Improvement of the Protective Cooperation of the DC Feeding System
Toshikatsu ITO, Jiro ITO, Satoshi ABE
There are many themes to be studied on the protection system is the DC feeding circuit than
in the AC one, because the characteristics of the former are low feeding voltage, large load
current, small difference between the load current and the fault current, parallel feeding
system, no protective wire or no negative wire, etc. They are the improvement of the protective
cooperation between the cars and the substations, the detection of high resistive earthing,
the locating of the fault point, etc. Recently we have developed a fault selective equipment
capable of selecting a fault in the car, a voltage type earthing detection equipment and
fault locator.