In order to provide efficient performance of tokamaks with vertically elongated plasma position,
control systems for limited and diverted plasma configuration are required. The accuracy, stability, speed of
response, and reliability of plasma position control as well as plasma shape and current control depend on the
performance of the control system. Therefore, the problem of the development of such systems is an important
and actual task in modern tokamaks. In this study, the measured signals from the magnetic loops and
Rogowski coils are used to reconstruct the plasma equilibrium, for which linear models in small deviations
are constructed. We apply methods of the H∞-optimization theory to the synthesize control system for vertical
and horizontal position of plasma capable to working with structural uncertainty of the models of the
plant. These systems are applied to the plasma-physical DINA code which is configured for the tokamak
Globus-M plasma. The testing of the developed systems applied to the DINA code with Heaviside step functions
have revealed the complex dynamics of plasma magnetic configurations. Being close to the bifurcation
point in the parameter space of unstable plasma has made it possible to detect an abrupt change in the X-point
position from the top to the bottom and vice versa. Development of the methods for reconstruction of plasma
magnetic configurations and experience in designing plasma control systems with feedback for tokamaks provided
an opportunity to synthesize new digital controllers for plasma vertical and horizontal position stabilization.
It also allowed us to test the synthesized digital controllers in the closed loop of the control system with
the DINA code as a nonlinear model of plasma.