[en] For several decades, physicists try to get under laboratory conditions fusion of deuterium and tritium nuclei, with the aim to provide a practically inexhaustible source of energy. The present work is focused onto tokamaks only, which are torus-shaped devices with the magnetic field produced by external coils and electric current in the plasma. In the present work, a model for transport in a stochastic magnetic field is further developed and applied for modelling of plasma behaviour with EDs. This model implies that the transport towards the walls takes place predominantly along the so called 'optimal' paths. Such paths consist of a succession of segments aligned with the field lines, and segments perpendicular to them. This model provides effective transport coefficients in the form of a function of the characteristics of the stochastic field and transport perpendicular and parallel to the field lines. A second part of the work consists in the development of a model for anomalous perpendicular transport coefficients, taking into account the most important edge instabilities. These two models, for anomalous transport and for its modification in a stochastic field, are then compared with experimental temperature and density profiles from the tokamak Tore Supra in Cadarache, France, operated with an ED. In the third part of the work both models are included into the 1.5-D transport code RITM ('.5' stems for the inclusion of the toroidal geometry), for self-consistent calculation of profiles for various plasma parameters. Simulations have been performed for the conditions of experiments on the tokamak TEXTOR in Juelich, Germany, where a Dynamic ED (DED) is presently in operation. In order to validate the RITM calculations, measurements of the diamagnetic energy with a diamagnetic loop have been performed. The results of simulations, without DED and with DED in a static mode, are compared with these experimental data as well as with the radial profiles of plasma parameters measured by other diagnostics. (orig.)