Realtime provided Owner’s Engineering, Testing, and Commissioning for Station 255. The project was a new 345kV breaker-and-a-half air insulated substation with four (4) 345kV bays, two (2) 345/115/34.5kV auto-transformers, two (2) 115kV bays, and two (2) 34.5kV sections. It also included expansion to one (1) future 345kV bay, two (2) future transformers, and two (2) future 115kV bays.
A new 345kV line (Line 40) from Station 255 to Station 80 was installed. In order to tie the new source into the existing 115kV system, two (2) 345/115/34.5kV, 240/320/400/448MVA autotransformers and two (2) 115kV lines (940 and 941) from the new station 255 to Station 418, and to Station 23, will be installed. Both the transformers and the 115kV lines were rated for 300MVA summer normal and 550MVA summer long term emergency (LTE).
A new control house, new AC and DC systems, new communications interfaces, and all required auxiliary systems were also be installed.