The Duke Energy Mitchell Ave Substation project is being done to increase reliability and to meet additional load demand for Duke Energy’s customers. Commonwealth is assisting Duke Energy with a protection and control design project which includes an existing 138/69kV transformer that is being reconfigured, relocated, and protective relaying being replaced. Additionally, there will be a new 138/13.2 kV transformer with its associated 138 kV high-side circuit switcher, and low-side 13.2 kV switchgear installed.
A 138/69 kV transformer will be relocated to a new location in the substation yard to create room for new equipment. New microprocessor protection relays will be installed to replace existing electromechanical relays protecting the 138/69 kV transformer. A new 138 kV high-side breaker will be installed with associated microprocessor protection relaying. With the relocation of the transformer and installation of a new breaker, existing bus protection will be updated. New redundant 138 kV bus protection will also be installed. A new 138 kV circuit switcher, 138/13.2 kV transformer, and 13.2 kV switchgear will be installed and all associated relay protection. Switchgear that is 13.2 kV will be installed with five breakers which will provide for three line positions and two tie positions. The existing emergency station service will be replaced with a larger unit to accommodate the increase in demand.
The substation will be in service by the end of 2019 with the engineering design done by the end of 2018.