Повышение коммутационной устойчивости коллекторных тяговых электродвигателей электровозов за счет снижения пульсации тока возбуждения

Abstract

Statistics of equipment failures of electric locomotives assigned to the operational depots of the East Siberian Traction Directorate shows that about 25% of the total number of equipment failures of electric locomotives are traction electric motors (TEM); most often the collector-brush apparatus fails. The main reason is the problem of TEM low switching stability, associated with the increase in unbalanced electromotive forces (EMF) due to non-sinusoidal values of EMF variables and large phase shifts between their main harmonics. To clarify the processes related to EMF variable components, a vector diagram of their main harmonics is constructed, which determines the qualitative nature of the phenomena. It is revealed that the presence of eddy currents in the massive elements of the TEM magnetic core and the resulting armature reaction lead to significant displacement of the vector of the switching EMF, which forms the unbalanced EMF, causing violation of the TEM switching stability. In this regard, an improved system for attenuating the excitation of traction motors based on IGBT transistors is proposed, which reduces pulsation of the excitation current by at least 80% increasing the TEM life resource.