San Luis Valley Substation

San Luis Valley Substation

Location: Mosca, Colo.

Client: Xcel Energy

Completion Date: Design: June 2011; Construction: December 2011

The 115-kV bay of the existing substation yard was expanded to add a new line terminal to allow for 30 megawatts (MW) of solar photovoltaic power generation to be interconnected with the power system. The existing substation yard had to be expanded to accommodate the new line terminal.

The protection and control design for this new line position was a line differential scheme via optical ground wire (OPGW) fiber to the solar facility. In addition to installing a new line position, the protection and control of the existing 115-kV main-transfer bus tie breaker and one existing line terminal were retrofitted, removing electromechanical relays and replacing them with client-specified microprocessor-based relays.