Traction Power System Components

The complete traction power system consists of the following:

• Traction power substation (TPSS) that converts commercial alternating current electricity into the direct current power used by the light rail vehicles.

• Cables connecting this substation to the wayside distribution system.

• Wayside distribution system providing adequate current at appropriate voltage levels throughout the alignment. The principal element of the wayside distribution system is the overhead contact system (OCS), more commonly called the “catenary.” In some cases, there will be supplemental cables running parallel to the route to “feed” additional power to the contact wire.

• The rails, which carry the negative return current from the LRV back to the vicinity of the substation. In some cases, these will be supplemented by negative return feeder cables.

• Return system cables connecting the running rails to the substation.

• In some cases, a system of corrosion control drainage cables to collect stray traction power current and take it back to the appropriate substation. These corrosion control drainage cables are separate from and not to be confused with negative return feeder cables.