State-space control model of tokamak reactors

This paper deals with the modeling of tokamak nuclear fusion reactors. In order to control the creation of unstable modes in fusion processes, it is necessary to derive numerical models that are suitable for control strategies. This model addresses flux and energy conservation issues and the mechanisms behind the creation of uncontrollable modes are discussed. The dynamics of the system are given by the energy functions which solve for the currents in the structure, the plasma current and plasma position. Thus, the equations for the state variables will be derived based on the Hamiltonian equation of motion. In order to solve numerically, this model will be linearised around an operation point by taking a Newton-Raphson step. Besides, the system output will be completed by considering one equation for the flux and another for the poloidal field. Finally, the resulting low order linear model is modified so as to obtain a standard state space model verified against measuring both time and frequency domain responses.