TRANSMISSION 345/138KV TRANSFORMER REPLACEMENTS
PROJECT DESCRIPTION & CLIENT CHALLENGES:
Due to the age and condition of the transformer, it was determined that the transformer should be replaced. The bushings on the transformer were known to fail suddenly, which would, in turn, cause the transformer to fail. The transformer rating was also increased to 700 MVA from 560 MVA due to Substation Design standards. Using a standard design minimizes inventory and lowers O&M spending for our client. Replacing the unit with a 700 MVA unit also reduces the likelihood that it will have to be replaced in the near future due to overload on the system.
The project aligned with our client’s goals to increase the system’s reliability. Ultimately the project team decided to replace the existing 560 MVA Autotransformer with a 700 MVA transformer. The project team also replaced two 138kV breakers and associated disconnect switches with equipment having a minimum continuous capability of 3000 Amps. Our team also installed one 345kV motor-operated disconnect switch on the high side of the transformer.