ter reaching the maximum voltage at the 4th control zone of the rectifier-inverter converter of an AC electric locomotive, a further increase in speed is achieved by connecting the field attenuation system (FA) of traction electric motors (TEM). All domestic electric locomotives use the FA TEM system of the inductively active type with step switching. However, it has drawbacks, one of them is that step switching causes speed losses and slows down the acceleration of electric rolling stock (ERS). By 2025, the goal is to increase the speed of freight trains, which will increase freight turnover on the railway network [1]. One solution is to improve the ERS. In this regard, it is proposed to improve the standard FA TEM system of an electric locomotive by using IGBT transistors, which allow smooth regulation of the excitation current. In the article, using the graphical method of the RM, a curve of the train speed is constructed, which proves that the smooth control of the electric locomotive FA TEM allows you to quickly reach the maximum permissible speed of the electric locomotive on the section and to move at a higher speed in the ascent than with step-by-step regulation. The simulation of the 3ES5K series electric locomotive in the «Cortes» software complex on the Winter - Irkutsk-Sortirovochny section was also carried out, which proved that with the smooth regulation of the FA TEM, the technical speed of the ERS increases by at least 2,5 km/h.