The purpose of the paper is to present an improved method of active power equalization on the secondary windings of the Scott traction transformer in the power supply systems of AC railways located in the proximity to the facilities of the agroindustrial complex, gas supply systems, etc. Active power distribution using automatically controlled thyristor bridges with pulse width modulation and capacitive storage devices allows to reduce the asymmetry and unsinusoidality of currents and voltages in the primary three-phase network almost to zero at suddenly appearing and disappearing mobile traction loads, such as high-speed electric trains. To control the currents and voltages in the windings, digital filtering algorithms have been applied, which form the required number of voltage levels at a given frequency of pulse width modulation. The efficiency of these algorithms is confirmed by computer simulation in the Matlab environment. It is proposed to improve the method of power equalization on the secondary windings of the Scott traction transformer with the use of digital filtering-based automatic control algorithms. The power equalization device together with the Scott transformer ensure high quality of electric energy in the primary three-phase network in terms of asymmetry and unsinusoidality of currents and voltages, due to which electromagnetic compatibility of the traction power supply system and the power supply system of various agricultural facilities, oil and gas complex, and others located in the proximity of railways is provided.