Energy efficiency regenerative braking freight electric locomotives

The aim of the work is to study and evaluate the energy efficiency of regenerative braking of an electric locomotive when a freight train is moving at an unsteady and steady speed, to determine the degree of influence on the return of electricity of various factors, first of all, the mass of the train, the speed of movement, resistance to movement, the steepness of the slope of the track profile, driving conditions, the efficiency of traction motors and the needs of an electric locomotive own needs. Also, the purpose of the study is to develop recommendations for improving the energy efficiency of regenerative braking of an electric freight locomotive. Methods used: mathematical analysis, methods of traction calculations and energy balance. The equations of the energy balance of the movement of a freight train and its components in the mode of regenerative braking are considered, which make it possible to identify the main factors affecting the return of electricity at unsteady and steady speed. The calculated dependences of the return of electricity during regenerative braking of an electric locomotive with loaded and empty freight trains consisting of 71 four-axle cars, when moving with reduced speed and constant speed on sections of track with slopes of different steepness, characterizing the influence of individual factors on the return of electricity during regenerative braking of an electric locomotive, are obtained. It is shown that the specific return of electricity during regenerative braking of an electric locomotive with a loaded freight train weighing 7100 tons when moving with a decrease in speed on a track section with a zero profile is approximately the same as with a steady speed of movement on descents with a steepness of 6 ...7 ‰. The specific return of electricity during regenerative braking of an electric locomotive with an empty freight train weighing 1775 tons when moving with a decrease in speed on a track section with a zero profile is approximately the same as with a steady speed on descents with a steepness of 11 ‰ or more. The conditions under which the maximum return of electricity is achieved during regenerative braking of electric freight locomotives are determined. Recommendations have been developed to improve the energy efficiency of regenerative braking of electric freight locomotives.