Watford City Substation meets energy demand
4-year system upgrade of northwest ND complete
by Jen Neville
As Watford City celebrates its centennial year at the end of June, its community and the surrounding area can depend on reliable electricity, thanks to upgrades and additions at Western’s Watford City Substation in North Dakota. A second 230/115/13.8-kilovolt transformer was energized in April to operate in parallel with the existing transformer; this adds redundancy and capacity to the local power system.
Since 2010—when the town’s population was a third of its current size—Western started planning the rebuild and expansion of the Watford City Substation. The upgrades included interconnecting three new 115-kV customer transmission lines and increasing the voltage of Western’s two lines from 115 kV to 230 kV to support the area’s growing energy needs.
Construction to expand the Watford City Substation started in fall 2011. Project Manager Lesley Berg commented, “The load increased so much in the six months from the time the design was completed in summer 2011 to when construction was taking place in the winter of 2011/2012 that we had to modify the design to include the replacement of the [115/34.5-kV] transformer with a larger unit and the addition of two sets of 115-kV shunt capacitor banks.”
To accommodate the upgrade and design change, Western borrowed and moved equipment, including a [230/115-kV] transformer from a substation in South Dakota, to Watford City. “Also, two temporary shunt capacitor banks were borrowed from our Rocky Mountain region to install at the customer’s substation that was across the road,” said Berg.
Growing demand required another transformer
The demand for electricity continued to grow in McKenzie County and the need for a parallel 230/115-kV transformer was apparent after the system experienced peak loads in summer 2012. The original upgrade would have concluded in June 2013 with the new replacement transformer [115/34.5-kV] that has four times the capacity of the previous unit to feed the city. However, it still wouldn’t be enough, so Western started planning an additional upgrade in January 2013 to address the growing need. “The [115/34.5-kV] transformer was energized June 18, 2013, completing work for that stage of construction. Then the construction specifications for the second parallel transformer [230/115-kV] and updates were issued 10 days later,” said Berg.
230/115/13.8kV and 115/34.5kV – What do all those numbers mean?
It means that voltage of the power coursing through the lines can be adjusted from 230-kilovolts for transport to different locations and then adjusted down to distribution level 34.5-kV for the local utility to provide power to homes and local businesses in Watford City, North Dakota.
Night outages limited impact on Watford City
At the time of the upgrade, the city had only one 34.5-kV power line from the substation serving its energy needs, making outage coordination critical. The Bismarck Electrician crew installed a 115/34.5-kV mobile transformer to maintain service to the city during the transformer replacement. Western also worked with Watford City’s public works office to determine the best times for outages that would impact the fewest residents and businesses. “Through the 20 months of construction, we performed the necessary work during three night outages that were about four hours each night,” said Berg.
Regional reliability plays a part
In addition to the infrastructure in and around Watford City, Western has upgraded a few substations and transmission facilities to maintain reliable service throughout the region. Charlie Creek, Williston and Williston 2 substations form a network with Watford City Substation to move energy around the area and serve several local North Dakota towns and support the Bakken Oil Formation boom.
“We put a temporary shoo-fly around the substation to keep the 115-kV Charlie Creek-to-Watford City-to-Williston line energized during the rebuild,” said Berg. “Keeping this line intact was critical for providing voltage support to the Williston load pocket, as well as providing a source for the Watford City 115/34.5-kV transformer and station service equipment.”
Rebuilding the two sections of the Charlie Creek-to-Watford City-to-Williston 115-kV transmission lines to a 230-kV line was completed in 2009 and 2011, respectively. The line continued operate at 115-kV until work was completed at all three substations in August 2012.
“Throughout the project there has been a lot of hard work and coordination between the Upper Great Plain’s Construction, North Dakota Maintenance, Maintenance Engineering, Operations and Planning Offices,” said Berg. “The [Lakewood, Colorado] designers provided superb support throughout several scope changes. Coordination with customers concerning the design, construction schedules, equipment deliveries, outages and completion dates was crucial during the project.”