25 kV AC Railways Overhead Contact System Protection - A Comparison Between the Traditional Approach and Alternative Low Cost Solution

In contrast to the early days of 25 kV AC railway electrification these days new electric traction systems are usually equipped with advanced supervisory control and data acquisition (SCADA) systems as well as intelligent protection devices. Those protection devices come with communication interfaces, permit data acquisition as well as remote parameter setting according to operational needs. By utilising the modern features of the protection and SCADA systems the number of circuit breakers and associated protection equipment may be reduced significantly without compromising safety and reliability of the traction power supply. This paper compares various aspects of overhead contact system protection in the traditional 25 kV AC electric traction system against an alternative solution. Pros and cons of each approach are discussed and potential future developments are proposed.