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Getting power to the I-225 light rail trains

We’ve covered I-225 Rail Line Systems (the system that make the trains go) extensively with a video and an article in our newsletter, but we never had a glimpse inside a Traction Power Substation (TPSS) -- until now.

I-225 Rail Line systems engineer Shyam Bista took a trip to the Switchgear Power Systems (SPS) facility in Winneconne, Wisconsin in September.

There he got to see the production testing of the AC switchgear, which is one of two major building blocks. The AC switchgear enables the TPSS to convert AC power from the utility company, in this case Xcel Energy, to DC power via the transformer-rectifier unit. The converted electricity is then supplied to the light rail vehicles via the overhead catenary system (OCS), or power lines above the trains.

Power to the trains

The AC switchgear constantly monitors the voltage and current from Xcel, and provides protection to the TPSS in instances where current and voltage are outside of the acceptable safe range. It also provides a means to completely de-energize the TPSS for maintenance purposes.

Individual components of each building block go through a series of tests at their specific manufacturing facility.

Once the components have been assembled for each block they undergo a series of design tests. Design tests are only performed on the first unit to verify that it meets the design specifications. Some of these tests are destructive in nature and are not repeated on the rest of the units.

Once the unit has passed the design test it’ll undergo a series of production tests. After passing the design and production tests, the building blocks are shipped to a manufacturing facility in Commerce City, Colorado for final assembly inside the TPSS enclosure.

Then the complete TPSS assembly goes under a series of factory acceptance tests and is shipped to the TPSS site for final installation.

Upon installation of the TPSS in the field, it again goes through a series of field acceptance testing to make sure the wiring connections have been properly made and the unit didn't get damaged during shipping.

The production test was successfully completed for the first AC switchgear and was shipped to the substation enclosure manufacturer in Commerce City for final assembly.

The I-225 Rail Line’s first TPSS will be installed in the coming weeks. Eventually, there will be 11 of them spaced about one mile apart along the line.