SBIR Phase I: Optimizing Generator Reactive Power Resources

This Small Business Innovation Research (SBIR) Phase I project addresses a major ancillary service, that of optimizing generator reactive power in support of system voltage profile. The rated reactive power of generators are based on their field, stator, and end-iron heating limits. Their operating ranges are further limited by the max/min voltage limits of generator terminal, plant auxiliary motors, the system bus, and generator's protective and control systems. These voltage limits are interrelated by the tap positions on the transformers directly connected to the generator. The objective is to integrate an optimal power flow model with the generator reactive capability model for optimal selections of generator transformer taps. It is anticipated that the research would result in an analytical tool which would help the industry achieve the desired lag/lead reactive powers in support of system voltage profile. The proposed research leads to development of a power flow program that would include the actual generator reactive capability limits. Such a model would determine optimal tap settings to allow an increased supply of reactive power during transfer of large blocks of power and an increased absorption of reactive power during light-load condition, both in support of system voltage profile.