The Boon Lay Extension Line (BLE) is an extension of the existing MRT network. The Line extended from the existing Boon Lay station on the western end of the East-West line comprising of 2 elevated stations located along a route of approximate 3.8km. It is currently in the construction stage.This paper seeks to present the design considerations adopted in extending the power supply system to serve BLE. It discusses the 22kV power supply distribution, traction network configuration, power simulations conducted and analysis of its results. It further discusses the protection systems used within the power supply systems and the design interfaces with other systems.