DC railway substations are equipped with high-voltage DC ground relays (hereafter referred to as 64P relays) to detect DC feeding circuit ground faults within the substation compound. If a ground fault occurs at a substation or on its feeding line, however, the 64P relays of substations near the fault point may be activated, erroneously indicating that the fault has occurred at a nearby substation. This phenomenon is referred to below as a 64P relay joint fault. As feeding stops completely when a 64P relay is activated, recovery is slow and train operation may be disrupted for long periods, particularly where two or more substations are involved. In the present paper a method of detecting only bus ground faults at the substation in question without influence from faults on the feeding line or elsewhere was studied, and a new protection system for bus ground faults was developed. It has the following characteristics: 1) A discharging gap and a currentlimiting resistance are connected in series between the ground mat and rails in place of the conventional 64P relay, constituting a short circuit when a voltage equivalent to the setting value of the 64P relay is applied. 2) A fault selective relay (50N) is installed on the return wire of the substation to detect the increased rectifier current at bus ground faults. 3) Use of the logic circuit enables one to judge that a fault has occurred on the feeding line of the feeding circuit when its fault selective relay (50F) is activated, and that a bus ground fault has occurred when the 50N relay is activated and other 50F relays are not. The basic function of proposed system was confirmed through results of simulation and field tests.
Development of DC feeding bus ground fault detection system for railway substations
2005
4 Seiten, 4 Bilder
Conference paper
English
Development of a DC Feeding Bus Ground Fault Detection System for Railway Substations
Online Contents | 2005
|Development of a DC Feeding Bus Ground Fault Detection System for Railway Substations
British Library Online Contents | 2005
|Engineering Index Backfile | 1919
Engineering Index Backfile | 1921
|