Simulation of Electric Braking Mode of a Diesel Locomotive with Series Excitation of Commutator Traction Motors Using a Power Semiconductor Converter

Purpose: To consider the structure, advantages and operating principle of a new transistor converter based on isolated gate bipolar transistors (IGBT) for diesel locomotives with commutator traction motors in the electric braking mode, as well as the implementation features of this mode on diesel locomotives. To show the functional structure of the converter automatic control system for the electric braking mode. To plot a potential braking characteristic of a diesel locomotive with a new converter. Methods: Simulation modeling of the electric braking mode using a computational mathematical model of a traction drive in the Matlab Simulink environment. Analysis of the simulation results of the traction drive operation in stationary and dynamic conditions. Comparison of the obtained braking characteristic with the existing one for 2TE25KM diesel locomotive. Results: It is established that the use of the proposed transistor traction converter in the power electrical circuit of a diesel locomotive provides axis-by-axis control of a commutator traction electric drive in the electric braking mode with series excitation of traction motors and allows to significantly increase the electric brake efficiency at low speeds. The proposed solution implements the target braking force of the locomotive in a wide range of speeds, as well as its limitations due to the electromechanical parameters of the diesel locomotive assemblies. Practical significance: It is shown that the proposed solution provides the increase of the electric brake efficiency, life extension of brake shoes and wheels of the rolling stock.