Higher voltage + more capacity = more reliability
In order for line workers and contract employees to work safely on what are extremely high-voltage power lines, Capital Electric Cooperative de-energized two substations for two weeks at a time, at different intervals. Power was re-routed to the co-op’s member-owners so they would not have a disruption of electric service.
The bucket and digger trucks don’t say Capital Electric Cooperative, but the work being done on your cooperative’s transmission system benefits all of our member-owners.
Central Power Electric Cooperative, the Minot-based wholesale electrical generation and transmission cooperative that purchased and assumed Capital Electric’s transmission and substation assets, has been making transmission upgrades based on Capital Electric’s membership growth and long-range power requirement plan. Central Power and its contract crews have been reconductoring parts of Central Power’s transmission loop around the Bismarck area. The new construction involves installing larger transmission conductor, larger transformers and other related equipment. This will increase the voltage from 41.6 kilovolts (KV) to 115 KV. Central Power’s transmission line in Capital Electric’s rural service area will remain 41.6 KV.
Phase one of the project involved upgrading the transmission loop from the North Bismarck Substation on Century Avenue to the Grandview Pines Substation located on the corner of Centennial Road and 43rd Avenue Northeast. Phase two involved upgrading the transmission loop from the Circle K Substation to the Ward Delivery Substation, both on 71st Avenue. Capital Electric line crews built temporary lines to re-route distribution services during this time frame.
The process for both projects was extensive, due to the labor and equipment involved. Rick Dressler, operations supervisor for Capital Electric, says in order to make the improvements, Capital Electric had to de-energize the power line (underbuild) below the transmission circuit. That involved re-routing power to Capital Electric members so they didn’t have a disruption of electric service. It also involved de-energizing two substations for about two weeks each at different times, so the work could be done safely by lineworkers and contract crews.
Dressler says prior to selling the transmission line and substations to Central Power, Capital Electric has had substations out of service for a couple days — but never for a couple weeks at a time.
“We’ve had one sub out for two days, and we were sweating bullets,” he says with a laugh. “We had to be very creative in how to keep power flowing to members without overloading issues. That’s one reason we waited until October when the load is low [when members are using minimal heat or air conditioning] to do these upgrades with Central Power.”
The first day Central Power took the Grandview Pines Substation offline at the end of September, it was 92 degrees.
“We couldn’t believe it,” Dressler says.
The system handled the load just fine, and both phases of the project were completed at the end of October.