The substation design presented a unique challenge as the addition to the low side had separate power purchasers, while the delivery to the POI was through a shared transformer and five-mile transmission line. In addition, the wind farm had to operate as a single entity in terms of meeting voltage schedule of the transmission owner at the POI while also having the functionality of handling separate active power curtailment set-points from the independent system operator.
Ulteig’s support of a new distribution substation site and 43.8 kV transmission tap line in Buchanan, Stutsman County, North Dakota, involved performing a title search, the development of a landowner database and the creation of a landowner aerial map for the route.
Ulteig negotiated easements with landowners along the 3.5-mile route. The team also completed a land value analysis within the project corridor and drafted easement documents and legal descriptions. Finally, the team successfully negotiated and secured signatures from all landowners, acting as liaison during construction and providing project deliverables to the Central Power Electric Cooperative organization.
The collection system design involved optimizing the route so as to provide the best possible option for both the client and landowners. The 345kV/34.5kV substation contained four feeders, and it was designed to owner standards. Ulteig also provided civil engineering services including access roads, crane access routes, crane pads, delivery flow plan, intersection improvements, laydown yard, substation side, and yard site design services.
Designed wind farm 345-34.5kV substation and serviced twelve (12) 34.5kV feeders combined into six (6) feeder circuit breakers with space for additional two (2) total VAR support positions.
The two (2) 34.5kV buses were separated by a normal open MOD switch bus tie. The 345kV portion of the station was a low-profile, open air design, consisting of one (1) 345kV line termination, three (3) 345kV group operated disconnect switches, two (2) 345kV SF6 power circuit breakers, three (3) 345kV capacitive voltage transformer, and two (2) 345-34.5kV main power transformers.
A prefabricated control enclosure housed the relay panels, digital fault recorder (DFR) panel, control equipment, and supervisory control and data acquisition (SCADA) and communication equipment.
The project was needed to meet local electrical demand and is unique in that a Gas Insulated Switchgear (GIS) was utilized. A GIS is a high-voltage substation in which the major structures are contained in a sealed environment with sulfur hexafluoride gas as the insulating medium. The cutting-edge technology is often utilized where a substantial need to develop technology to make substations as compact as possible exists. The urban location of the project required a compact footprint, thus utilizing the GIS design and other urban design and construction principles. The Regulatory Permit required aesthetic screening of the substation to address public concerns, and Ulteig worked with Architectural Alliance to bring life to a 30-foot-high screen wall which shields the substation from plain view. Aesthetic landscaping was also used to beautify the site, maintaining value to the adjacent homes. In addition, a 25-foot-high sound wall was placed around the site, which reduces transformer noise, doubles as a firewall, and was constructed as a precast concrete wall. Due to the existing poor compressible soils and limited construction schedule, foundations were constructed on deep piers and micro piles. In addition, wide flange and tubular members were utilized to support electrical equipment and wall aesthetics. The project itself was complex due to the geographic and site-specific factors which had to be considered, and because of the urban location of the project, many considerations had to be given to the neighboring houses and community at large.
Minnkota Power Cooperative (MPC) partnered with Ulteig to design its new 115/25 kV substation and associated transmission line upgrade in West Fargo, North Dakota. The project involved adding a new substation to accommodate future transmission feed upgrades to 115 kV. Minnkota and Ulteig explored new materials and products for fencing and electrical materials. They also created multiple 3D renderings of the proposed project that were used for permitting and city approval of the project.
The Veteran’s Boulevard project is worthy of special recognition for going beyond the basic design for supplying power to customers. New construction materials and design methodologies were incorporated while the team innovated new ways to allow for system expansions and upgrades for years to come. The team also successfully reduced the impact on neighboring transmission and distribution lines, helping to minimize outages and costly system rework. Carefully incorporating the new design elements according to MPC and Cass County Electric Cooperative (CCEC) standards will reliably supply power to the greater Fargo community while avoiding issues with aesthetic impact and facilitating the inclusion of new commercial and residential development.
“Ulteig has continually met or exceeded all our expectations, and this project was no different,” said a representative from Minnkota Power Cooperative who worked closely with us on the project. “The team was instrumental in helping us align our own design standards with the city’s aesthetic requirements.”