Electric trains exhibit some of the highest performance among all surface modes of transportation in terms of speed, acceleration, control precision and reliability. This is so because of the very large amount of power that can be delivered to each train by means of a third rail or an overhead wire. Also, like all rail vehicles, trains have a very small friction/drag to overcome, even at high speed.
To make this high performance possible, the train power distribution system has to be designed so that it can be highly reliable and deliver the power to the trains even when some of the systems components are out or are degraded. Because of the complexity of the power distribution system, a simulation approach is generally followed to model the trains operating in different modes and headways under different component failure scenarios.
This process is illustrated using a real life project, namely the Dulles Corridor Metrorail project. A Bechtel proprietary simulation program is used to model the new rail line. A series of failure scenarios is investigated and the impact on train operations is evaluated. The purpose of this exercise was to verify that the systems components have been properly sized and specified.