control for plasma scenarios in the presence of eddy currents

Abstract

This paper deals with the optimization of poloidal field coil currents and voltages in a tokamak to obtain desired plasma scenarios in the presence of significant induced currents in the passive structures. These eddy currents arise in transient phases like initiation, response to disturbances, current ramp up and ramp down. The open loop control problem is solved via Linear Quadratic Optimal control implemented in the discrete-time domain. All the calculations are based on plasmaless modeling with the assumption of a nominal current distribution within a fixed sequence of plasma boundaries. The effectiveness of the proposed technique is been demonstrated with detailed nonlinear numerical simulations of a possible ITER Scenario.