Kelowna Lee Terminal Station – Transformer and Ring Bus Addition

CIMA+ was hired to design the addition of a third transformer and modifications to the 230 kV and 138 kV ring bus at the Lee terminal station in Kelowna, BC. Both the transformer and ring bus are critical components of the substation, which is responsible for delivering electricity to homes and businesses in the surrounding Kelowna area. When these components are not functioning properly, it may cause power outages and potentially disrupt the local economy.

The project involved detailed engineering and coordination with the substation owner project manager, engineering team and other stakeholders, as well as a thorough assessment of the existing infrastructure. CIMA+ provided engineering services to add a new 230/138 kV transformer with a rating of 120/160/200 MVA and reconfigured the existing 138 kV split (linear) bus at the station to a ring bus configuration that meets industry standards for this type of station.

The upgrade included the expansion of an existing 230 kV ring bus by one breaker to accommodate the additional transformer. Two new 230 kV circuit breakers were added (one of which replaced an obsolete breaker). The 138 kV bus was reconfigured from a split bus to a seven-node ring bus, with future provision for an additional two nodes. The 138 kV portion of the work included relocating four existing breakers, salvaging four obsolete breakers, and installing three new breakers. Two 138 kV breakers remained in place and the total 138 kV breaker count decreased from ten to nine. The station footprint and fence line had been revised and expanded to accommodate the reconfigured bus and provide the necessary extra space needed for ground conductors and improved perimeter drainage.

The existing 13 kV distribution bus and related equipment inside the substation were demolished and removed. Strategic electrical staging and planning allowed for maintaining power distribution to end users while new construction was completed. A new control building was designed to house new 138 kV protection and control equipment.

Our design and scheduling requirements had to accommodate seasonal demand; only one transformer off at any one time and only in shoulder seasons, only one 230 kV line off at any time during shoulder seasons and one 138 kV line out at a time, possibly seasonally also.

Stakeholder communication was a critical factor in the success of this large-scale project. Our project manager kept an open channel of communication with FortisBC’s project engineer. Our project team had weekly project meetings throughout the design. We prepared drawings for the station expansion and updated the existing drawings, including general arrangement, layout, structural steel, foundation, grounding, conduit plans, protection and controls, AC and DC schematics and wiring diagrams. These drawings are in compliance with FortisBC drafting standards. Record drawings were completed. CIMA+ provided support throughout the project construction phase. The new equipment improved the station reliability and increased its capacity, ensuring a safe and dependable power supply to Kelowna and the surrounding area.

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