Karzova O. Increase of efficiency of defence of power circuits of electric rolling stock composition of DC railways.

Dissertation deals with the problems of increase the efficiency of protect the main lines of electric rolling stock of DC railways from the short-circuit currents by the increase of the work speed of protective devices and their unification. For recognize of the short-circuit mode in the mains of traction motors it is suggested to apply parameter - the speed of change of the short-circuit current in the begining of its origin. This suggestion can be realized by development of protective devices on the base of modern microcontrollers. It is offered method of the determination of minimum value of set point of microprocessors protect devices of the mains of traction motors of electric rolling stock from the short-circuit currents by the criterium of speed increase of current. The scientific results which have been received allow to give the recommendation in relation of use protect devices during the modernisation of operating DC electric rolling stock and also during the development and design of new DC electric locomotives and multiple units multiple units trains.