The problems of organization the protection of the DC traction network from the short-circuit faults at the high current loads

Abstract

In this paper, widely considered the problem of protection of overhead catenary from short-circuits currents. Particularly acute that problem is for the DC system, where the starting current of electric locomotives with remote short circuit currents and to distinguish them from each other is not always possible. The problems of «dead zones» and set values in the traction network are also considered. In the real world of real machinists sometimes delaying the start mode, the starting currents are reduced, and reduced increment currents during the transition to the parallel connection of traction motors and the weakening of the field. This avoids nuisance tripping speed circuit during start-up and provide protection against short-circuit currents in the zone "substation-post". Formally start mode must agree with PPTR but in fact probably possible agreement between the Traction and Power Supply Departments about the draw as the start mode, in some cases, when the setting is not otherwise choose. Most dangerous for the catenary are the lowest short-circuit currents, since they do not differ much from the current maximum normal and difficult to detect.