Traction power supply for Tri-Met Portland Westside and Hillsboro light rail extensions

The Tri-Met Westside and Hillsboro Light Rail extensions were opened for revenue service in September, 1998. The 18 mile long line extends the existing Banfield Eastside line rail service from downtown Portland to downtown Hillsboro. Primary power is provided by the utilities at 12.5 kV and rectified by the mainline 750 kW traction power substations to deliver 750 DC power to the trains. The alignment includes at-grade street crossings, street-running operation, fully grade separated sections and a 3-mile tunnel. This paper provides a general description and discussion of the traction power supply system. The major items discussed are: dual primary feeders with automatic transfer supplying power to the tunnel traction power substations and auxiliary power systems, substation features, substation buildings, PLC controls, wayside distribution, testing and energization. Also discussed are the advantages of the built-in-place buildings versus pre-fabricated substations. These advantages include integration of the buildings with the stations where the power demand is the greatest, reduced land costs, and "hotel" loads fed from the substation auxiliary power thereby simplifying the electrical services reducing electric utility construction in the vicinity of the stations, resulting in reduced overall costs.