Many of the same challenges presented by a retrofit project are also encountered when expanding existing stations. There are various interfaces to be designed and restrictive outages schedules that must be adhered to.
 

Factors for Bus System Expansion

When proposing long term a bus system expansion to existing substations, there are many factors that must be considered. These include increased system ratings, control and operating procedures and physical space limitations. The High Voltage Bus Systems can assist in developing a solution that addresses all of these issues.

Project Profile: Claireville Transmission Station (Ontario, Canada)

Gas-insulated substations often allow only unidirectional reductions in yard dimensions due to the space needed for incoming lines. At the Claireville Transmission Station, Hydro One reduced yard footprint in all directions with the “spaghetti junction” arrangement of the bus circuits.

A conventional station would require approximately two hundred acres of land. However, the use of gas insulated switchgear and our bus reduced the space requirement by 80 percent.

Since commissioning, the Claireville station has expanded in phases, incorporating bus system expansion to increase switching capacity. The station consists of multiple circuits of bus arranged to untangle dozens of line exit circuits and feed twenty-six 550 kV and fifty-two 250 kV GIS circuit breakers. The GIS is housed in an elevated switchgear building with the bus exiting through the floor. Incoming lines enter the station along power corridors from all directions. The High Voltage Bus Systems, in conjunction with project partners, added the following equipment to increase switching capacity at Claireville.

Bus System Expansion Details

• One bay of 250 kV GIS and three 250 kV, 4000 A line exit circuits
• One bay of 550 kV GIS and three 550 kV, 4000 A, 1800 kV BIL line exit circuits
• Three 550 kV, 1800 kV BIL bus circuits connecting to existing GIS
• Four circuits of 250 kV, 4000 A bus interfacing to existing 230 kV, 3000 A bus

Over 4000 meters of bus were supplied to the Claireville stations. Extensive use of CAD was required to ensure that the new bus system expansion would not interfere with access platforms, civil foundations, and existing equipment above and below grade.

Additional design parameters considered installation requirements, including: clearance for welded installation of bus sections, personnel access, and installation sequencing to accommodate outage schedules.

To learn more about our offerings, visit Bus Systems and Bus Services