Improving the operational reliability of electric locomotives by reducing the moisture content of electric traction motor insulation based on electrokinetic phenomena

Introduction. Seasons with dominant negative ambient temperatures increase the possibility of insulation failure of electric locomotive traction motors with the service reliability of electric locomotive inevitably plummeting as a whole. Wet commutator and windings result from approximately 70% of insulation failures. The paper examines ways of improving the service reliability of electric locomotives by reducing the moisture content in the insulation of DC commutator traction motors based on electrokinetic phenomena (electroosmosis) with testing the actual parameters of the electroosmotic drying.Materials and methods. We obtained experimental data from tests on real electric traction motors in a locomotive service depot. The electroosmotic drying technology involved a device for moistening the electric motor commutator and windings developed by the authors, and standard tools for measuring the insulation resistance of electric traction motors.Results. The research shows that electroosmotic drying is feasible at a voltage of 3000 V; drying is effective with electric heater blowing; electroosmotic and electric heat drying system together increase insulation resistance by 20-40 % in the first two to three hours; electroosmotic drying shows the highest rate of increase in insulation resistance when connected to windings with a resistance below 500 kΩ; electroosmotic and electric heat drying system together use 60% less electricity and 20% less time.Discussion and conclusion. The drying technology is useful in locomotive service depots, in workshops during TR-1 maintenance and when operating traction electric rolling stock in low ambient temperatures. The drying technology is applicable in hot storage of electric locomotives; the effectiveness of this method requires experimental confirmation. This technology for increasing the resistance of wet insulation would reduce electric traction motor failures using electrokinetic phenomena, increasing reliability of electric locomotives.