Modern Technology in Traction Power Distribution System

One of the most important components of any electrified rail transit system around the world is the traction power distribution system. As a part of the Stage II Rail Improvement program that Port Authority of Allegheny County (PAAC) has implemented in 2004, the addition of four new traction power substations (TPSS), two tie-breaker stations (TBS), and 5.2 miles double-track overhead contact system (OCS) significantly contributed to the reliability and safety of rail transit services in the Greater Pittsburgh area. Since the opening of the light rail system over twenty years ago, PAAC encountered a number of challenging tasks, such as protection of a six-mile-long span from remote electrical fault while monitoring and maintaining voltage at operating level by utilizing old technology. This was accomplished by designing and building of the under-voltage protection and voltage monitoring systems. The addition of new Stage II substations at Slater Road and in Washington Junction and the Stage I Substations Voltage Upgrade project eliminated needs for these unique state-of-the-arts at that time, but high maintenance costs systems. The various improvements of Stage I and the construction of new Stage II traction power distribution systems, as well as the implementation of enhanced testing, calibration and maintenance programs, resulted in significant reduction of rail service interruptions. Modern technology allows us today to quickly diagnose and solve problems associated with malfunctioning of electrical equipment, remotely control substations and tie-breaker stations, and notify appropriate Port Authority’s personnel as well as general public about abnormal conditions of the rail system. This presentation discusses modern design, installation, and maintenance practices that PAAC implemented in recent years in the field of traction power distribution systems. The presentation also compares performance and cost-effectiveness of old verses new technologies.