230kV Substation Expansion and Interconnection Upgrades
Brownfield expansion of an existing 230kV substation to support new transmission interconnection facilities and required network upgrades
To support new transmission interconnection requirements and maintain reliable system performance, a brownfield expansion was completed at an existing 230kV transmission substation. The project was designed to accommodate Transmission Owner Interconnection Facilities (TOIF) while also implementing required network upgrades to strengthen switching capability and protection performance within the station.
A major investor-owned electric utility selected our team to support engineering and construction coordination for the expansion and integration of new high-voltage equipment. The work was executed within an energized substation environment, requiring detailed coordination with system operations to maintain reliability throughout construction and commissioning activities.
Engineering and Equipment Installation
The project included installation of new 138kV interconnection infrastructure to support transmission interconnection facilities. Additions included one 138kV A-frame dead-end structure, three single-phase metering current transformers (CTs), and three single-phase metering potential transformers (PTs) to support metering and protection requirements. The scope also included installation of three 138kV 3000 amp center-break disconnect switches with one motor operator to support remote switching capability and operational control. A single-phase line CCVT was also installed to support voltage monitoring and system protection coordination.
In addition to interconnection scope, network upgrade work included installation of one 230kV 3000 amp gas circuit breaker and five 230kV 3000 amp center-break disconnect switches. These upgrades enhanced switching flexibility and improved fault isolation capability across the substation.
All equipment was selected and installed in accordance with utility standards to support long-term maintainability, operational consistency, and system compatibility.
System Performance and Long-Term Value
The completed expansion supports new transmission interconnection capability while improving overall substation operational flexibility. The addition of new switching and breaker infrastructure enhances system protection coordination and provides improved control of power flow through the station.
By expanding the existing 230kV yard and integrating new high-voltage equipment, the project strengthened transmission system reliability while maintaining safe operation within an active substation environment. The upgraded configuration also supports future transmission planning and provides a scalable platform for additional interconnection and network upgrade needs as system demand continues to evolve.