Development of an arcless hybrid DC fault current limiter suitable for DC railway power networks

Abstract

A hybrid current limiter device is built and tested for the railway electrical network 1500 V DC received from a power grid 20 kV AC, it is based on an ultra-fast turn-off power switch to break down the fault current as a soft transition. The advantage of both the current limiter of the saturable core reactor as a technology of superconducting fault current limiter and the artificial zero current methods of solid-state fault current limiter represent good performance, compact design, high reliability, and arcless operation. The idea behind this project is to create a hybrid DC current limiting and interrupter circuit breaker to limit the potential short circuit current to levels within a specific space and cost requirement. The hybrid breaker includes ultra-fast mechanical contacts that are actuated by power semiconductor switches for quick fault current interruption. The fault current commutation method seems to be one of the most promising current-limiting methods, and special interest is devoted to it. This paper underlines the principle of operation, analysis and experimental results obtained from work carried out on the hybrid DC current limiter.