Abstract
Switch electric drives are one of the most important and responsible components of railway automation, and therefore require the development and implementation of advanced diagnostic systems. Achievement of the goal is possible only through the use of modern mathematical and software tools. There is a problem in the use of electric motors for switch electric drives today. The point is that the nature of the load on the engine is determined by the reducer. Deterioration appears on the reducer during operation. The appearance of gaps between the gears causes the instability of the load on the shaft. Measurements and control of the size of the gaps is not performed. To solve this problem, it is proposed to use linear measurement of the gaps of the gears and further modelling of the reducer. This method will allow to determine the arising load fluctuations by the deviation of the angular velocities of rotation of the drive and driven shafts. The effect of the gaps on the system operation is shown by model in the form of transfer functions of the constituent elements and the system of equations. It will be possible to set limit values for the deterioration of the gears of the reducer by the determination the maximum deviation of shafts angular speeds of rotation in order to take measures in advance for their timely replacement and to keep the engines from excessive load.