The system under consideration is the PDU contact network of high-voltage direct current from the longitudinal line at the voltage of the order of units of kHz allowing to reduce drastically the mass of power electromagnetic elements in converters and to expand the opportunities of controlling the power supply system.

The structure of traction substation 3,2 kV DC power source is considered. It is shown that the output filter choke of traction substation with voltage added converter may be excluded. A dynamic model of voltage added converter is developed, its features, as an active filter, are described.

The results of analytical research and computer design of the anomalous, steady-state and transitional modes related to the resonance in the input filter of voltage added converter based on IGBT with the PWM are presented. The ways of resonance removal by both the control means and the power blocks, combined with the overvoltage protection, are offered.

The structure of the insert of direct current on the traction substation, which makes it possible to remove a number of deficiencies in the acting feeding scheme of the overhead electric transport power line of alternating current, is proposed. Additional possibilities on improvement in the use of electrical equipment by change in the form of voltage in the overhead electric transport power line are analyzed.