Intelligent control of ultrafast circuit breaker for safe and reliable railway operation.

Important results from the project

The aim of the project was to develop fast and intelligent control of a fast, current-limiting circuit breaker for use in electric railway converter stations. Advantages of a very short interruption time are 1) enabling capacity increase without large investments, 2) reduced risk of train delays due to damaged equipment, alternatively lower cost for the same availability, 3) reduced risk of bodily injury and death due to fault currents through or near people - both railway workers and the general public.

Expected long term effects

The project´s expected outcome was a fast fault detection system that can trip within 1 millisecond from the fault inception. A fault detection system with trip times around 0.5 ms has been developed and successfully tested in the field, with acceptable levels of unwanted trip events. This has shown the hitherto untapped potential of using fast current-limiting breakers in electric railway applications.

Approach and implementation

The project began with the collection of technical eligibility requirements relevant for fast fault current detection. By collecting data from experts in the field, the development of the control could be based on current information about railway feeding systems in several countries. This was followed by the development of a robust control system consisting of hardware as well as software and error detection algorithms. The error detection system has been tested in the field in a railway converter station.