Electrical upgrades for a 1909 vintage hydro station

Information is provided on the electrical upgrade approach taken by Duke Power Company on one of its older hydroelectric stations, the Ninety-Nine Islands Hydro Station constructed in 1909. Equipment replaced, reasons for replacement, and the design of new equipment are discussed. Electrically, most of the original power and control equipment was still in service after nearly 80 years. Engineering studies were undertaken to evaluate not only what electrical equipment should be upgraded, but also what fundamental design changes should be made. The equipment upgrades outlined should result in improved unit reliability. Reductions in operating and maintenance costs are expected over what the costs would have been with the old equipment