The new 230/13kV station taps two 230kV transmission lines to supply four 230/13kV transformers (two energized and two future) and two 13kV breaker and a half switchgear lineups (one energized and one future). The station layout and footprint was designed for the future build out.
The project comprised of the following equipment to be energized:
- Two 230-13.8kV transformers with associated oil containment
- Two 230kV, 4000A, 80kA dead tank circuit breakers
- Two 230kV, 4000A, 80kA disconnect switches to protect new transformers
- Relocated three existing 230kV overhead transmission circuits
- New tubular steel transmission monopole with vibratory caisson foundation
- New tubular steel A-frame line terminations with elevated switch platforms
- Maintenance platforms for equipment, switchgear, and control house
- Prefabricated Control House which consists of relay racks, SCADA and ESOC, batteries and chargers, AC and DC distribution panels, fire alarm system, lighting, HVAC system, NERC/CIP physical security, and bathroom facility
- Ground grid, station lightning protection, and site lighting 13kV sheltered aisle switchgear, which consists of two 3000A 13kV group bus, ten13kV, 18kA, 1200A feeder breakers, five 13kV, 1200A tie breakers, transformer relay protection, AC and DC panels, fire alarm 13kV underground distribution duct banks on piles from the switchgear to cast in place vault along generating station property fence
Active generation site with constrained real estate:
- We developed multiple concepts for various station locations to select station siting.
- Congested transmission right of ways: Transmission pole spotting was strategic to maintain existing railroad permits as well as stay within existing easements and avoid new station structures.
- Environmentally contaminated site: Special attention was required for design and permitting to manage contaminants.
- Extremely poor soil conditions: 100 feet deep pile foundations were required to support station foundations and structures.
- Construction in close proximity to energized 230kV: A temporary double circuit 230kV transmission bypass design as well as a detailed outage and construction sequencing was required to facilitate construction.