Hooper Corporation expanded the existing 345 kV Pronghorn Switching Station located near Limon, CO to facilitate the interconnection of a new 150 MVAR STATCOM Unit. This new STATCOM unit was being added to provide reactive power compensation for voltage support on the transmission system in the area. Hooper was tasked with adding a new line position to the 345 kV ring bus and installing the new 345 kV transmission line to connect the existing Pronghorn Switching Station to the new STATCOM yard that was being constructed across the street. The new line position included the addition of a 345 kV circuit breaker, instrument transformers, surge arresters, and several 345 kV group operated disconnect switches. In addition to the overhead transmission line tie, Hooper installed over 6,000’ of concrete encased raceway system connecting the two yards as well. Both connections required very close coordination between our customer, our construction crews, and the STATCOM yard construction contractor.
Hooper’s work required a series of coordinated outages to be completed. At times, the outage sequencing required us to physically remove sections of aluminum bus and/or jumpers to isolate our work area. By taking this approach, the remaining portions of the 345 kV ring bus could be re-energized to reduce the effect to the rest of the transmission system. Certain phases of the construction required our crews to work 14 hour shifts, 7 days a week to be completed in the timeframes required. Despite some unavoidable material delivery delays, Hooper’s dedicated crew was able to complete all of the work within the outage windows and provide back-feed power to the STATCOM yard to meet all stakeholder needs.