Overview of DC traction protection scheme for Singapore rapid transit system

The Singapore rapid transit system (MRT) comprises of the North South, East West and North East lines linking seamlessly to Light Rail Systems, namely Bukit Panjang, Sengkang and Punggol LRT. The Circle Line project, presently under construction will be the latest addition to the MRT system when completed. A common feature of our MRT system is the use of DC power to meet the needs of the train traction power requirements. Unique to the use of DC power is the different types of protection required to address the different types of faults and operational scenarios within a dynamic rapid transit system (RTS). This paper presents an overview of the DC traction scheme utilised within the Singapore RTS as well as the operational scenarios that is taken into consideration in developing the DC traction scheme.