Consideration of the Transient Resistance at the Contact System Fault Location Based on the Emergency Mode Parameters

The effect of transient resistance at the contact system fault location on the short circuit process flow pattern as a result of a change in its loop impedance is considered. An analysis of the transient impedance components for the most common types of short circuit faults in the contact network is given. It is shown that the variety of conditions determining its values complicates determination of the transient resistance for the general case by known methods, whereas this may be necessary for practical purposes. The article proposes a new method for objectively assessing the transient resistance, which consists in taking into account its value based on the parameters measured at a traction substation or a sectioning station when an emergency occurs. By using the emergency mode parameters, functional dependencies have been obtained that make it possible to determine the real transient resistance value at the fault location. These dependencies include the traction network impedances, the voltage on the traction substation or sectioning station buses, the currents of the contact system power supply lines, and the phase shift angles between them. In using the proposed method, there is no need to measure the current from the opposite side of the contact system’s faulty power supply line.