230/115kV Substation Consolidation and Autotransformer Installation
Integration of a new 230/115kV autotransformer and high-voltage bus modifications to improve system flexibility and power transfer capability.
Utilities continue to invest in transmission and substation upgrades to improve grid reliability, increase power transfer capability, and support growing load demand. This project focused on consolidating two existing transmission substations into a single integrated operating station while adding new high-voltage transformation capacity to support long-term system performance.
A major investor-owned electric utility selected our team to support the consolidation effort and deliver installation of a new 230/115kV autotransformer. The project improved system flexibility, streamlined operations, and increased load transfer capability between the 230kV and 115kV systems. Scope included electrical integration of two existing bus arrangements and modifications to existing substation infrastructure.
Engineering and Construction Execution
The project required repurposing an existing transformer bay to support the new system configuration. Leveraging existing infrastructure minimized site expansion requirements while maintaining compliance with utility design standards and operational practices.
New overhead connections were installed crossing an existing 230kV transfer bus to connect the repurposed bay to a newly constructed autotransformer bay. The new bay included installation of one high-voltage circuit breaker, double-end break switching equipment, and CCVTs installed on each side of the autotransformer. Work required detailed engineering coordination, construction sequencing, and outage planning to ensure safe installation within an active transmission environment.
System Performance and Operational Impact
The completed project increased transformation capacity between the 230kV and 115kV systems and improved operational flexibility. Consolidating two substations into a single operating station simplified long-term maintenance and improved switching efficiency.
The upgraded configuration supports improved load balancing and system response during changing demand conditions while providing a scalable infrastructure platform to support future transmission and substation expansion.