The $1.4 billion Portland-Milwaukie Light Rail (PMLR) Extension Project includes a light rail alignment that travels 7.3 miles, connecting Portland State University in downtown Portland, inner Southeast Portland, Milwaukie and North Clackamas County. Revenue service on the alignment is scheduled to begin in September 2015.
An energy storage substation (ESS) with super-capacitor technology manufactured by Siemens is being installed in place of a utility-connected substation at the Tacoma substation location to capture the energy generated by braking light rail vehicles and store it in energy savings mode, feeding it back to the traction power supply during vehicle acceleration. In voltage stabilization mode, the ESS will enable the rail system to maintain voltage system stability by ensuring the system voltage to remain within the required voltage ranges and prevent system disruptions due to low system voltage conditions.
This paper will discuss the features of the 677KW 2.5KWH Tacoma ESS including super-capacitor based energy storage system technology, ESS equipment arrangement, protection and controls. Economic benefits of cost savings in energy (KWH) consumption and power demand (KW) charges will also be discussed. Field accepting test plans and test procedures will also be presented.