Smooth excitation control on single-phase-direct current electric locomotives

Abstract

Increasing the energy and operational efficiency of the use of electric rolling stock is a strategic task of the locomotive complex of JSC “Russian Railways” and the company as a whole. Both tasks are solved by increasing the traction and coupling qualities of electric locomotives and increasing their energy performance. Currently, single-phase DC electric locomotives of the Traction Directorate of JSC “Russian Railways” use smooth zone-phase regulation of speed by changing voltage, to expand the range of its regulation, a change in magnetic flux is used. One of the ways to regulate the magnetic flux (magnetizing force) of the main poles of traction electric motors is a stepwise, or contactor-rheostatic method. This method does not allow using the entire area of possible changes in the magnetic flux. Three stages of magnetic flux regulation are implemented on electric locomotives of the main series of freight traffic VL80R, VL85, 2ES5K. The last position when adjusting the speed is considered a backup, it provides about 10 % of the control range. Thus, a significant drawback is obviously laid in the design. Smooth regulation of the magnetizing force of a traction electric motor allows you to expand the range of traction force regulation, improve the energy performance of an electric locomotive. The article notes other shortcomings of the traditional step-rheostat system, considers electromagnetic processes in the rectified current circuit, shows a smooth, previously undescribed method of implementing the regulation of the magnetic flux of the main poles, justifies the method of its change on the traditional element base.